linux curl命令手册

curl(1)                           curl Manual                          curl(1)

NAME
       curl - transfer a URL

SYNOPSIS
       curl [options / URLs]

DESCRIPTION
       curl  is  a tool for transferring data from or to a server. It supports
       these protocols: DICT, FILE, FTP, FTPS, GOPHER, GOPHERS,  HTTP,  HTTPS,
       IMAP,  IMAPS,  LDAP,  LDAPS, MQTT, POP3, POP3S, RTMP, RTMPS, RTSP, SCP,
       SFTP, SMB, SMBS, SMTP, SMTPS, TELNET or TFTP. The command  is  designed
       to work without user interaction.

       curl offers a busload of useful tricks like proxy support, user authen‐
       tication, FTP upload, HTTP post, SSL connections, cookies, file  trans‐
       fer resume and more. As you will see below, the number of features will
       make your head spin.

       curl is powered by  libcurl  for  all  transfer-related  features.  See
       libcurl(3) for details.

URL
       The  URL  syntax is protocol-dependent. You find a detailed description
       in RFC 3986.

       You can specify multiple URLs or parts of URLs  by  writing  part  sets
       within braces and quoting the URL as in:

         "http://site.{one,two,three}.com"

       or you can get sequences of alphanumeric series by using [] as in:

         "ftp://ftp.example.com/file[1-100].txt"

         "ftp://ftp.example.com/file[001-100].txt"    (with leading zeros)

         "ftp://ftp.example.com/file[a-z].txt"

       Nested  sequences  are not supported, but you can use several ones next
       to each other:

         "http://example.com/archive[1996-1999]/vol[1-4]/part{a,b,c}.html"

       You can specify any amount of URLs on the command line.  They  will  be
       fetched  in a sequential manner in the specified order. You can specify
       command line options and URLs mixed and in any  order  on  the  command
       line.

       You  can  specify a step counter for the ranges to get every Nth number
       or letter:

         "http://example.com/file[1-100:10].txt"

         "http://example.com/file[a-z:2].txt"

       When using [] or {
    
    } sequences when invoked from a command line  prompt,
       you probably have to put the full URL within double quotes to avoid the
       shell from interfering with it. This also  goes  for  other  characters
       treated special, like for example '&', '?' and '*'.

       Provide  the IPv6 zone index in the URL with an escaped percentage sign
       and the interface name. Like in

         "http://[fe80::3%25eth0]/"

       If you specify URL without protocol:// prefix,  curl  will  attempt  to
       guess  what  protocol  you might want. It will then default to HTTP but
       try other protocols based on often-used host name prefixes.  For  exam‐
       ple,  for  host names starting with "ftp." curl will assume you want to
       speak FTP.

       curl will do its best to use what you pass to it as a URL.  It  is  not
       trying  to  validate it as a syntactically correct URL by any means but
       is fairly liberal with what it accepts.

       curl will attempt to re-use connections for multiple file transfers, so
       that  getting many files from the same server will not do multiple con‐
       nects / handshakes. This improves speed. Of course this is only done on
       files  specified  on  a  single command line and cannot be used between
       separate curl invocations.

OUTPUT
       If not told otherwise, curl writes the received data to stdout. It  can
       be  instructed  to  instead save that data into a local file, using the
       -o, --output or -O, --remote-name options. If curl  is  given  multiple
       URLs  to  transfer on the command line, it similarly needs multiple op‐
       tions for where to save them.

       curl does not parse or otherwise "understand" the content  it  gets  or
       writes  as  output.  It does no encoding or decoding, unless explicitly
       asked to with dedicated command line options.

PROTOCOLS
       curl supports numerous protocols, or put in URL  terms:  schemes.  Your
       particular build may not support them all.

       DICT   Lets you lookup words using online dictionaries.

       FILE   Read  or  write  local  files.  curl  does not support accessing
              file:// URL remotely, but when running on Microsoft Windows  us‐
              ing the native UNC approach will work.

       FTP(S) curl  supports  the  File Transfer Protocol with a lot of tweaks
              and levers. With or without using TLS.

       GOPHER(S)
              Retrieve files.

       HTTP(S)
              curl supports HTTP with numerous options and variations. It  can
              speak HTTP version 0.9, 1.0, 1.1, 2 and 3 depending on build op‐
              tions and the correct command line options.

       IMAP(S)
              Using the mail reading protocol, curl can "download" emails  for
              you. With or without using TLS.

       LDAP(S)
              curl can do directory lookups for you, with or without TLS.

       MQTT   curl supports MQTT version 3. Downloading over MQTT equals "sub‐
              scribe" to a topic while uploading/posting equals "publish" on a
              topic. MQTT over TLS is not supported (yet).

       POP3(S)
              Downloading  from  a  pop3  server means getting a mail. With or
              without using TLS.

       RTMP(S)
              The Realtime Messaging Protocol  is  primarily  used  to  server
              streaming media and curl can download it.

       RTSP   curl supports RTSP 1.0 downloads.

       SCP    curl supports SSH version 2 scp transfers.

       SFTP   curl supports SFTP (draft 5) done over SSH version 2.

       SMB(S) curl supports SMB version 1 for upload and download.

       SMTP(S)
              Uploading  contents  to  an  SMTP server means sending an email.
              With or without TLS.

       TELNET Telling curl to fetch a telnet URL starts an interactive session
              where  it  sends  what  it  reads  on stdin and outputs what the
              server sends it.

       TFTP   curl can do TFTP downloads and uploads.

PROGRESS METER
       curl normally displays a progress meter during  operations,  indicating
       the  amount  of  transferred  data,  transfer speeds and estimated time
       left, etc. The progress meter displays number of bytes and  the  speeds
       are  in  bytes per second. The suffixes (k, M, G, T, P) are 1024 based.
       For example 1k is 1024 bytes. 1M is 1048576 bytes.

       curl displays this data to the terminal by default, so  if  you  invoke
       curl  to do an operation and it is about to write data to the terminal,
       it disables the progress meter as otherwise it would mess up the output
       mixing progress meter and response data.

       If you want a progress meter for HTTP POST or PUT requests, you need to
       redirect the response output to a file, using shell redirect  (>),  -o,
       --output or similar.

       This  does  not apply to FTP upload as that operation does not spit out
       any response data to the terminal.

       If you prefer a progress  "bar"  instead  of  the  regular  meter,  -#,
       --progress-bar  is your friend. You can also disable the progress meter
       completely with the -s, --silent option.

OPTIONS
       Options start with one or two dashes. Many of the  options  require  an
       additional value next to them.

       The  short  "single-dash"  form  of the options, -d for example, may be
       used with or without a space between it and its value, although a space
       is a recommended separator. The long "double-dash" form, -d, --data for
       example, requires a space between it and its value.

       Short version options that do not need any  additional  values  can  be
       used  immediately  next to each other, like for example you can specify
       all the options -O, -L and -v at once as -OLv.

       In general, all boolean options are enabled with --option and yet again
       disabled  with  --no-option.  That is, you use the same option name but
       prefix it with "no-". However, in this list we  mostly  only  list  and
       show the --option version of them.

       --abstract-unix-socket <path>
              (HTTP)  Connect  through an abstract Unix domain socket, instead
              of using the network.  Note: netstat shows the path  of  an  ab‐
              stract  socket  prefixed  with  '@', however the <path> argument
              should not have this leading character.

              Example:
               curl --abstract-unix-socket socketpath https://example.com

              See also --unix-socket. Added in 7.53.0.

       --alt-svc <file name>
              (HTTPS) This option enables the alt-svc parser in curl.  If  the
              file name points to an existing alt-svc cache file, that will be
              used. After a completed transfer, the cache will be saved to the
              file name again if it has been modified.

              Specify a "" file name (zero length) to avoid loading/saving and
              make curl just handle the cache in memory.

              If this option is used several times, curl  will  load  contents
              from all the files but the last one will be used for saving.

              Example:
               curl --alt-svc svc.txt https://example.com

              See also --resolve and --connect-to. Added in 7.64.1.

       --anyauth
              (HTTP) Tells curl to figure out authentication method by itself,
              and use the most secure one the remote site claims  to  support.
              This is done by first doing a request and checking the response-
              headers, thus possibly inducing  an  extra  network  round-trip.
              This  is  used  instead  of  setting  a  specific authentication
              method, which you can do with  --basic,  --digest,  --ntlm,  and
              --negotiate.

              Using --anyauth is not recommended if you do uploads from stdin,
              since it may require data to be sent twice and then  the  client
              must  be able to rewind. If the need should arise when uploading
              from stdin, the upload operation will fail.

              Used together with -u, --user.

              Example:
               curl --anyauth --user me:pwd https://example.com

              See also --proxy-anyauth, --basic and --digest.

       -a, --append
              (FTP SFTP) When used in an upload, this makes curl append to the
              target  file  instead of overwriting it. If the remote file does
              not exist, it will be created. Note that this flag is ignored by
              some SFTP servers (including OpenSSH).

              Example:
               curl --upload-file local --append ftp://example.com/

              See also -r, --range and -C, --continue-at.

       --aws-sigv4 <provider1[:provider2[:region[:service]]]>
              Use AWS V4 signature authentication in the transfer.

              The  provider argument is a string that is used by the algorithm
              when creating outgoing authentication headers.

              The region argument is a string that points to a geographic area
              of  a resources collection (region-code) when the region name is
              omitted from the endpoint.

              The service argument is a string that points to a function  pro‐
              vided by a cloud (service-code) when the service name is omitted
              from the endpoint.

              Example:
               curl --aws-sigv4 "aws:amz:east-2:es" --user "key:secret" https://example.com

              See also --basic and -u, --user. Added in 7.75.0.

       --basic
              (HTTP) Tells curl to use HTTP Basic authentication with the  re‐
              mote host. This is the default and this option is usually point‐
              less, unless you use it to override a previously set option that
              sets  a  different  authentication method (such as --ntlm, --di‐
              gest, or --negotiate).

              Used together with -u, --user.

              Example:
               curl -u name:password --basic https://example.com

              See also --proxy-basic.

       --cacert <file>
              (TLS) Tells curl to use the specified certificate file to verify
              the  peer.  The  file  may contain multiple CA certificates. The
              certificate(s) must be in PEM format. Normally curl is built  to
              use a default file for this, so this option is typically used to
              alter that default file.

              curl recognizes the environment variable named  'CURL_CA_BUNDLE'
              if  it  is  set,  and uses the given path as a path to a CA cert
              bundle. This option overrides that variable.

              The windows version of curl will automatically  look  for  a  CA
              certs file named 'curl-ca-bundle.crt', either in the same direc‐
              tory as curl.exe, or in the Current Working Directory, or in any
              folder along your PATH.

              If  curl  is  built  against  the  NSS  SSL library, the NSS PEM
              PKCS#11 module (libnsspem.so) needs to be available for this op‐
              tion to work properly.

              (iOS  and macOS only) If curl is built against Secure Transport,
              then this option is supported for  backward  compatibility  with
              other  SSL  engines,  but it should not be set. If the option is
              not set, then curl will use the certificates in the  system  and
              user  Keychain to verify the peer, which is the preferred method
              of verifying the peer's certificate chain.

              (Schannel only) This option is supported for Schannel in Windows
              7  or later with libcurl 7.60 or later. This option is supported
              for backward compatibility with other SSL engines; instead it is
              recommended  to use Windows' store of root certificates (the de‐
              fault for Schannel).

              If this option is used several times, the last one will be used.

              Example:
               curl --cacert CA-file.txt https://example.com

              See also --capath and -k, --insecure.

       --capath <dir>
              (TLS) Tells curl to use the specified certificate  directory  to
              verify  the  peer.  Multiple paths can be provided by separating
              them with ":" (e.g.  "path1:path2:path3"). The certificates must
              be  in PEM format, and if curl is built against OpenSSL, the di‐
              rectory must have been processed using the c_rehash utility sup‐
              plied  with  OpenSSL.  Using  --capath can allow OpenSSL-powered
              curl to make SSL-connections much more  efficiently  than  using
              --cacert if the --cacert file contains many CA certificates.

              If this option is set, the default capath value will be ignored,
              and if it is used several times, the last one will be used.

              Example:
               curl --capath /local/directory https://example.com

              See also --cacert and -k, --insecure.

       --cert-status
              (TLS) Tells curl to verify the status of the server  certificate
              by using the Certificate Status Request (aka. OCSP stapling) TLS
              extension.

              If this option is enabled and the server sends an invalid  (e.g.
              expired) response, if the response suggests that the server cer‐
              tificate has been revoked, or no response at  all  is  received,
              the verification fails.

              This  is  currently  only implemented in the OpenSSL, GnuTLS and
              NSS backends.

              Example:
               curl --cert-status https://example.com

              See also --pinnedpubkey. Added in 7.41.0.

       --cert-type <type>
              (TLS) Tells curl what type the provided  client  certificate  is
              using. PEM, DER, ENG and P12 are recognized types. If not speci‐
              fied, PEM is assumed.

              If this option is used several times, the last one will be used.

              Example:
               curl --cert-type PEM --cert file https://example.com

              See also -E, --cert, --key and --key-type.

       -E, --cert <certificate[:password]>
              (TLS) Tells curl to use the specified  client  certificate  file
              when getting a file with HTTPS, FTPS or another SSL-based proto‐
              col. The certificate must be in PKCS#12 format if  using  Secure
              Transport,  or  PEM format if using any other engine. If the op‐
              tional password is not specified, it will be queried for on  the
              terminal.  Note  that  this  option assumes a "certificate" file
              that is the private key and the client certificate concatenated!
              See -E, --cert and --key to specify them independently.

              If  curl  is  built against the NSS SSL library then this option
              can tell curl the nickname of the certificate to use within  the
              NSS  database defined by the environment variable SSL_DIR (or by
              default /etc/pki/nssdb). If the NSS  PEM  PKCS#11  module  (lib‐
              nsspem.so)  is  available  then  PEM files may be loaded. If you
              want to use a file from the current directory, please precede it
              with  "./"  prefix, in order to avoid confusion with a nickname.
              If the nickname contains ":", it needs to be preceded by "\"  so
              that it is not recognized as password delimiter. If the nickname
              contains "\", it needs to be escaped as "\\" so that it  is  not
              recognized as an escape character.

              If  curl is built against OpenSSL library, and the engine pkcs11
              is available, then a PKCS#11 URI (RFC 7512) can be used to spec‐
              ify  a  certificate located in a PKCS#11 device. A string begin‐
              ning with "pkcs11:" will be interpreted as a PKCS#11 URI.  If  a
              PKCS#11 URI is provided, then the --engine option will be set as
              "pkcs11" if none was provided and the --cert-type option will be
              set as "ENG" if none was provided.

              (iOS  and macOS only) If curl is built against Secure Transport,
              then the certificate string can either be the name of a certifi‐
              cate/private  key in the system or user keychain, or the path to
              a PKCS#12-encoded certificate and private key. If  you  want  to
              use  a  file  from the current directory, please precede it with
              "./" prefix, in order to avoid confusion with a nickname.

              (Schannel only) Client certificates must be specified by a  path
              expression  to  a  certificate  store.  (Loading PFX is not sup‐
              ported; you can import it to a store first). You can use "<store
              location>\<store  name>\<thumbprint>"  to refer to a certificate
              in  the  system  certificates  store,  for   example,   "Curren‐
              tUser\MY\934a7ac6f8a5d579285a74fa61e19f23ddfe8d7a".   Thumbprint
              is usually a SHA-1 hex string which you can see  in  certificate
              details.  Following  store locations are supported: CurrentUser,
              LocalMachine, CurrentService, Services,  CurrentUserGroupPolicy,
              LocalMachineGroupPolicy, LocalMachineEnterprise.

              If this option is used several times, the last one will be used.

              Example:
               curl --cert certfile --key keyfile https://example.com

              See also --cert-type, --key and --key-type.

       --ciphers <list of ciphers>
              (TLS) Specifies which ciphers to use in the connection. The list
              of ciphers must specify valid ciphers. Read  up  on  SSL  cipher
              list details on this URL:

               https://curl.se/docs/ssl-ciphers.html

              If this option is used several times, the last one will be used.

              Example:
               curl --ciphers ECDHE-ECDSA-AES256-CCM8 https://example.com

              See also --tlsv1.3.

       --compressed-ssh
              (SCP SFTP) Enables built-in SSH compression.  This is a request,
              not an order; the server may or may not do it.

              Example:
               curl --compressed-ssh sftp://example.com/

              See also --compressed. Added in 7.56.0.

       --compressed
              (HTTP) Request a compressed response using one of the algorithms
              curl supports, and automatically decompress the content. Headers
              are not modified.

              If this option is used and the server sends an  unsupported  en‐
              coding, curl will report an error. This is a request, not an or‐
              der; the server may or may not deliver data compressed.

              Example:
               curl --compressed https://example.com

              See also --compressed-ssh.

       -K, --config <file>
              Specify a text file to read curl  arguments  from.  The  command
              line  arguments  found  in the text file will be used as if they
              were provided on the command line.

              Options and their parameters must be specified on the same  line
              in the file, separated by whitespace, colon, or the equals sign.
              Long option names can optionally be given  in  the  config  file
              without the initial double dashes and if so, the colon or equals
              characters can be used as separators. If the option is specified
              with  one or two dashes, there can be no colon or equals charac‐
              ter between the option and its parameter.

              If the parameter contains whitespace (or starts with  :  or  =),
              the  parameter  must  be  enclosed  within quotes. Within double
              quotes, the following escape sequences are  available:  \\,  \",
              \t, \n, \r and \v. A backslash preceding any other letter is ig‐
              nored.

              If the first column of a config line is  a  '#'  character,  the
              rest of the line will be treated as a comment.

              Only write one option per physical line in the config file.

              Specify  the  filename  to -K, --config as '-' to make curl read
              the file from stdin.

              Note that to be able to specify a URL in the  config  file,  you
              need  to  specify  it  using the --url option, and not by simply
              writing the URL on its own line. So, it could  look  similar  to
              this:

              url = "https://curl.se/docs/"

               # --- Example file ---
               # this is a comment
               url = "example.com"
               output = "curlhere.html"
               user-agent = "superagent/1.0"

               # and fetch another URL too
               url = "example.com/docs/manpage.html"
               -O
               referer = "http://nowhereatall.example.com/"
               # --- End of example file ---

              When  curl  is invoked, it (unless -q, --disable is used) checks
              for a default config file and uses it if found,  even  when  -K,
              --config  is used. The default config file is checked for in the
              following places in this order:

              1) "$CURL_HOME/.curlrc"

              2) "$XDG_CONFIG_HOME/.curlrc" (Added in 7.73.0)

              3) "$HOME/.curlrc"

              4) Windows: "%USERPROFILE%\.curlrc"

              5) Windows: "%APPDATA%\.curlrc"

              6) Windows: "%USERPROFILE%\Application Data\.curlrc"

              7) Non-windows: use getpwuid to find the home directory

              8) On windows, if it finds no .curlrc file in the  sequence  de‐
              scribed  above,  it checks for one in the same dir the curl exe‐
              cutable is placed.

              This option can be used multiple times to load  multiple  config
              files.

              Example:
               curl --config file.txt https://example.com

              See also -q, --disable.

       --connect-timeout <fractional seconds>
              Maximum  time  in  seconds  that  you allow curl's connection to
              take.  This only limits the connection phase, so  if  curl  con‐
              nects  within the given period it will continue - if not it will
              exit.  Since version 7.32.0, this option accepts decimal values.

              If this option is used several times, the last one will be used.

              Examples:
               curl --connect-timeout 20 https://example.com
               curl --connect-timeout 3.14 https://example.com

              See also -m, --max-time.

       --connect-to <HOST1:PORT1:HOST2:PORT2>

              For  a  request  to  the  given  HOST1:PORT1  pair,  connect  to
              HOST2:PORT2 instead.  This option is suitable to direct requests
              at a specific server, e.g. at a specific cluster node in a clus‐
              ter  of  servers. This option is only used to establish the net‐
              work connection. It does NOT affect the  hostname/port  that  is
              used for TLS/SSL (e.g. SNI, certificate verification) or for the
              application protocols. "HOST1" and  "PORT1"  may  be  the  empty
              string, meaning "any host/port". "HOST2" and "PORT2" may also be
              the  empty  string,  meaning   "use   the   request's   original
              host/port".

              A "host" specified to this option is compared as a string, so it
              needs to match the name used in request URL. It  can  be  either
              numerical such as "127.0.0.1" or the full host name such as "ex‐
              ample.org".

              This option can be used many times to add many connect rules.

              Example:
               curl --connect-to example.com:443:example.net:8443 https://example.com

              See also --resolve and -H, --header. Added in 7.49.0.

       -C, --continue-at <offset>
              Continue/Resume a previous file transfer at  the  given  offset.
              The  given  offset  is  the  exact  number of bytes that will be
              skipped, counting from the beginning of the source  file  before
              it  is transferred to the destination. If used with uploads, the
              FTP server command SIZE will not be used by curl.

              Use "-C -" to tell curl to automatically find out  where/how  to
              resume  the  transfer. It then uses the given output/input files
              to figure that out.

              If this option is used several times, the last one will be used.

              Examples:
               curl -C - https://example.com
               curl -C 400 https://example.com

              See also -r, --range.

       -c, --cookie-jar <filename>
              (HTTP) Specify to which file you want curl to write all  cookies
              after  a  completed  operation. Curl writes all cookies from its
              in-memory cookie storage to the given file at the end of  opera‐
              tions.  If  no  cookies  are known, no data will be written. The
              file will be written using the Netscape cookie file  format.  If
              you set the file name to a single dash, "-", the cookies will be
              written to stdout.

              This command line option will activate the  cookie  engine  that
              makes curl record and use cookies. Another way to activate it is
              to use the -b, --cookie option.

              If the cookie jar cannot be created or  written  to,  the  whole
              curl  operation  will  not fail or even report an error clearly.
              Using -v, --verbose will get a warning displayed,  but  that  is
              the  only  visible  feedback  you get about this possibly lethal
              situation.

              If this option is used several times, the  last  specified  file
              name will be used.

              Examples:
               curl -c store-here.txt https://example.com
               curl -c store-here.txt -b read-these https://example.com

              See also -b, --cookie.

       -b, --cookie <data|filename>
              (HTTP) Pass the data to the HTTP server in the Cookie header. It
              is supposedly the data previously received from the server in  a
              "Set-Cookie:"   line.   The   data   should  be  in  the  format
              "NAME1=VALUE1; NAME2=VALUE2".

              If no '=' symbol is used in the argument, it is instead  treated
              as a filename to read previously stored cookie from. This option
              also activates the cookie engine which will make curl record in‐
              coming cookies, which may be handy if you are using this in com‐
              bination with the -L,  --location  option  or  do  multiple  URL
              transfers  on the same invoke. If the file name is exactly a mi‐
              nus ("-"), curl will instead read the contents from stdin.

              The file format of the file to read cookies from should be plain
              HTTP  headers  (Set-Cookie style) or the Netscape/Mozilla cookie
              file format.

              The file specified with -b, --cookie is only used as  input.  No
              cookies  will  be written to the file. To store cookies, use the
              -c, --cookie-jar option.

              If you use the Set-Cookie file format and do not specify  a  do‐
              main  then  the  cookie  is not sent since the domain will never
              match. To address this, set a domain in Set-Cookie  line  (doing
              that  will  include sub-domains) or preferably: use the Netscape
              format.

              This option can be used multiple times.

              Users often want to both read cookies from a file and write  up‐
              dated cookies back to a file, so using both -b, --cookie and -c,
              --cookie-jar in the same command line is common.

              Examples:
               curl -b cookiefile https://example.com
               curl -b cookiefile -c cookiefile https://example.com

              See also -c, --cookie-jar and -j, --junk-session-cookies.

       --create-dirs
              When used in conjunction with the -o, --output option, curl will
              create  the  necessary local directory hierarchy as needed. This
              option creates the directories mentioned with the  -o,  --output
              option,  nothing  else. If the --output file name uses no direc‐
              tory, or if the directories it mentions already exist, no direc‐
              tories will be created.

              Created dirs are made with mode 0750 on unix style file systems.

              To  create remote directories when using FTP or SFTP, try --ftp-
              create-dirs.

              Example:
               curl --create-dirs --output local/dir/file https://example.com

              See also --ftp-create-dirs and --output-dir.

       --create-file-mode <mode>
              (SFTP SCP FILE) When curl is used to create files remotely using
              one  of  the supported protocols, this option allows the user to
              set which 'mode' to set on the file at creation time, instead of
              the default 0644.

              This option takes an octal number as argument.

              If this option is used several times, the last one will be used.

              Example:
               curl --create-file-mode 0777 -T localfile sftp://example.com/new

              See also --ftp-create-dirs. Added in 7.75.0.

       --crlf (FTP  SMTP)  Convert  LF  to  CRLF  in  upload.  Useful  for MVS
              (OS/390).

              (SMTP added in 7.40.0)

              Example:
               curl --crlf -T file ftp://example.com/

              See also -B, --use-ascii.

       --crlfile <file>
              (TLS) Provide a file using PEM format with a Certificate Revoca‐
              tion List that may specify peer certificates that are to be con‐
              sidered revoked.

              If this option is used several times, the last one will be used.

              Example:
               curl --crlfile rejects.txt https://example.com

              See also --cacert and --capath.

       --curves <algorithm list>
              (TLS) Tells curl to request specific curves to  use  during  SSL
              session  establishment according to RFC 8422, 5.1.  Multiple al‐
              gorithms can be provided  by  separating  them  with  ":"  (e.g.
              "X25519:P-521").   The parameter is available identically in the
              "openssl s_client/s_server" utilities.

              --curves allows a OpenSSL powered curl to  make  SSL-connections
              with  exactly  the  (EC) curve requested by the client, avoiding
              nontransparent client/server negotiations.

              If this option is  set,  the  default  curves  list  built  into
              openssl will be ignored.

              Example:
               curl --curves X25519 https://example.com

              See also --ciphers. Added in 7.73.0.

       --data-ascii <data>
              (HTTP) This is just an alias for -d, --data.

              Example:
               curl --data-ascii @file https://example.com

              See also --data-binary, --data-raw and --data-urlencode.

       --data-binary <data>
              (HTTP)  This  posts data exactly as specified with no extra pro‐
              cessing whatsoever.

              If you start the data with the letter @, the rest  should  be  a
              filename. Data is posted in a similar manner as -d, --data does,
              except that newlines and carriage returns are preserved and con‐
              versions are never done.

              Like  -d,  --data the default content-type sent to the server is
              application/x-www-form-urlencoded. If you want the  data  to  be
              treated as arbitrary binary data by the server then set the con‐
              tent-type to octet-stream: -H "Content-Type:  application/octet-
              stream".

              If  this  option  is  used several times, the ones following the
              first will append data as described in -d, --data.

              Example:
               curl --data-binary @filename https://example.com

              See also --data-ascii.

       --data-raw <data>
              (HTTP) This posts data similarly to -d, --data but  without  the
              special interpretation of the @ character.

              Examples:
               curl --data-raw "hello" https://example.com
               curl --data-raw "@at@at@" https://example.com

              See also -d, --data. Added in 7.43.0.

       --data-urlencode <data>
              (HTTP)  This posts data, similar to the other -d, --data options
              with the exception that this performs URL-encoding.

              To be CGI-compliant, the <data> part should begin  with  a  name
              followed  by a separator and a content specification. The <data>
              part can be passed to curl using one of the following syntaxes:

              content
                     This will make curl URL-encode the content and pass  that
                     on.  Just be careful so that the content does not contain
                     any = or @ symbols, as that will  then  make  the  syntax
                     match one of the other cases below!

              =content
                     This  will make curl URL-encode the content and pass that
                     on. The preceding = symbol is not included in the data.

              name=content
                     This will make curl URL-encode the content part and  pass
                     that  on.  Note that the name part is expected to be URL-
                     encoded already.

              @filename
                     This will make curl load data from the  given  file  (in‐
                     cluding  any  newlines), URL-encode that data and pass it
                     on in the POST.

              name@filename
                     This will make curl load data from the  given  file  (in‐
                     cluding  any  newlines), URL-encode that data and pass it
                     on in the POST. The name part  gets  an  equal  sign  ap‐
                     pended,  resulting  in name=urlencoded-file-content. Note
                     that the name is expected to be URL-encoded already.

       Examples:
        curl --data-urlencode name=val https://example.com
        curl --data-urlencode =encodethis https://example.com
        curl --data-urlencode name@file https://example.com
        curl --data-urlencode @fileonly https://example.com

       See also -d, --data and --data-raw.

       -d, --data <data>
              (HTTP MQTT) Sends the specified data in a POST  request  to  the
              HTTP server, in the same way that a browser does when a user has
              filled in an HTML form and presses the submit button. This  will
              cause curl to pass the data to the server using the content-type
              application/x-www-form-urlencoded. Compare to -F, --form.

              --data-raw is almost the same but does not have a special inter‐
              pretation  of  the  @ character. To post data purely binary, you
              should instead use the --data-binary option. To  URL-encode  the
              value of a form field you may use --data-urlencode.

              If  any of these options is used more than once on the same com‐
              mand line, the data pieces specified will be merged with a sepa‐
              rating  &-symbol.  Thus,  using  '-d name=daniel -d skill=lousy'
              would    generate    a    post    chunk    that    looks    like
              'name=daniel&skill=lousy'.

              If  you  start  the data with the letter @, the rest should be a
              file name to read the data from, or - if you want curl  to  read
              the  data  from  stdin.  Posting data from a file named 'foobar'
              would thus be done with -d, --data @foobar. When -d,  --data  is
              told  to  read  from a file like that, carriage returns and new‐
              lines will be stripped out. If you do not want the  @  character
              to have a special interpretation use --data-raw instead.

              Examples:
               curl -d "name=curl" https://example.com
               curl -d "name=curl" -d "tool=cmdline" https://example.com
               curl -d @filename https://example.com

              See  also  --data-binary,  --data-urlencode and --data-raw. This
              option overrides -F, --form and -I,  --head  and  -T,  --upload-
              file.

       --delegation <LEVEL>
              (GSS/kerberos)  Set  LEVEL to tell the server what it is allowed
              to delegate when it comes to user credentials.

              none   Do not allow any delegation.

              policy Delegates if and only if the OK-AS-DELEGATE flag  is  set
                     in  the  Kerberos  service  ticket,  which is a matter of
                     realm policy.

              always Unconditionally allow the server to delegate.

       If this option is used several times, the last one will be used.

       Example:
        curl --delegation "none" https://example.com

       See also -k, --insecure and --ssl.

       --digest
              (HTTP) Enables HTTP Digest authentication. This is an  authenti‐
              cation  scheme  that  prevents the password from being sent over
              the wire in clear text. Use this in combination with the  normal
              -u, --user option to set user name and password.

              If  this  option  is  used  several times, only the first one is
              used.

              Example:
               curl -u name:password --digest https://example.com

              See also -u, --user, --proxy-digest and --anyauth.  This  option
              overrides --basic and --ntlm and --negotiate.

       --disable-eprt
              (FTP) Tell curl to disable the use of the EPRT and LPRT commands
              when doing active FTP transfers. Curl will normally always first
              attempt  to use EPRT, then LPRT before using PORT, but with this
              option, it will use PORT right away. EPRT and  LPRT  are  exten‐
              sions  to  the  original  FTP  protocol, and may not work on all
              servers, but they enable more functionality in a better way than
              the traditional PORT command.

              --eprt can be used to explicitly enable EPRT again and --no-eprt
              is an alias for --disable-eprt.

              If the server is accessed using IPv6, this option will  have  no
              effect as EPRT is necessary then.

              Disabling  EPRT only changes the active behavior. If you want to
              switch to passive mode you need to not  use  -P,  --ftp-port  or
              force it with --ftp-pasv.

              Example:
               curl --disable-eprt ftp://example.com/

              See also --disable-epsv and -P, --ftp-port.

       --disable-epsv
              (FTP)  Tell curl to disable the use of the EPSV command when do‐
              ing passive FTP transfers. Curl will normally always  first  at‐
              tempt to use EPSV before PASV, but with this option, it will not
              try using EPSV.

              --epsv can be used to explicitly enable EPSV again and --no-epsv
              is an alias for --disable-epsv.

              If  the  server is an IPv6 host, this option will have no effect
              as EPSV is necessary then.

              Disabling EPSV only changes the passive behavior. If you want to
              switch to active mode you need to use -P, --ftp-port.

              Example:
               curl --disable-epsv ftp://example.com/

              See also --disable-eprt and -P, --ftp-port.

       -q, --disable
              If  used  as the first parameter on the command line, the curlrc
              config file will not be read and used. See the -K, --config  for
              details on the default config file search path.

              Example:
               curl -q https://example.com

              See also -K, --config.

       --disallow-username-in-url
              (HTTP)  This  tells  curl  to  exit if passed a url containing a
              username. This is probably most useful when  the  URL  is  being
              provided at run-time or similar.

              Example:
               curl --disallow-username-in-url https://example.com

              See also --proto. Added in 7.61.0.

       --dns-interface <interface>
              (DNS)  Tell  curl  to send outgoing DNS requests through <inter‐
              face>. This option is a counterpart to --interface  (which  does
              not  affect  DNS). The supplied string must be an interface name
              (not an address).

              Example:
               curl --dns-interface eth0 https://example.com

              See also --dns-ipv4-addr  and  --dns-ipv6-addr.  --dns-interface
              requires  that  the  underlying  libcurl was built to support c-
              ares. Added in 7.33.0.

       --dns-ipv4-addr <address>
              (DNS) Tell curl to bind to <ip-address> when making IPv4 DNS re‐
              quests,  so  that  the DNS requests originate from this address.
              The argument should be a single IPv4 address.

              If this option is used several times, the last one will be used.

              Example:
               curl --dns-ipv4-addr 10.1.2.3 https://example.com

              See also --dns-interface  and  --dns-ipv6-addr.  --dns-ipv4-addr
              requires  that  the  underlying  libcurl was built to support c-
              ares. Added in 7.33.0.

       --dns-ipv6-addr <address>
              (DNS) Tell curl to bind to <ip-address> when making IPv6 DNS re‐
              quests,  so  that  the DNS requests originate from this address.
              The argument should be a single IPv6 address.

              If this option is used several times, the last one will be used.

              Example:
               curl --dns-ipv6-addr 2a04:4e42::561 https://example.com

              See also --dns-interface  and  --dns-ipv4-addr.  --dns-ipv6-addr
              requires  that  the  underlying  libcurl was built to support c-
              ares. Added in 7.33.0.

       --dns-servers <addresses>
              Set the list of DNS servers to be used instead of the system de‐
              fault.   The  list of IP addresses should be separated with com‐
              mas. Port numbers may also optionally be given as :<port-number>
              after each IP address.

              If this option is used several times, the last one will be used.

              Example:
               curl --dns-servers 192.168.0.1,192.168.0.2 https://example.com

              See  also --dns-interface and --dns-ipv4-addr. --dns-servers re‐
              quires that the underlying libcurl was built to support  c-ares.
              Added in 7.33.0.

       --doh-cert-status
              Same as --cert-status but used for DoH (DNS-over-HTTPS).

              Example:
               curl --doh-cert-status --doh-url https://doh.example https://example.com

              See also --doh-insecure. Added in 7.76.0.

       --doh-insecure
              Same as -k, --insecure but used for DoH (DNS-over-HTTPS).

              Example:
               curl --doh-insecure --doh-url https://doh.example https://example.com

              See also --doh-url. Added in 7.76.0.

       --doh-url <URL>
              Specifies  which  DNS-over-HTTPS  (DoH) server to use to resolve
              hostnames, instead of using the default name resolver mechanism.
              The URL must be HTTPS.

              Some  SSL  options  that you set for your transfer will apply to
              DoH since the name lookups take place  over  SSL.  However,  the
              certificate  verification  settings are not inherited and can be
              controlled separately via --doh-insecure and --doh-cert-status.

              If this option is used several times, the last one will be used.

              Example:
               curl --doh-url https://doh.example https://example.com

              See also --doh-insecure. Added in 7.62.0.

       -D, --dump-header <filename>
              (HTTP FTP) Write the received protocol headers to the  specified
              file.  If  no  headers are received, the use of this option will
              create an empty file.

              When used in FTP, the FTP server response lines  are  considered
              being "headers" and thus are saved there.

              If this option is used several times, the last one will be used.

              Example:
               curl --dump-header store.txt https://example.com

              See also -o, --output.

       --egd-file <file>
              (TLS)  Specify  the  path  name  to the Entropy Gathering Daemon
              socket. The socket is used to seed the  random  engine  for  SSL
              connections.

              Example:
               curl --egd-file /random/here https://example.com

              See also --random-file.

       --engine <name>
              (TLS)  Select the OpenSSL crypto engine to use for cipher opera‐
              tions. Use --engine list to print a list of build-time supported
              engines.  Note  that  not all (and possibly none) of the engines
              may be available at run-time.

              Example:
               curl --engine flavor https://example.com

              See also --ciphers and --curves.

       --etag-compare <file>
              (HTTP) This option makes a conditional HTTP request for the spe‐
              cific ETag read from the given file by sending a custom If-None-
              Match header using the stored ETag.

              For correct results, make sure that the specified file  contains
              only  a  single  line  with  the  desired ETag. An empty file is
              parsed as an empty ETag.

              Use the option --etag-save to first save the  ETag  from  a  re‐
              sponse,  and  then  use this option to compare against the saved
              ETag in a subsequent request.

              Example:
               curl --etag-compare etag.txt https://example.com

              See also --etag-save and -z, --time-cond. Added in 7.68.0.

       --etag-save <file>
              (HTTP) This option saves an HTTP ETag to the specified file.  An
              ETag  is  a  caching  related  header, usually returned in a re‐
              sponse.

              If no ETag is sent by the server, an empty file is created.

              Example:
               curl --etag-save storetag.txt https://example.com

              See also --etag-compare. Added in 7.68.0.

       --expect100-timeout <seconds>
              (HTTP) Maximum time in seconds that you allow curl to wait for a
              100-continue  response  when curl emits an Expects: 100-continue
              header in its request. By default curl  will  wait  one  second.
              This  option accepts decimal values! When curl stops waiting, it
              will continue as if the response has been received.

              Example:
               curl --expect100-timeout 2.5 -T file https://example.com

              See also --connect-timeout. Added in 7.47.0.

       --fail-early
              Fail and exit on the first detected transfer error.

              When curl is used to do multiple transfers on the command  line,
              it will attempt to operate on each given URL, one by one. By de‐
              fault, it will ignore errors if there are more  URLs  given  and
              the  last  URL's  success will determine the error code curl re‐
              turns. So early failures will be "hidden" by subsequent success‐
              ful transfers.

              Using  this  option,  curl  will  instead return an error on the
              first transfer that fails, independent of  the  amount  of  URLs
              that  are given on the command line. This way, no transfer fail‐
              ures go undetected by scripts and similar.

              This option is global and does not need to be specified for each
              use of -:, --next.

              This option does not imply -f, --fail, which causes transfers to
              fail due to the server's HTTP status code. You can  combine  the
              two options, however note -f, --fail is not global and is there‐
              fore contained by -:, --next.

              Example:
               curl --fail-early https://example.com https://two.example

              See also -f, --fail and --fail-with-body. Added in 7.52.0.

       --fail-with-body
              (HTTP) Return an error on server errors where the HTTP  response
              code  is  400  or  greater). In normal cases when an HTTP server
              fails to deliver a document, it returns an HTML document stating
              so  (which  often  also  describes why and more). This flag will
              still allow curl to output and save that content but also to re‐
              turn error 22.

              This  is  an  alternative  option to -f, --fail which makes curl
              fail for the same circumstances but without saving the content.

              Example:
               curl --fail-with-body https://example.com

              See also -f, --fail. Added in 7.76.0.

       -f, --fail
              (HTTP) Fail silently (no output at all) on server  errors.  This
              is  mostly done to enable scripts etc to better deal with failed
              attempts. In normal cases when an HTTP server fails to deliver a
              document,  it  returns  an HTML document stating so (which often
              also describes why and more). This flag will prevent  curl  from
              outputting that and return error 22.

              This  method is not fail-safe and there are occasions where non-
              successful response codes will slip through, especially when au‐
              thentication is involved (response codes 401 and 407).

              Example:
               curl --fail https://example.com

              See also --fail-with-body.

       --false-start
              (TLS)  Tells  curl  to use false start during the TLS handshake.
              False start is a mode where a TLS client will start sending  ap‐
              plication  data  before verifying the server's Finished message,
              thus saving a round trip when performing a full handshake.

              This is currently only implemented in the NSS and Secure  Trans‐
              port (on iOS 7.0 or later, or OS X 10.9 or later) backends.

              Example:
               curl --false-start https://example.com

              See also --tcp-fastopen. Added in 7.42.0.

       --form-escape
              (HTTP)  Tells curl to pass on names of multipart form fields and
              files using backslash-escaping instead of percent-encoding.

              Example:
               curl --form-escape --form 'field\name=curl' 'file=@load"this' https://example.com

              See also -F, --form. Added in 7.81.0.

       --form-string <name=string>
              (HTTP SMTP IMAP) Similar to -F, --form  except  that  the  value
              string  for  the  named parameter is used literally. Leading '@'
              and '<' characters, and the ';type=' string in the value have no
              special meaning. Use this in preference to -F, --form if there's
              any possibility that the string value may  accidentally  trigger
              the '@' or '<' features of -F, --form.

              Example:
               curl --form-string "data" https://example.com

              See also -F, --form.

       -F, --form <name=content>
              (HTTP  SMTP  IMAP) For HTTP protocol family, this lets curl emu‐
              late a filled-in form in which a user  has  pressed  the  submit
              button.  This  causes  curl  to POST data using the Content-Type
              multipart/form-data according to RFC 2388.

              For SMTP and IMAP protocols, this is the means to compose a mul‐
              tipart mail message to transmit.

              This  enables  uploading of binary files etc. To force the 'con‐
              tent' part to be a file, prefix the file name with an @ sign. To
              just get the content part from a file, prefix the file name with
              the symbol <. The difference between @ and  <  is  then  that  @
              makes  a  file  get attached in the post as a file upload, while
              the < makes a text field and just get the contents for that text
              field from a file.

              Tell  curl to read content from stdin instead of a file by using
              - as filename. This goes for both @ and < constructs. When stdin
              is used, the contents is buffered in memory first by curl to de‐
              termine its size and allow a possible resend. Defining a  part's
              data from a named non-regular file (such as a named pipe or sim‐
              ilar) is unfortunately not subject to buffering and will be  ef‐
              fectively  read at transmission time; since the full size is un‐
              known before the transfer starts, such data is sent as chunks by
              HTTP and rejected by IMAP.

              Example: send an image to an HTTP server, where 'profile' is the
              name of the form-field to which the file  portrait.jpg  will  be
              the input:

               curl -F [email protected] https://example.com/upload.cgi

              Example:  send your name and shoe size in two text fields to the
              server:

               curl -F name=John -F shoesize=11 https://example.com/

              Example: send your essay in a text field to the server. Send  it
              as  a plain text field, but get the contents for it from a local
              file:

               curl -F "story=<hugefile.txt" https://example.com/

              You can also  tell  curl  what  Content-Type  to  use  by  using
              'type=', in a manner similar to:

               curl -F "[email protected];type=text/html" example.com

              or

               curl -F "name=daniel;type=text/foo" example.com

              You  can  also explicitly change the name field of a file upload
              part by setting filename=, like this:

               curl -F "file=@localfile;filename=nameinpost" example.com

              If filename/path contains ',' or ';', it must be quoted by  dou‐
              ble-quotes like:

               curl -F "file=@\"local,file\";filename=\"name;in;post\"" example.com

              or

               curl -F 'file=@"local,file";filename="name;in;post"' example.com

              Note  that  if  a  filename/path is quoted by double-quotes, any
              double-quote or backslash within the filename must be escaped by
              backslash.

              Quoting  must  also  be  applied to non-file data if it contains
              semicolons, leading/trailing spaces or leading double quotes:

               curl -F 'colors="red; green; blue";type=text/x-myapp' example.com

              You can add custom headers to the  field  by  setting  headers=,
              like

                curl -F "submit=OK;headers=\"X-submit-type: OK\"" example.com

              or

                curl -F "submit=OK;headers=@headerfile" example.com

              The  headers=  keyword may appear more that once and above notes
              about quoting apply. When headers are read from  a  file,  Empty
              lines and lines starting with '#' are comments and ignored; each
              header can be folded by splitting between two words and starting
              the  continuation  line  with a space; embedded carriage-returns
              and trailing spaces are stripped.   Here  is  an  example  of  a
              header file contents:

                # This file contain two headers.
                X-header-1: this is a header

                # The following header is folded.
                X-header-2: this is
                 another header

              To  support  sending  multipart mail messages, the syntax is ex‐
              tended as follows:
              - name can be omitted: the equal sign is the first character  of
              the argument,
              -  if  data  starts with '(', this signals to start a new multi‐
              part: it can be followed by a content type specification.
              - a multipart can be terminated with a '=)' argument.

              Example: the following command sends an SMTP mime email consist‐
              ing in an inline part in two alternative formats: plain text and
              HTML. It attaches a text file:

               curl -F '=(;type=multipart/alternative' \
                    -F '=plain text message' \
                    -F '= <body>HTML message</body>;type=text/html' \
                    -F '=)' -F '[email protected]' ...  smtp://example.com

              Data can be encoded for transfer using encoder=.  Available  en‐
              codings are binary and 8bit that do nothing else than adding the
              corresponding Content-Transfer-Encoding header, 7bit  that  only
              rejects 8-bit characters with a transfer error, quoted-printable
              and base64 that encodes  data  according  to  the  corresponding
              schemes, limiting lines length to 76 characters.

              Example:  send  multipart mail with a quoted-printable text mes‐
              sage and a base64 attached file:

               curl -F '=text message;encoder=quoted-printable' \
                    -F '=@localfile;encoder=base64' ... smtp://example.com

              See further examples and details in the MANUAL.

              This option can be used multiple times.

              Example:
               curl --form "name=curl" --form "file=@loadthis" https://example.com

              See also -d, --data, --form-string and --form-escape.  This  op‐
              tion overrides -d, --data and -I, --head and -T, --upload-file.

       --ftp-account <data>
              (FTP) When an FTP server asks for "account data" after user name
              and password has been provided, this data is sent off using  the
              ACCT command.

              If this option is used several times, the last one will be used.

              Example:
               curl --ftp-account "mr.robot" ftp://example.com/

              See also -u, --user.

       --ftp-alternative-to-user <command>
              (FTP)  If  authenticating with the USER and PASS commands fails,
              send this  command.   When  connecting  to  Tumbleweed's  Secure
              Transport  server  over  FTPS  using a client certificate, using
              "SITE AUTH" will tell the server to retrieve the  username  from
              the certificate.

              Example:
               curl --ftp-alternative-to-user "U53r" ftp://example.com

              See also --ftp-account and -u, --user.

       --ftp-create-dirs
              (FTP  SFTP)  When  an FTP or SFTP URL/operation uses a path that
              does not currently exist on the server, the standard behavior of
              curl is to fail. Using this option, curl will instead attempt to
              create missing directories.

              Example:
               curl --ftp-create-dirs -T file ftp://example.com/remote/path/file

              See also --create-dirs.

       --ftp-method <method>
              (FTP) Control what method curl should use to reach a file on  an
              FTP(S)  server. The method argument should be one of the follow‐
              ing alternatives:

              multicwd
                     curl does a single CWD operation for each  path  part  in
                     the  given URL. For deep hierarchies this means many com‐
                     mands. This is how RFC 1738 says it should be done.  This
                     is the default but the slowest behavior.

              nocwd  curl  does  no  CWD at all. curl will do SIZE, RETR, STOR
                     etc and give a full path to the server for all these com‐
                     mands. This is the fastest behavior.

              singlecwd
                     curl does one CWD with the full target directory and then
                     operates on the file "normally"  (like  in  the  multicwd
                     case).  This  is  somewhat  more standards compliant than
                     'nocwd' but without the full penalty of 'multicwd'.

       Examples:
        curl --ftp-method multicwd ftp://example.com/dir1/dir2/file
        curl --ftp-method nocwd ftp://example.com/dir1/dir2/file
        curl --ftp-method singlecwd ftp://example.com/dir1/dir2/file

       See also -l, --list-only.

       --ftp-pasv
              (FTP) Use passive mode for the data connection. Passive  is  the
              internal  default behavior, but using this option can be used to
              override a previous -P, --ftp-port option.

              If this option is used several times,  only  the  first  one  is
              used.  Undoing  an enforced passive really is not doable but you
              must then instead enforce the correct -P, --ftp-port again.

              Passive mode means that curl will try the EPSV command first and
              then PASV, unless --disable-epsv is used.

              Example:
               curl --ftp-pasv ftp://example.com/

              See also --disable-epsv.

       -P, --ftp-port <address>
              (FTP)  Reverses  the  default initiator/listener roles when con‐
              necting with FTP. This option makes curl use active  mode.  curl
              then  tells the server to connect back to the client's specified
              address and port, while passive mode asks the server to setup an
              IP  address  and  port for it to connect to. <address> should be
              one of:

              interface
                     e.g. "eth0" to specify which interface's IP  address  you
                     want to use (Unix only)

              IP address
                     e.g. "192.168.10.1" to specify the exact IP address

              host name
                     e.g. "my.host.domain" to specify the machine

              -      make  curl  pick the same IP address that is already used
                     for the control connection

       If this option is used several times, the last one will be  used.  Dis‐
       able  the  use  of PORT with --ftp-pasv. Disable the attempt to use the
       EPRT command instead of PORT by using --disable-eprt.  EPRT  is  really
       PORT++.

       You  can  also  append ":[start]-[end]" to the right of the address, to
       tell curl what TCP port range to use. That means  you  specify  a  port
       range,  from a lower to a higher number. A single number works as well,
       but do note that it increases the risk of failure since  the  port  may
       not be available.

       Examples:
        curl -P - ftp:/example.com
        curl -P eth0 ftp:/example.com
        curl -P 192.168.0.2 ftp:/example.com

       See also --ftp-pasv and --disable-eprt.

       --ftp-pret
              (FTP)  Tell  curl to send a PRET command before PASV (and EPSV).
              Certain FTP servers, mainly drftpd,  require  this  non-standard
              command  for  directory  listings as well as up and downloads in
              PASV mode.

              Example:
               curl --ftp-pret ftp://example.com/

              See also -P, --ftp-port and --ftp-pasv.

       --ftp-skip-pasv-ip
              (FTP) Tell curl to not use the IP address the server suggests in
              its  response to curl's PASV command when curl connects the data
              connection. Instead curl will re-use the same IP address it  al‐
              ready uses for the control connection.

              Since curl 7.74.0 this option is enabled by default.

              This  option has no effect if PORT, EPRT or EPSV is used instead
              of PASV.

              Example:
               curl --ftp-skip-pasv-ip ftp://example.com/

              See also --ftp-pasv.

       --ftp-ssl-ccc-mode <active/passive>
              (FTP) Sets the CCC mode. The passive mode will not initiate  the
              shutdown, but instead wait for the server to do it, and will not
              reply to the shutdown from the server. The active mode initiates
              the shutdown and waits for a reply from the server.

              Example:
               curl --ftp-ssl-ccc-mode active --ftp-ssl-ccc ftps://example.com/

              See also --ftp-ssl-ccc.

       --ftp-ssl-ccc
              (FTP)  Use  CCC  (Clear  Command Channel) Shuts down the SSL/TLS
              layer after authenticating. The rest of the control channel com‐
              munication  will be unencrypted. This allows NAT routers to fol‐
              low the FTP transaction. The default mode is passive.

              Example:
               curl --ftp-ssl-ccc ftps://example.com/

              See also --ssl and --ftp-ssl-ccc-mode.

       --ftp-ssl-control
              (FTP) Require SSL/TLS for the FTP  login,  clear  for  transfer.
              Allows  secure  authentication, but non-encrypted data transfers
              for efficiency.  Fails the transfer if the server does not  sup‐
              port SSL/TLS.

              Example:
               curl --ftp-ssl-control ftp://example.com

              See also --ssl.

       -G, --get
              When  used,  this  option  will make all data specified with -d,
              --data, --data-binary or --data-urlencode to be used in an  HTTP
              GET  request instead of the POST request that otherwise would be
              used. The data will be appended to the URL with a '?' separator.

              If used in combination with -I, --head, the POST data  will  in‐
              stead be appended to the URL with a HEAD request.

              If  this  option  is  used  several times, only the first one is
              used. This is because undoing a GET does not make sense, but you
              should then instead enforce the alternative method you prefer.

              Examples:
               curl --get https://example.com
               curl --get -d "tool=curl" -d "age=old" https://example.com
               curl --get -I -d "tool=curl" https://example.com

              See also -d, --data and -X, --request.

       -g, --globoff
              This option switches off the "URL globbing parser". When you set
              this option, you can specify URLs that contain the letters  {
    
    }[]
              without  having curl itself interpret them. Note that these let‐
              ters are not normal legal URL contents but they  should  be  en‐
              coded according to the URI standard.

              Example:
               curl -g "https://example.com/{[]}}}}"

              See also -K, --config and -q, --disable.

       --happy-eyeballs-timeout-ms <milliseconds>
              Happy  Eyeballs is an algorithm that attempts to connect to both
              IPv4 and IPv6 addresses for  dual-stack  hosts,  giving  IPv6  a
              head-start  of the specified number of milliseconds. If the IPv6
              address cannot be connected to within that time, then a  connec‐
              tion  attempt is made to the IPv4 address in parallel. The first
              connection to be established is the one that is used.

              The range of suggested useful values is limited. Happy  Eyeballs
              RFC  6555  says  "It  is RECOMMENDED that connection attempts be
              paced 150-250 ms apart to balance human factors against  network
              load."  libcurl currently defaults to 200 ms. Firefox and Chrome
              currently default to 300 ms.

              If this option is used several times, the last one will be used.

              Example:
               curl --happy-eyeballs-timeout-ms 500 https://example.com

              See also -m, --max-time and --connect-timeout. Added in 7.59.0.

       --haproxy-protocol
              (HTTP) Send a HAProxy PROXY protocol v1 header at the  beginning
              of  the  connection. This is used by some load balancers and re‐
              verse proxies to indicate the client's true IP address and port.

              This option is primarily useful when sending test requests to  a
              service that expects this header.

              Example:
               curl --haproxy-protocol https://example.com

              See also -x, --proxy. Added in 7.60.0.

       -I, --head
              (HTTP FTP FILE) Fetch the headers only! HTTP-servers feature the
              command HEAD which this uses to get nothing but the header of  a
              document.  When  used  on an FTP or FILE file, curl displays the
              file size and last modification time only.

              Example:
               curl -I https://example.com

              See also -G, --get, -v, --verbose and --trace-ascii.

       -H, --header <header/@file>
              (HTTP) Extra header to include in the request when sending  HTTP
              to  a  server. You may specify any number of extra headers. Note
              that if you should add a custom header that has the same name as
              one  of  the  internal  ones curl would use, your externally set
              header will be used instead of the internal one. This allows you
              to  make  even  trickier  stuff than curl would normally do. You
              should not replace internally set headers without  knowing  per‐
              fectly  well  what  you  are doing. Remove an internal header by
              giving a replacement without content on the right  side  of  the
              colon, as in: -H "Host:". If you send the custom header with no-
              value then its header must be terminated with a semicolon,  such
              as -H "X-Custom-Header;" to send "X-Custom-Header:".

              curl  will  make  sure  that each header you add/replace is sent
              with the proper end-of-line marker, you should thus not add that
              as a part of the header content: do not add newlines or carriage
              returns, they will only mess things up for you.

              This option can take an argument in @filename style, which  then
              adds  a  header  for  each line in the input file. Using @- will
              make curl read the header file from stdin. Added in 7.55.0.

              You need --proxy-header to send custom headers  intended  for  a
              HTTP proxy. Added in 7.37.0.

              Passing  on  a  "Transfer-Encoding: chunked" header when doing a
              HTTP request with a request body, will make curl send  the  data
              using chunked encoding.

              WARNING:  headers  set  with  this option will be set in all re‐
              quests - even after redirects are followed, like when told  with
              -L,  --location. This can lead to the header being sent to other
              hosts than the original host, so  sensitive  headers  should  be
              used with caution combined with following redirects.

              This  option  can  be  used multiple times to add/replace/remove
              multiple headers.

              Examples:
               curl -H "X-First-Name: Joe" https://example.com
               curl -H "User-Agent: yes-please/2000" https://example.com
               curl -H "Host:" https://example.com

              See also -A, --user-agent and -e, --referer.

       -h, --help <category>
              Usage help. This lists all commands of the  <category>.   If  no
              arg  was  provided, curl will display the most important command
              line arguments.  If the argument "all" was provided,  curl  will
              display  all  options available.  If the argument "category" was
              provided, curl will display all categories and their meanings.

              Example:
               curl --help all

              See also -v, --verbose.

       --hostpubmd5 <md5>
              (SFTP SCP) Pass a string containing 32 hexadecimal  digits.  The
              string  should  be the 128 bit MD5 checksum of the remote host's
              public key, curl will refuse the connection with the host unless
              the md5sums match.

              Example:
               curl --hostpubmd5 e5c1c49020640a5ab0f2034854c321a8 sftp://example.com/

              See also --hostpubsha256.

       --hostpubsha256 <sha256>
              (SFTP SCP) Pass a string containing a Base64-encoded SHA256 hash
              of the remote host's public key. Curl will refuse the connection
              with the host unless the hashes match.

              Example:
               curl --hostpubsha256 NDVkMTQxMGQ1ODdmMjQ3MjczYjAyOTY5MmRkMjVmNDQ= sftp://example.com/

              See also --hostpubmd5. Added in 7.80.0.

       --hsts <file name>
              (HTTPS)  This  option enables HSTS for the transfer. If the file
              name points to an existing HSTS cache file, that will  be  used.
              After  a completed transfer, the cache will be saved to the file
              name again if it has been modified.

              Specify a "" file name (zero length) to avoid loading/saving and
              make curl just handle HSTS in memory.

              If  this  option  is used several times, curl will load contents
              from all the files but the last one will be used for saving.

              Example:
               curl --hsts cache.txt https://example.com

              See also --proto. Added in 7.74.0.

       --http0.9
              (HTTP) Tells curl to be fine with HTTP version 0.9 response.

              HTTP/0.9 is a completely headerless response and  therefore  you
              can  also  connect with this to non-HTTP servers and still get a
              response since curl will simply transparently downgrade - if al‐
              lowed.

              Since curl 7.66.0, HTTP/0.9 is disabled by default.

              Example:
               curl --http0.9 https://example.com

              See also --http1.1, --http2 and --http3. Added in 7.64.0.

       -0, --http1.0
              (HTTP)  Tells  curl to use HTTP version 1.0 instead of using its
              internally preferred HTTP version.

              Example:
               curl --http1.0 https://example.com

              See  also  --http0.9  and  --http1.1.  This   option   overrides
              --http1.1 and --http2.

       --http1.1
              (HTTP) Tells curl to use HTTP version 1.1.

              Example:
               curl --http1.1 https://example.com

              See  also  --http1.1  and  --http0.9.  This option overrides -0,
              --http1.0 and --http2. Added in 7.33.0.

       --http2-prior-knowledge
              (HTTP) Tells curl to  issue  its  non-TLS  HTTP  requests  using
              HTTP/2  without  HTTP/1.1  Upgrade.  It requires prior knowledge
              that the server supports HTTP/2 straight  away.  HTTPS  requests
              will  still  do HTTP/2 the standard way with negotiated protocol
              version in the TLS handshake.

              Example:
               curl --http2-prior-knowledge https://example.com

              See also --http2 and --http3.  --http2-prior-knowledge  requires
              that  the  underlying  libcurl was built to support HTTP/2. This
              option overrides --http1.1 and -0, --http1.0 and --http2.  Added
              in 7.49.0.

       --http2
              (HTTP) Tells curl to use HTTP version 2.

              For  HTTPS,  this means curl will attempt to negotiate HTTP/2 in
              the TLS handshake. curl does this by default.

              For HTTP, this means curl will attempt to upgrade the request to
              HTTP/2 using the Upgrade: request header.

              Example:
               curl --http2 https://example.com

              See also --http1.1 and --http3. --http2 requires that the under‐
              lying libcurl was built to support HTTP/2. This option overrides
              --http1.1  and  -0, --http1.0 and --http2-prior-knowledge. Added
              in 7.33.0.

       --http3
              (HTTP) WARNING: this option is experimental. Do not use in  pro‐
              duction.

              Tells  curl  to use HTTP version 3 directly to the host and port
              number used in the URL. A normal HTTP/3 transaction will be done
              to  a  host and then get redirected via Alt-Svc, but this option
              allows a user to circumvent that when you know that  the  target
              speaks HTTP/3 on the given host and port.

              This  option  will make curl fail if a QUIC connection cannot be
              established, it cannot fall back to a lower HTTP version on  its
              own.

              Example:
               curl --http3 https://example.com

              See also --http1.1 and --http2. --http3 requires that the under‐
              lying libcurl was built to support HTTP/3. This option overrides
              --http1.1 and -0, --http1.0 and --http2 and --http2-prior-knowl‐
              edge. Added in 7.66.0.

       --ignore-content-length
              (FTP HTTP) For HTTP, Ignore the Content-Length header.  This  is
              particularly  useful  for servers running Apache 1.x, which will
              report incorrect Content-Length for files larger  than  2  giga‐
              bytes.

              For  FTP (since 7.46.0), skip the RETR command to figure out the
              size before downloading a file.

              This option does not work for HTTP if libcurl was built  to  use
              hyper.

              Example:
               curl --ignore-content-length https://example.com

              See also --ftp-skip-pasv-ip.

       -i, --include
              Include  the  HTTP  response headers in the output. The HTTP re‐
              sponse headers can include things  like  server  name,  cookies,
              date of the document, HTTP version and more...

              To view the request headers, consider the -v, --verbose option.

              Example:
               curl -i https://example.com

              See also -v, --verbose.

       -k, --insecure
              (TLS SFTP SCP) By default, every secure connection curl makes is
              verified to be secure before the transfer takes place. This  op‐
              tion  makes  curl skip the verification step and proceed without
              checking.

              When this option is not used for protocols using TLS, curl veri‐
              fies  the server's TLS certificate before it continues: that the
              certificate contains the right name which matches the host  name
              used in the URL and that the certificate has been signed by a CA
              certificate present in the cert store.  See this online resource
              for further details:
               https://curl.se/docs/sslcerts.html

              For  SFTP  and  SCP, this option makes curl skip the known_hosts
              verification.  known_hosts is a  file  normally  stored  in  the
              user's  home  directory in the .ssh subdirectory, which contains
              host names and their public keys.

              WARNING: using this option makes the transfer insecure.

              Example:
               curl --insecure https://example.com

              See also --proxy-insecure, --cacert and --capath.

       --interface <name>
              Perform an operation using a specified interface. You can  enter
              interface  name,  IP address or host name. An example could look
              like:

               curl --interface eth0:1 https://www.example.com/

              If this option is used several times, the last one will be used.

              On Linux it can be used to specify a VRF, but the  binary  needs
              to  either  have CAP_NET_RAW or to be run as root. More informa‐
              tion  about  Linux  VRF:   https://www.kernel.org/doc/Documenta‐
              tion/networking/vrf.txt

              Example:
               curl --interface eth0 https://example.com

              See also --dns-interface.

       -4, --ipv4
              This  option tells curl to resolve names to IPv4 addresses only,
              and not for example try IPv6.

              Example:
               curl --ipv4 https://example.com

              See also  --http1.1  and  --http2.  This  option  overrides  -6,
              --ipv6.

       -6, --ipv6
              This  option tells curl to resolve names to IPv6 addresses only,
              and not for example try IPv4.

              Example:
               curl --ipv6 https://example.com

              See also  --http1.1  and  --http2.  This  option  overrides  -4,
              --ipv4.

       -j, --junk-session-cookies
              (HTTP) When curl is told to read cookies from a given file, this
              option will make it discard all "session cookies". This will ba‐
              sically  have  the  same  effect as if a new session is started.
              Typical browsers always discard session cookies  when  they  are
              closed down.

              Example:
               curl --junk-session-cookies -b cookies.txt https://example.com

              See also -b, --cookie and -c, --cookie-jar.

       --keepalive-time <seconds>
              This  option sets the time a connection needs to remain idle be‐
              fore sending keepalive probes and the  time  between  individual
              keepalive probes. It is currently effective on operating systems
              offering  the  TCP_KEEPIDLE  and  TCP_KEEPINTVL  socket  options
              (meaning  Linux, recent AIX, HP-UX and more). This option has no
              effect if --no-keepalive is used.

              If this option is used several times, the last one will be used.
              If unspecified, the option defaults to 60 seconds.

              Example:
               curl --keepalive-time 20 https://example.com

              See also --no-keepalive and -m, --max-time.

       --key-type <type>
              (TLS)  Private key file type. Specify which type your --key pro‐
              vided private key is. DER, PEM, and ENG are  supported.  If  not
              specified, PEM is assumed.

              If this option is used several times, the last one will be used.

              Example:
               curl --key-type DER --key here https://example.com

              See also --key.

       --key <key>
              (TLS SSH) Private key file name. Allows you to provide your pri‐
              vate key in this separate file. For SSH, if not specified,  curl
              tries   the  following  candidates  in  order:  '~/.ssh/id_rsa',
              '~/.ssh/id_dsa', './id_rsa', './id_dsa'.

              If curl is built against OpenSSL library, and the engine  pkcs11
              is available, then a PKCS#11 URI (RFC 7512) can be used to spec‐
              ify a private key located in a PKCS#11 device. A  string  begin‐
              ning  with  "pkcs11:" will be interpreted as a PKCS#11 URI. If a
              PKCS#11 URI is provided, then the --engine option will be set as
              "pkcs11"  if none was provided and the --key-type option will be
              set as "ENG" if none was provided.

              If this option is used several times, the last one will be used.

              Example:
               curl --cert certificate --key here https://example.com

              See also --key-type and -E, --cert.

       --krb <level>
              (FTP) Enable Kerberos authentication and use. The level must  be
              entered and should be one of 'clear', 'safe', 'confidential', or
              'private'. Should you use a level that  is  not  one  of  these,
              'private' will instead be used.

              If this option is used several times, the last one will be used.

              Example:
               curl --krb clear ftp://example.com/

              See  also --delegation and --ssl. --krb requires that the under‐
              lying libcurl was built to support Kerberos.

       --libcurl <file>
              Append this option to any ordinary curl command  line,  and  you
              will  get  libcurl-using  C source code written to the file that
              does the equivalent of what your command-line operation does!

              This option is global and does not need to be specified for each
              use of -:, --next.

              If  this  option is used several times, the last given file name
              will be used.

              Example:
               curl --libcurl client.c https://example.com

              See also -v, --verbose.

       --limit-rate <speed>
              Specify the maximum transfer rate you want curl  to  use  -  for
              both downloads and uploads. This feature is useful if you have a
              limited pipe and you would like your transfer not  to  use  your
              entire bandwidth. To make it slower than it otherwise would be.

              The  given speed is measured in bytes/second, unless a suffix is
              appended.  Appending 'k' or 'K' will count the number  as  kilo‐
              bytes,  'm' or 'M' makes it megabytes, while 'g' or 'G' makes it
              gigabytes. The suffixes (k, M, G, T, P) are 1024 based. For  ex‐
              ample 1k is 1024. Examples: 200K, 3m and 1G.

              The rate limiting logic works on averaging the transfer speed to
              no more than the set threshold over a period  of  multiple  sec‐
              onds.

              If  you  also use the -Y, --speed-limit option, that option will
              take precedence and might cripple the rate-limiting slightly, to
              help keeping the speed-limit logic working.

              If this option is used several times, the last one will be used.

              Examples:
               curl --limit-rate 100K https://example.com
               curl --limit-rate 1000 https://example.com
               curl --limit-rate 10M https://example.com

              See also -Y, --speed-limit and -y, --speed-time.

       -l, --list-only
              (FTP  POP3)  (FTP)  When  listing  an FTP directory, this switch
              forces a name-only view. This is especially useful if  the  user
              wants  to  machine-parse  the contents of an FTP directory since
              the normal directory view does not use a standard look  or  for‐
              mat.  When  used like this, the option causes an NLST command to
              be sent to the server instead of LIST.

              Note: Some FTP servers list only  files  in  their  response  to
              NLST; they do not include sub-directories and symbolic links.

              (POP3)  When  retrieving a specific email from POP3, this switch
              forces a LIST command to be performed instead of RETR.  This  is
              particularly  useful if the user wants to see if a specific mes‐
              sage-id exists on the server and what size it is.

              Note: When combined with -X, --request, this option can be  used
              to  send a UIDL command instead, so the user may use the email's
              unique identifier rather than its message-id  to  make  the  re‐
              quest.

              Example:
               curl --list-only ftp://example.com/dir/

              See also -Q, --quote and -X, --request.

       --local-port <num/range>
              Set  a  preferred single number or range (FROM-TO) of local port
              numbers to use for the connection(s).  Note that port numbers by
              nature  are a scarce resource that will be busy at times so set‐
              ting this range to something too narrow might cause  unnecessary
              connection setup failures.

              Example:
               curl --local-port 1000-3000 https://example.com

              See also -g, --globoff.

       --location-trusted
              (HTTP)  Like  -L,  --location, but will allow sending the name +
              password to all hosts that the site may redirect to. This may or
              may not introduce a security breach if the site redirects you to
              a site to which you will send your authentication info (which is
              plaintext in the case of HTTP Basic authentication).

              Example:
               curl --location-trusted -u user:password https://example.com

              See also -u, --user.

       -L, --location
              (HTTP)  If  the server reports that the requested page has moved
              to a different location (indicated with a Location: header and a
              3XX  response code), this option will make curl redo the request
              on the new place. If used together with  -i,  --include  or  -I,
              --head, headers from all requested pages will be shown. When au‐
              thentication is used, curl only sends  its  credentials  to  the
              initial  host.  If a redirect takes curl to a different host, it
              will not be able to intercept the user+password. See also  --lo‐
              cation-trusted  on  how to change this. You can limit the amount
              of redirects to follow by using the --max-redirs option.

              When curl follows a redirect and if the request is  a  POST,  it
              will  send the following request with a GET if the HTTP response
              was 301, 302, or 303. If the response code  was  any  other  3xx
              code, curl will re-send the following request using the same un‐
              modified method.

              You can tell curl to not change POST requests to GET after a 30x
              response  by  using  the  dedicated options for that: --post301,
              --post302 and --post303.

              The method set with -X,  --request  overrides  the  method  curl
              would otherwise select to use.

              Example:
               curl -L https://example.com

              See also --resolve and --alt-svc.

       --login-options <options>
              (IMAP  POP3 SMTP) Specify the login options to use during server
              authentication.

              You can use login options to specify protocol  specific  options
              that  may  be  used during authentication. At present only IMAP,
              POP3 and SMTP support login options. For more information  about
              login  options  please  see  RFC  2384,  RFC 5092 and IETF draft
              draft-earhart-url-smtp-00.txt

              If this option is used several times, the last one will be used.

              Example:
               curl --login-options 'AUTH=*' imap://example.com

              See also -u, --user. Added in 7.34.0.

       --mail-auth <address>
              (SMTP) Specify a single address. This will be  used  to  specify
              the  authentication  address  (identity)  of a submitted message
              that is being relayed to another server.

              Example:
               curl --mail-auth [email protected] -T mail smtp://example.com/

              See also --mail-rcpt and --mail-from.

       --mail-from <address>
              (SMTP) Specify a single address that the given mail  should  get
              sent from.

              Example:
               curl --mail-from [email protected] -T mail smtp://example.com/

              See also --mail-rcpt and --mail-auth.

       --mail-rcpt-allowfails
              (SMTP) When sending data to multiple recipients, by default curl
              will abort SMTP conversation if at least one of  the  recipients
              causes RCPT TO command to return an error.

              The  default  behavior can be changed by passing --mail-rcpt-al‐
              lowfails command-line option which will make curl ignore  errors
              and proceed with the remaining valid recipients.

              If  all  recipients  trigger  RCPT  TO failures and this flag is
              specified, curl will still abort the SMTP conversation  and  re‐
              turn the error received from to the last RCPT TO command.

              Example:
               curl --mail-rcpt-allowfails --mail-rcpt [email protected] smtp://example.com

              See also --mail-rcpt. Added in 7.69.0.

       --mail-rcpt <address>
              (SMTP) Specify a single email address, user name or mailing list
              name. Repeat this option several times to send to  multiple  re‐
              cipients.

              When  performing an address verification (VRFY command), the re‐
              cipient should be specified as the user name or  user  name  and
              domain (as per Section 3.5 of RFC5321). (Added in 7.34.0)

              When performing a mailing list expand (EXPN command), the recip‐
              ient should be specified using the mailing list  name,  such  as
              "Friends" or "London-Office".  (Added in 7.34.0)

              Example:
               curl --mail-rcpt [email protected] smtp://example.com

              See also --mail-rcpt-allowfails.

       -M, --manual
              Manual. Display the huge help text.

              Example:
               curl --manual

              See also -v, --verbose, --libcurl and --trace.

       --max-filesize <bytes>
              (FTP HTTP MQTT) Specify the maximum size (in bytes) of a file to
              download. If the file requested is larger than this  value,  the
              transfer will not start and curl will return with exit code 63.

              A  size  modifier may be used. For example, Appending 'k' or 'K'
              will count  the  number  as  kilobytes,  'm'  or  'M'  makes  it
              megabytes,  while 'g' or 'G' makes it gigabytes. Examples: 200K,
              3m and 1G. (Added in 7.58.0)

              NOTE: The file size is not always known prior to  download,  and
              for such files this option has no effect even if the file trans‐
              fer ends up being larger than this given limit.  Example:
               curl --max-filesize 100K https://example.com

              See also --limit-rate.

       --max-redirs <num>
              (HTTP) Set maximum number of redirections to  follow.  When  -L,
              --location  is  used,  to  prevent  curl from following too many
              redirects, by default, the limit is set  to  50  redirects.  Set
              this option to -1 to make it unlimited.

              If this option is used several times, the last one will be used.

              Example:
               curl --max-redirs 3 --location https://example.com

              See also -L, --location.

       -m, --max-time <fractional seconds>
              Maximum  time  in  seconds that you allow the whole operation to
              take.  This is useful for preventing your batch jobs from  hang‐
              ing  for  hours due to slow networks or links going down.  Since
              7.32.0, this option accepts decimal values, but the actual time‐
              out will decrease in accuracy as the specified timeout increases
              in decimal precision.

              If this option is used several times, the last one will be used.

              Examples:
               curl --max-time 10 https://example.com
               curl --max-time 2.92 https://example.com

              See also --connect-timeout.

       --metalink
              This option was previously used to specify a metalink  resource.
              Metalink  support has been disabled in curl since 7.78.0 for se‐
              curity reasons.

              Example:
               curl --metalink file https://example.com

              See also -Z, --parallel.

       --negotiate
              (HTTP) Enables Negotiate (SPNEGO) authentication.

              This option requires a library built with GSS-API or  SSPI  sup‐
              port.  Use  -V,  --version  to  see  if  your curl supports GSS-
              API/SSPI or SPNEGO.

              When using this option, you must also provide a fake -u,  --user
              option  to  activate the authentication code properly. Sending a
              '-u :' is enough as the user name  and  password  from  the  -u,
              --user option are not actually used.

              If  this  option  is  used  several times, only the first one is
              used.

              Example:
               curl --negotiate -u : https://example.com

              See also --basic, --ntlm, --anyauth and --proxy-negotiate.

       --netrc-file <filename>
              This option is similar to -n, --netrc, except that  you  provide
              the  path  (absolute  or  relative)  to the netrc file that curl
              should use. You can only specify one netrc file per  invocation.
              If  several --netrc-file options are provided, the last one will
              be used.

              It will abide by --netrc-optional if specified.

              Example:
               curl --netrc-file netrc https://example.com

              See also -n, --netrc, -u, --user and -K, --config.  This  option
              overrides -n, --netrc.

       --netrc-optional
              Similar  to  -n, --netrc, but this option makes the .netrc usage
              optional and not mandatory as the -n, --netrc option does.

              Example:
               curl --netrc-optional https://example.com

              See also --netrc-file. This option overrides -n, --netrc.

       -n, --netrc
              Makes curl scan the .netrc  (_netrc  on  Windows)  file  in  the
              user's home directory for login name and password. This is typi‐
              cally used for FTP on Unix. If used with HTTP, curl will  enable
              user  authentication. See netrc(5) and ftp(1) for details on the
              file format. Curl will not complain if that file does  not  have
              the  right  permissions  (it should be neither world- nor group-
              readable). The environment variable "HOME" is used to  find  the
              home directory.

              A  quick  and  simple  example of how to setup a .netrc to allow
              curl to FTP to the machine host.domain.com with user  name  'my‐
              self' and password 'secret' could look similar to:

               machine host.domain.com
               login myself
               password secret"

              Example:
               curl --netrc https://example.com

              See also --netrc-file, -K, --config and -u, --user.

       -:, --next
              Tells curl to use a separate operation for the following URL and
              associated options. This allows you  to  send  several  URL  re‐
              quests,  each with their own specific options, for example, such
              as different user names or custom requests for each.

              -:, --next will reset all local options  and  only  global  ones
              will  have  their values survive over to the operation following
              the -:, --next instruction. Global options  include  -v,  --ver‐
              bose, --trace, --trace-ascii and --fail-early.

              For  example,  you can do both a GET and a POST in a single com‐
              mand line:

               curl www1.example.com --next -d postthis www2.example.com

              Examples:
               curl https://example.com --next -d postthis www2.example.com
               curl -I https://example.com --next https://example.net/

              See also -Z, --parallel and -K, --config. Added in 7.36.0.

       --no-alpn
              (HTTPS) Disable the ALPN TLS extension. ALPN is enabled  by  de‐
              fault  if  libcurl  was  built with an SSL library that supports
              ALPN. ALPN is used by a libcurl that supports HTTP/2 to  negoti‐
              ate HTTP/2 support with the server during https sessions.

              Example:
               curl --no-alpn https://example.com

              See  also  --no-npn and --http2. --no-alpn requires that the un‐
              derlying libcurl was built to support TLS. Added in 7.36.0.

       -N, --no-buffer
              Disables the buffering of the output stream. In normal work sit‐
              uations,  curl  will  use a standard buffered output stream that
              will have the effect that it will output the data in chunks, not
              necessarily  exactly  when  the data arrives.  Using this option
              will disable that buffering.

              Note that this is the negated option name  documented.  You  can
              thus use --buffer to enforce the buffering.

              Example:
               curl --no-buffer https://example.com

              See also -#, --progress-bar.

       --no-keepalive
              Disables  the  use  of keepalive messages on the TCP connection.
              curl otherwise enables them by default.

              Note that this is the negated option name  documented.  You  can
              thus use --keepalive to enforce keepalive.

              Example:
               curl --no-keepalive https://example.com

              See also --keepalive-time.

       --no-npn
              (HTTPS) Disable the NPN TLS extension. NPN is enabled by default
              if libcurl was built with an SSL library that supports NPN.  NPN
              is  used  by  a libcurl that supports HTTP/2 to negotiate HTTP/2
              support with the server during https sessions.

              Example:
               curl --no-npn https://example.com

              See also --no-alpn and --http2. --no-npn requires that  the  un‐
              derlying libcurl was built to support TLS. Added in 7.36.0.

       --no-progress-meter
              Option to switch off the progress meter output without muting or
              otherwise affecting warning and informational messages like  -s,
              --silent does.

              Note  that  this  is the negated option name documented. You can
              thus use --progress-meter to enable the progress meter again.

              Example:
               curl --no-progress-meter -o store https://example.com

              See also -v, --verbose and -s, --silent. Added in 7.67.0.

       --no-sessionid
              (TLS) Disable curl's use of SSL session-ID caching.  By  default
              all  transfers are done using the cache. Note that while nothing
              should ever get hurt by attempting  to  reuse  SSL  session-IDs,
              there seem to be broken SSL implementations in the wild that may
              require you to disable this in order for you to succeed.

              Note that this is the negated option name  documented.  You  can
              thus use --sessionid to enforce session-ID caching.

              Example:
               curl --no-sessionid https://example.com

              See also -k, --insecure.

       --noproxy <no-proxy-list>
              Comma-separated  list  of hosts for which not to use a proxy, if
              one is specified. The only wildcard is  a  single  *  character,
              which  matches  all  hosts,  and effectively disables the proxy.
              Each name in this list is matched as either a domain which  con‐
              tains  the  hostname,  or  the hostname itself. For example, lo‐
              cal.com would match local.com, local.com:80, and  www.local.com,
              but not www.notlocal.com.

              Since  7.53.0,  This  option overrides the environment variables
              that disable the proxy ('no_proxy' and 'NO_PROXY').  If  there's
              an  environment  variable disabling a proxy, you can set the no‐
              proxy list to "" to override it.

              Example:
               curl --noproxy "www.example" https://example.com

              See also -x, --proxy.

       --ntlm-wb
              (HTTP) Enables NTLM much in the style --ntlm does, but hand over
              the  authentication  to the separate binary ntlmauth application
              that is executed when needed.

              Example:
               curl --ntlm-wb -u user:password https://example.com

              See also --ntlm and --proxy-ntlm.

       --ntlm (HTTP) Enables  NTLM  authentication.  The  NTLM  authentication
              method was designed by Microsoft and is used by IIS web servers.
              It is a proprietary protocol, reverse-engineered by clever  peo‐
              ple and implemented in curl based on their efforts. This kind of
              behavior should not be endorsed, you should  encourage  everyone
              who  uses  NTLM to switch to a public and documented authentica‐
              tion method instead, such as Digest.

              If you want to enable NTLM for your proxy  authentication,  then
              use --proxy-ntlm.

              If  this  option  is  used  several times, only the first one is
              used.

              Example:
               curl --ntlm -u user:password https://example.com

              See also  --proxy-ntlm.  --ntlm  requires  that  the  underlying
              libcurl  was built to support TLS. This option overrides --basic
              and --negotiate and --digest and --anyauth.

       --oauth2-bearer <token>
              (IMAP POP3 SMTP HTTP) Specify the Bearer  Token  for  OAUTH  2.0
              server  authentication.  The Bearer Token is used in conjunction
              with the user name which can be specified as part of  the  --url
              or -u, --user options.

              The  Bearer  Token  and user name are formatted according to RFC
              6750.

              If this option is used several times, the last one will be used.

              Example:
               curl --oauth2-bearer "mF_9.B5f-4.1JqM" https://example.com

              See also --basic, --ntlm and --digest. Added in 7.33.0.

       --output-dir <dir>

              This option specifies the directory in  which  files  should  be
              stored, when -O, --remote-name or -o, --output are used.

              The  given  output directory is used for all URLs and output op‐
              tions on the command line, up until the first -:, --next.

              If the specified target directory does not exist, the  operation
              will fail unless --create-dirs is also used.

              If this option is used multiple times, the last specified direc‐
              tory will be used.

              Example:
               curl --output-dir "tmp" -O https://example.com

              See also -O, --remote-name and -J,  --remote-header-name.  Added
              in 7.73.0.

       -o, --output <file>
              Write output to <file> instead of stdout. If you are using {} or
              [] to fetch multiple documents, you should quote the URL and you
              can  use  '#' followed by a number in the <file> specifier. That
              variable will be replaced with the current string  for  the  URL
              being fetched. Like in:

               curl "http://{one,two}.example.com" -o "file_#1.txt"

              or use several variables like:

               curl "http://{site,host}.host[1-5].com" -o "#1_#2"

              You  may use this option as many times as the number of URLs you
              have. For example, if you specify two URLs on the  same  command
              line, you can use it like this:

                curl -o aa example.com -o bb example.net

              and  the  order  of the -o options and the URLs does not matter,
              just that the first -o is for the first URL and so  on,  so  the
              above command line can also be written as

                curl example.com example.net -o aa -o bb

              See  also  the --create-dirs option to create the local directo‐
              ries dynamically. Specifying the output as '-' (a  single  dash)
              will force the output to be done to stdout.

              To   suppress  response  bodies,  you  can  redirect  output  to
              /dev/null:

                curl example.com -o /dev/null

              Or for Windows use nul:

                curl example.com -o nul

              Examples:
               curl -o file https://example.com
               curl "http://{one,two}.example.com" -o "file_#1.txt"
               curl "http://{site,host}.host[1-5].com" -o "#1_#2"
               curl -o file https://example.com -o file2 https://example.net

              See also -O, --remote-name, --remote-name-all and -J,  --remote-
              header-name.

       --parallel-immediate
              When  doing  parallel  transfers, this option will instruct curl
              that it should rather prefer opening up more connections in par‐
              allel at once rather than waiting to see if new transfers can be
              added as multiplexed streams on another connection.

              This option is global and does not need to be specified for each
              use of -:, --next.

              Example:
               curl --parallel-immediate -Z https://example.com -o file1 https://example.com -o file2

              See also -Z, --parallel and --parallel-max. Added in 7.68.0.

       --parallel-max <num>
              When  asked to do parallel transfers, using -Z, --parallel, this
              option controls the maximum amount of transfers to do simultane‐
              ously.

              This option is global and does not need to be specified for each
              use of -:, --next.

              The default is 50.

              Example:
               curl --parallel-max 100 -Z https://example.com ftp://example.com/

              See also -Z, --parallel. Added in 7.66.0.

       -Z, --parallel
              Makes curl perform its transfers in parallel as compared to  the
              regular serial manner.

              This option is global and does not need to be specified for each
              use of -:, --next.

              Example:
               curl --parallel https://example.com -o file1 https://example.com -o file2

              See also -:, --next and -v, --verbose. Added in 7.66.0.

       --pass <phrase>
              (SSH TLS) Passphrase for the private key.

              If this option is used several times, the last one will be used.

              Example:
               curl --pass secret --key file https://example.com

              See also --key and -u, --user.

       --path-as-is
              Tell curl to not handle sequences of /../ or /./  in  the  given
              URL  path.  Normally curl will squash or merge them according to
              standards but with this option set you tell it not to do that.

              Example:
               curl --path-as-is https://example.com/../../etc/passwd

              See also --request-target. Added in 7.42.0.

       --pinnedpubkey <hashes>
              (TLS) Tells curl to  use  the  specified  public  key  file  (or
              hashes)  to  verify the peer. This can be a path to a file which
              contains a single public key in PEM or DER format, or any number
              of base64 encoded sha256 hashes preceded by 'sha256//' and sepa‐
              rated by ';'.

              When negotiating a TLS or SSL connection,  the  server  sends  a
              certificate  indicating  its identity. A public key is extracted
              from this certificate and if it does not exactly match the  pub‐
              lic  key provided to this option, curl will abort the connection
              before sending or receiving any data.

              PEM/DER support:

              7.39.0: OpenSSL, GnuTLS and GSKit

              7.43.0: NSS and wolfSSL

              7.47.0: mbedtls

              sha256 support:

              7.44.0: OpenSSL, GnuTLS, NSS and wolfSSL

              7.47.0: mbedtls

              Other SSL backends not supported.

              If this option is used several times, the last one will be used.

              Examples:
               curl --pinnedpubkey keyfile https://example.com
               curl --pinnedpubkey 'sha256//ce118b51897f4452dc' https://example.com

              See also --hostpubsha256. Added in 7.39.0.

       --post301
              (HTTP) Tells curl to respect RFC 7231/6.4.2 and not convert POST
              requests into GET requests when following a 301 redirection. The
              non-RFC behavior is ubiquitous in web browsers, so curl does the
              conversion by default to maintain consistency. However, a server
              may require a POST to remain a POST after  such  a  redirection.
              This option is meaningful only when using -L, --location.

              Example:
               curl --post301 --location -d "data" https://example.com

              See also --post302, --post303 and -L, --location.

       --post302
              (HTTP) Tells curl to respect RFC 7231/6.4.3 and not convert POST
              requests into GET requests when following a 302 redirection. The
              non-RFC behavior is ubiquitous in web browsers, so curl does the
              conversion by default to maintain consistency. However, a server
              may  require  a  POST to remain a POST after such a redirection.
              This option is meaningful only when using -L, --location.

              Example:
               curl --post302 --location -d "data" https://example.com

              See also --post301, --post303 and -L, --location.

       --post303
              (HTTP) Tells curl to violate RFC 7231/6.4.4 and not convert POST
              requests  into  GET  requests when following 303 redirections. A
              server may require a POST to remain a POST after a 303 redirect‐
              ion. This option is meaningful only when using -L, --location.

              Example:
               curl --post303 --location -d "data" https://example.com

              See also --post302, --post301 and -L, --location.

       --preproxy [protocol://]host[:port]
              Use  the  specified  SOCKS proxy before connecting to an HTTP or
              HTTPS -x, --proxy. In such a case curl  first  connects  to  the
              SOCKS  proxy  and  then  connects (through SOCKS) to the HTTP or
              HTTPS proxy. Hence pre proxy.

              The pre proxy string should be specified with a protocol:// pre‐
              fix  to  specify  alternative  proxy  protocols.  Use socks4://,
              socks4a://, socks5:// or  socks5h://  to  request  the  specific
              SOCKS  version  to be used. No protocol specified will make curl
              default to SOCKS4.

              If the port number is not specified in the proxy string,  it  is
              assumed to be 1080.

              User and password that might be provided in the proxy string are
              URL decoded by curl. This allows you to pass in special  charac‐
              ters such as @ by using %40 or pass in a colon with %3a.

              If this option is used several times, the last one will be used.

              Example:
               curl --preproxy socks5://proxy.example -x http://http.example https://example.com

              See also -x, --proxy and --socks5. Added in 7.52.0.

       -#, --progress-bar
              Make curl display transfer progress as a simple progress bar in‐
              stead of the standard, more informational, meter.

              This progress bar draws a single line of '#'  characters  across
              the screen and shows a percentage if the transfer size is known.
              For transfers without a known size, there  will  be  space  ship
              (-=o=-)  that  moves back and forth but only while data is being
              transferred, with a set of flying hash sign symbols on top.

              This option is global and does not need to be specified for each
              use of -:, --next.

              Example:
               curl -# -O https://example.com

              See also --styled-output.

       --proto-default <protocol>
              Tells curl to use protocol for any URL missing a scheme name.

              An  unknown  or  unsupported  protocol causes error CURLE_UNSUP‐
              PORTED_PROTOCOL (1).

              This option does not change the default proxy protocol (http).

              Without this option set, curl guesses protocol based on the host
              name, see --url for details.

              Example:
               curl --proto-default https ftp.example.com

              See also --proto and --proto-redir. Added in 7.45.0.

       --proto-redir <protocols>
              Tells  curl to limit what protocols it may use on redirect. Pro‐
              tocols denied by --proto are not overridden by this option.  See
              --proto for how protocols are represented.

              Example, allow only HTTP and HTTPS on redirect:

               curl --proto-redir -all,http,https http://example.com

              By default curl will only allow HTTP, HTTPS, FTP and FTPS on re‐
              direct (since 7.65.2). Specifying all or +all enables all proto‐
              cols on redirects, which is not good for security.

              Example:
               curl --proto-redir =http,https https://example.com

              See also --proto.

       --proto <protocols>
              Tells  curl  to  limit  what protocols it may use for transfers.
              Protocols are evaluated left to right, are comma separated,  and
              are  each  a protocol name or 'all', optionally prefixed by zero
              or more modifiers. Available modifiers are:

              +  Permit this protocol in addition to protocols already permit‐
                 ted (this is the default if no modifier is used).

              -  Deny  this  protocol,  removing it from the list of protocols
                 already permitted.

              =  Permit only this protocol (ignoring the list already  permit‐
                 ted),  though subject to later modification by subsequent en‐
                 tries in the comma separated list.

              For example:

              --proto -ftps  uses the default protocols, but disables ftps

              --proto -all,https,+http
                             only enables http and https

              --proto =http,https
                             also only enables http and https

              Unknown protocols produce a  warning.  This  allows  scripts  to
              safely  rely on being able to disable potentially dangerous pro‐
              tocols, without relying upon support  for  that  protocol  being
              built into curl to avoid an error.

              This option can be used multiple times, in which case the effect
              is the same as concatenating the protocols into one instance  of
              the option.

              Example:
               curl --proto =http,https,sftp https://example.com

              See also --proto-redir and --proto-default.

       --proxy-anyauth
              Tells  curl to pick a suitable authentication method when commu‐
              nicating with the given HTTP proxy. This might  cause  an  extra
              request/response round-trip.

              Example:
               curl --proxy-anyauth --proxy-user user:passwd -x proxy https://example.com

              See also -x, --proxy, --proxy-basic and --proxy-digest.

       --proxy-basic
              Tells  curl  to use HTTP Basic authentication when communicating
              with the given proxy. Use --basic for enabling HTTP Basic with a
              remote  host.  Basic  is  the default authentication method curl
              uses with proxies.

              Example:
               curl --proxy-basic --proxy-user user:passwd -x proxy https://example.com

              See also -x, --proxy, --proxy-anyauth and --proxy-digest.

       --proxy-cacert <file>
              Same as --cacert but used in HTTPS proxy context.

              Example:
               curl --proxy-cacert CA-file.txt -x https://proxy https://example.com

              See also --proxy-capath, --cacert,  --capath  and  -x,  --proxy.
              Added in 7.52.0.

       --proxy-capath <dir>
              Same as --capath but used in HTTPS proxy context.

              Example:
               curl --proxy-capath /local/directory -x https://proxy https://example.com

              See  also  --proxy-cacert,  -x,  --proxy  and --capath. Added in
              7.52.0.

       --proxy-cert-type <type>
              Same as --cert-type but used in HTTPS proxy context.

              Example:
               curl --proxy-cert-type PEM --proxy-cert file -x https://proxy https://example.com

              See also --proxy-cert. Added in 7.52.0.

       --proxy-cert <cert[:passwd]>
              Same as -E, --cert but used in HTTPS proxy context.

              Example:
               curl --proxy-cert file -x https://proxy https://example.com

              See also --proxy-cert-type. Added in 7.52.0.

       --proxy-ciphers <list>
              Same as --ciphers but used in HTTPS proxy context.

              Example:
               curl --proxy-ciphers ECDHE-ECDSA-AES256-CCM8 -x https://proxy https://example.com

              See also --ciphers, --curves and -x, --proxy. Added in 7.52.0.

       --proxy-crlfile <file>
              Same as --crlfile but used in HTTPS proxy context.

              Example:
               curl --proxy-crlfile rejects.txt -x https://proxy https://example.com

              See also --crlfile and -x, --proxy. Added in 7.52.0.

       --proxy-digest
              Tells curl to use HTTP Digest authentication when  communicating
              with the given proxy. Use --digest for enabling HTTP Digest with
              a remote host.

              Example:
               curl --proxy-digest --proxy-user user:passwd -x proxy https://example.com

              See also -x, --proxy, --proxy-anyauth and --proxy-basic.

       --proxy-header <header/@file>
              (HTTP) Extra header to include in the request when sending  HTTP
              to a proxy. You may specify any number of extra headers. This is
              the equivalent option to -H, --header but is for proxy  communi‐
              cation  only  like  in CONNECT requests when you want a separate
              header sent to the proxy to what is sent to  the  actual  remote
              host.

              curl  will  make  sure  that each header you add/replace is sent
              with the proper end-of-line marker, you should thus not add that
              as a part of the header content: do not add newlines or carriage
              returns, they will only mess things up for you.

              Headers specified with this option will not be included  in  re‐
              quests that curl knows will not be sent to a proxy.

              Starting  in  7.55.0, this option can take an argument in @file‐
              name style, which then adds a header for each line in the  input
              file. Using @- will make curl read the header file from stdin.

              This  option  can  be  used multiple times to add/replace/remove
              multiple headers.

              Examples:
               curl --proxy-header "X-First-Name: Joe" -x http://proxy https://example.com
               curl --proxy-header "User-Agent: surprise" -x http://proxy https://example.com
               curl --proxy-header "Host:" -x http://proxy https://example.com

              See also -x, --proxy. Added in 7.37.0.

       --proxy-insecure
              Same as -k, --insecure but used in HTTPS proxy context.

              Example:
               curl --proxy-insecure -x https://proxy https://example.com

              See also -x, --proxy and -k, --insecure. Added in 7.52.0.

       --proxy-key-type <type>
              Same as --key-type but used in HTTPS proxy context.

              Example:
               curl --proxy-key-type DER --proxy-key here -x https://proxy https://example.com

              See also --proxy-key and -x, --proxy. Added in 7.52.0.

       --proxy-key <key>
              Same as --key but used in HTTPS proxy context.

              Example:
               curl --proxy-key here -x https://proxy https://example.com

              See also --proxy-key-type and -x, --proxy. Added in 7.52.0.

       --proxy-negotiate
              Tells curl to use HTTP Negotiate  (SPNEGO)  authentication  when
              communicating with the given proxy. Use --negotiate for enabling
              HTTP Negotiate (SPNEGO) with a remote host.

              Example:
               curl --proxy-negotiate --proxy-user user:passwd -x proxy https://example.com

              See also --proxy-anyauth and --proxy-basic.

       --proxy-ntlm
              Tells curl to use HTTP NTLM  authentication  when  communicating
              with the given proxy. Use --ntlm for enabling NTLM with a remote
              host.

              Example:
               curl --proxy-ntlm --proxy-user user:passwd -x http://proxy https://example.com

              See also --proxy-negotiate and --proxy-anyauth.

       --proxy-pass <phrase>
              Same as --pass but used in HTTPS proxy context.

              Example:
               curl --proxy-pass secret --proxy-key here -x https://proxy https://example.com

              See also -x, --proxy and --proxy-key. Added in 7.52.0.

       --proxy-pinnedpubkey <hashes>
              (TLS) Tells curl to  use  the  specified  public  key  file  (or
              hashes)  to verify the proxy. This can be a path to a file which
              contains a single public key in PEM or DER format, or any number
              of base64 encoded sha256 hashes preceded by 'sha256//' and sepa‐
              rated by ';'.

              When negotiating a TLS or SSL connection,  the  server  sends  a
              certificate  indicating  its identity. A public key is extracted
              from this certificate and if it does not exactly match the  pub‐
              lic  key provided to this option, curl will abort the connection
              before sending or receiving any data.

              If this option is used several times, the last one will be used.

              Examples:
               curl --proxy-pinnedpubkey keyfile https://example.com
               curl --proxy-pinnedpubkey 'sha256//ce118b51897f4452dc' https://example.com

              See also --pinnedpubkey and -x, --proxy. Added in 7.59.0.

       --proxy-service-name <name>
              This option allows you to change the service name for proxy  ne‐
              gotiation.

              Example:
               curl --proxy-service-name "shrubbery" -x proxy https://example.com

              See also --service-name and -x, --proxy. Added in 7.43.0.

       --proxy-ssl-allow-beast
              Same as --ssl-allow-beast but used in HTTPS proxy context.

              Example:
               curl --proxy-ssl-allow-beast -x https://proxy https://example.com

              See also --ssl-allow-beast and -x, --proxy. Added in 7.52.0.

       --proxy-ssl-auto-client-cert
              Same as --ssl-auto-client-cert but used in HTTPS proxy context.

              Example:
               curl --proxy-ssl-auto-client-cert -x https://proxy https://example.com

              See  also  --ssl-auto-client-cert  and  -x,  --proxy.  Added  in
              7.77.0.

       --proxy-tls13-ciphers <ciphersuite list>
              (TLS) Specifies which cipher suites to use in the connection  to
              your HTTPS proxy when it negotiates TLS 1.3. The list of ciphers
              suites must specify valid ciphers. Read up  on  TLS  1.3  cipher
              suite details on this URL:

               https://curl.se/docs/ssl-ciphers.html

              This  option  is  currently  used only when curl is built to use
              OpenSSL 1.1.1 or later. If you are using a different SSL backend
              you  can try setting TLS 1.3 cipher suites by using the --proxy-
              ciphers option.

              If this option is used several times, the last one will be used.

              Example:
               curl --proxy-tls13-ciphers TLS_AES_128_GCM_SHA256 -x proxy https://example.com

              See also --tls13-ciphers and --curves. Added in 7.61.0.

       --proxy-tlsauthtype <type>
              Same as --tlsauthtype but used in HTTPS proxy context.

              Example:
               curl --proxy-tlsauthtype SRP -x https://proxy https://example.com

              See also -x, --proxy and --proxy-tlsuser. Added in 7.52.0.

       --proxy-tlspassword <string>
              Same as --tlspassword but used in HTTPS proxy context.

              Example:
               curl --proxy-tlspassword passwd -x https://proxy https://example.com

              See also -x, --proxy and --proxy-tlsuser. Added in 7.52.0.

       --proxy-tlsuser <name>
              Same as --tlsuser but used in HTTPS proxy context.

              Example:
               curl --proxy-tlsuser smith -x https://proxy https://example.com

              See also -x, --proxy and --proxy-tlspassword. Added in 7.52.0.

       --proxy-tlsv1
              Same as -1, --tlsv1 but used in HTTPS proxy context.

              Example:
               curl --proxy-tlsv1 -x https://proxy https://example.com

              See also -x, --proxy. Added in 7.52.0.

       -U, --proxy-user <user:password>
              Specify the user name and password to use for proxy  authentica‐
              tion.

              If  you use a Windows SSPI-enabled curl binary and do either Ne‐
              gotiate or NTLM authentication then you can tell curl to  select
              the user name and password from your environment by specifying a
              single colon with this option: "-U :".

              On systems where it works, curl will hide the given option argu‐
              ment  from  process listings. This is not enough to protect cre‐
              dentials from possibly getting seen by other users on  the  same
              system  as  they  will  still  be  visible  for  a moment before
              cleared. Such sensitive data should be retrieved from a file in‐
              stead or similar and never used in clear text in a command line.

              If this option is used several times, the last one will be used.

              Example:
               curl --proxy-user name:pwd -x proxy https://example.com

              See also --proxy-pass.

       -x, --proxy [protocol://]host[:port]
              Use the specified proxy.

              The  proxy string can be specified with a protocol:// prefix. No
              protocol specified or http:// will be treated as HTTP proxy. Use
              socks4://, socks4a://, socks5:// or socks5h:// to request a spe‐
              cific SOCKS version to be used.

              HTTPS proxy support via https:// protocol prefix  was  added  in
              7.52.0 for OpenSSL, GnuTLS and NSS.

              Unrecognized  and  unsupported  proxy  protocols  cause an error
              since 7.52.0.  Prior versions may ignore the  protocol  and  use
              http:// instead.

              If  the  port number is not specified in the proxy string, it is
              assumed to be 1080.

              This option overrides existing environment  variables  that  set
              the  proxy  to use. If there's an environment variable setting a
              proxy, you can set proxy to "" to override it.

              All operations that are performed over an HTTP proxy will trans‐
              parently  be  converted  to HTTP. It means that certain protocol
              specific operations might not be available. This is not the case
              if you can tunnel through the proxy, as one with the -p, --prox‐
              ytunnel option.

              User and password that might be provided in the proxy string are
              URL  decoded by curl. This allows you to pass in special charac‐
              ters such as @ by using %40 or pass in a colon with %3a.

              The proxy host can be specified the same way as the proxy  envi‐
              ronment  variables,  including the protocol prefix (http://) and
              the embedded user + password.

              If this option is used several times, the last one will be used.

              Example:
               curl --proxy http://proxy.example https://example.com

              See also --socks5 and --proxy-basic.

       --proxy1.0 <host[:port]>
              Use the specified HTTP 1.0 proxy. If  the  port  number  is  not
              specified, it is assumed at port 1080.

              The  only  difference between this and the HTTP proxy option -x,
              --proxy, is that attempts to use CONNECT through the proxy  will
              specify an HTTP 1.0 protocol instead of the default HTTP 1.1.

              Example:
               curl --proxy1.0 -x http://proxy https://example.com

              See also -x, --proxy, --socks5 and --preproxy.

       -p, --proxytunnel
              When  an  HTTP  proxy is used -x, --proxy, this option will make
              curl tunnel through the proxy. The tunnel approach is made  with
              the  HTTP  proxy CONNECT request and requires that the proxy al‐
              lows direct connect to the remote port number curl wants to tun‐
              nel through to.

              To  suppress  proxy CONNECT response headers when curl is set to
              output headers use --suppress-connect-headers.

              Example:
               curl --proxytunnel -x http://proxy https://example.com

              See also -x, --proxy.

       --pubkey <key>
              (SFTP SCP) Public key file name. Allows you to provide your pub‐
              lic key in this separate file.

              If this option is used several times, the last one will be used.

              (As of 7.39.0, curl attempts to automatically extract the public
              key from the private key file, so passing this option is  gener‐
              ally not required. Note that this public key extraction requires
              libcurl to be linked against a copy of libssh2 1.2.8  or  higher
              that is itself linked against OpenSSL.)

              Example:
               curl --pubkey file.pub sftp://example.com/

              See also --pass.

       -Q, --quote <command>
              (FTP  SFTP)  Send an arbitrary command to the remote FTP or SFTP
              server. Quote commands are sent BEFORE the transfer takes  place
              (just  after  the  initial PWD command in an FTP transfer, to be
              exact). To make commands take place after a successful transfer,
              prefix them with a dash '-'. To make commands be sent after curl
              has changed the working directory, just before the transfer com‐
              mand(s),  prefix  the command with a '+' (this is only supported
              for FTP). You may specify any number of commands.

              By default curl will stop at first failure. To  make  curl  con‐
              tinue  even if the command fails, prefix the command with an as‐
              terisk (*). Otherwise, if the server returns failure for one  of
              the commands, the entire operation will be aborted.

              You  must send syntactically correct FTP commands as RFC 959 de‐
              fines to FTP servers, or one of the  commands  listed  below  to
              SFTP servers.

              This option can be used multiple times.

              SFTP  is a binary protocol. Unlike for FTP, curl interprets SFTP
              quote commands itself before sending them to  the  server.  File
              names may be quoted shell-style to embed spaces or special char‐
              acters. Following is the list of all supported SFTP  quote  com‐
              mands:

              atime date file
                     The  atime  command sets the last access time of the file
                     named by the file operand. The <date expression>  can  be
                     all  sorts  of  date strings, see the curl_getdate(3) man
                     page for date expression details. (Added in 7.73.0)

              chgrp group file
                     The chgrp command sets the group ID of the file named  by
                     the  file  operand to the group ID specified by the group
                     operand. The group operand is a decimal integer group ID.

              chmod mode file
                     The chmod command modifies the  file  mode  bits  of  the
                     specified file. The mode operand is an octal integer mode
                     number.

              chown user file
                     The chown command sets the owner of the file named by the
                     file  operand  to the user ID specified by the user oper‐
                     and. The user operand is a decimal integer user ID.

              ln source_file target_file
                     The ln and symlink commands create a symbolic link at the
                     target_file  location  pointing  to the source_file loca‐
                     tion.

              mkdir directory_name
                     The mkdir command creates the directory named by the  di‐
                     rectory_name operand.

              mtime date file
                     The  mtime command sets the last modification time of the
                     file named by the file operand. The <date expression> can
                     be all sorts of date strings, see the curl_getdate(3) man
                     page for date expression details. (Added in 7.73.0)

              pwd    The pwd command returns the absolute pathname of the cur‐
                     rent working directory.

              rename source target
                     The rename command renames the file or directory named by
                     the source operand to the destination path named  by  the
                     target operand.

              rm file
                     The rm command removes the file specified by the file op‐
                     erand.

              rmdir directory
                     The rmdir command removes the directory  entry  specified
                     by the directory operand, provided it is empty.

              symlink source_file target_file
                     See ln.

       Example:
        curl --quote "DELE file" ftp://example.com/foo

       See also -X, --request.

       --random-file <file>
              Specify the path name to file containing what will be considered
              as random data. The data may be used to seed the  random  engine
              for SSL connections. See also the --egd-file option.

              Example:
               curl --random-file rubbish https://example.com

              See also --egd-file.

       -r, --range <range>
              (HTTP FTP SFTP FILE) Retrieve a byte range (i.e. a partial docu‐
              ment) from an HTTP/1.1, FTP or SFTP  server  or  a  local  FILE.
              Ranges can be specified in a number of ways.

              0-499     specifies the first 500 bytes

              500-999   specifies the second 500 bytes

              -500      specifies the last 500 bytes

              9500-     specifies the bytes from offset 9500 and forward

              0-0,-1    specifies the first and last byte only(*)(HTTP)

              100-199,500-599
                        specifies two separate 100-byte ranges(*) (HTTP)

              (*)  = NOTE that this will cause the server to reply with a mul‐
              tipart response, which will be returned as-is by  curl!  Parsing
              or otherwise transforming this response is the responsibility of
              the caller.

              Only digit characters (0-9) are valid in the 'start' and  'stop'
              fields  of the 'start-stop' range syntax. If a non-digit charac‐
              ter is given in the range, the server's response will be unspec‐
              ified, depending on the server's configuration.

              You  should also be aware that many HTTP/1.1 servers do not have
              this feature enabled, so that when you attempt to get  a  range,
              you will instead get the whole document.

              FTP  and  SFTP  range  downloads only support the simple 'start-
              stop' syntax (optionally with one of the numbers  omitted).  FTP
              use depends on the extended FTP command SIZE.

              If this option is used several times, the last one will be used.

              Example:
               curl --range 22-44 https://example.com

              See also -C, --continue-at and -a, --append.

       --raw  (HTTP) When used, it disables all internal HTTP decoding of con‐
              tent or transfer encodings and instead makes them passed on  un‐
              altered, raw.

              Example:
               curl --raw https://example.com

              See also --tr-encoding.

       -e, --referer <URL>
              (HTTP) Sends the "Referrer Page" information to the HTTP server.
              This can also be set with the -H, --header flag of course.  When
              used  with  -L,  --location  you  can  append ";auto" to the -e,
              --referer URL to make curl automatically set  the  previous  URL
              when  it  follows  a Location: header. The ";auto" string can be
              used alone, even if you do not set an initial -e, --referer.

              If this option is used several times, the last one will be used.

              Examples:
               curl --referer "https://fake.example" https://example.com
               curl --referer "https://fake.example;auto" -L https://example.com
               curl --referer ";auto" -L https://example.com

              See also -A, --user-agent and -H, --header.

       -J, --remote-header-name
              (HTTP) This option tells the -O, --remote-name option to use the
              server-specified  Content-Disposition  filename  instead  of ex‐
              tracting a filename from the URL.

              If the server specifies a file name and a file  with  that  name
              already  exists  in the current working directory it will not be
              overwritten and an error will occur.  If  the  server  does  not
              specify a file name then this option has no effect.

              There's  no  attempt to decode %-sequences (yet) in the provided
              file name, so this option may provide you with rather unexpected
              file names.

              WARNING:  Exercise  judicious  use of this option, especially on
              Windows. A rogue server could send you the  name  of  a  DLL  or
              other file that could be loaded automatically by Windows or some
              third party software.

              Example:
               curl -OJ https://example.com/file

              See also -O, --remote-name.

       --remote-name-all
              This option changes the default action for all given URLs to  be
              dealt with as if -O, --remote-name were used for each one. So if
              you want to disable that for a specific URL after --remote-name-
              all has been used, you must use "-o -" or --no-remote-name.

              Example:
               curl --remote-name-all ftp://example.com/file1 ftp://example.com/file2

              See also -O, --remote-name.

       -O, --remote-name
              Write  output to a local file named like the remote file we get.
              (Only the file part of the remote file is used, the path is  cut
              off.)

              The  file will be saved in the current working directory. If you
              want the file saved in a  different  directory,  make  sure  you
              change  the  current working directory before invoking curl with
              this option.

              The remote file name to use for saving  is  extracted  from  the
              given  URL,  nothing  else,  and if it already exists it will be
              overwritten. If you want the server to be  able  to  choose  the
              file name refer to -J, --remote-header-name which can be used in
              addition to this option. If the server chooses a file  name  and
              that name already exists it will not be overwritten.

              There is no URL decoding done on the file name. If it has %20 or
              other URL encoded parts of the name, they will end up  as-is  as
              file name.

              You  may use this option as many times as the number of URLs you
              have.

              Example:
               curl -O https://example.com/filename

              See also --remote-name-all.

       -R, --remote-time
              When used, this will make curl attempt to figure out  the  time‐
              stamp  of the remote file, and if that is available make the lo‐
              cal file get that same timestamp.

              Example:
               curl --remote-time -o foo https://example.com

              See also -O, --remote-name and -z, --time-cond.

       --request-target <path>
              (HTTP) Tells curl to use an alternative "target" (path)  instead
              of  using  the  path as provided in the URL. Particularly useful
              when wanting to issue HTTP requests  without  leading  slash  or
              other  data  that  does not follow the regular URL pattern, like
              "OPTIONS *".

              Example:
               curl --request-target "*" -X OPTIONS https://example.com

              See also -X, --request. Added in 7.55.0.

       -X, --request <method>
              (HTTP) Specifies a custom request method to use when communicat‐
              ing  with  the HTTP server. The specified request method will be
              used instead of the method otherwise  used  (which  defaults  to
              GET).  Read  the HTTP 1.1 specification for details and explana‐
              tions. Common additional HTTP requests include PUT  and  DELETE,
              but related technologies like WebDAV offers PROPFIND, COPY, MOVE
              and more.

              Normally you do not need this option. All sorts  of  GET,  HEAD,
              POST and PUT requests are rather invoked by using dedicated com‐
              mand line options.

              This option only changes the actual word used in  the  HTTP  re‐
              quest, it does not alter the way curl behaves. So for example if
              you want to make a proper HEAD request, using -X HEAD  will  not
              suffice. You need to use the -I, --head option.

              The  method  string  you set with -X, --request will be used for
              all requests, which if you for example use  -L,  --location  may
              cause  unintended side-effects when curl does not change request
              method according to the HTTP 30x response codes - and similar.

              (FTP) Specifies a custom FTP command to use instead of LIST when
              doing file lists with FTP.

              (POP3) Specifies a custom POP3 command to use instead of LIST or
              RETR.

              (IMAP) Specifies a custom IMAP command to use instead  of  LIST.
              (Added in 7.30.0)

              (SMTP) Specifies a custom SMTP command to use instead of HELP or
              VRFY. (Added in 7.34.0)

              If this option is used several times, the last one will be used.

              Examples:
               curl -X "DELETE" https://example.com
               curl -X NLST ftp://example.com/

              See also --request-target.

       --resolve <[+]host:port:addr[,addr]...>
              Provide a custom address for a specific host and port pair.  Us‐
              ing  this, you can make the curl requests(s) use a specified ad‐
              dress and prevent the otherwise normally resolved address to  be
              used.  Consider  it a sort of /etc/hosts alternative provided on
              the command line. The port number should be the number used  for
              the  specific  protocol  the host will be used for. It means you
              need several entries if you want to provide address for the same
              host but different ports.

              By  specifying '*' as host you can tell curl to resolve any host
              and specific port pair to the specified address. Wildcard is re‐
              solved  last so any --resolve with a specific host and port will
              be used first.

              The provided address set by this option will be used even if -4,
              --ipv4 or -6, --ipv6 is set to make curl use another IP version.

              By prefixing the host with a '+' you can make the entry time out
              after curl's default timeout (1 minute).  Note  that  this  will
              only  make  sense for long running parallel transfers with a lot
              of files. In such cases, if this option is used curl will try to
              resolve  the  host as it normally would once the timeout has ex‐
              pired.

              Support for providing the IP address within [brackets] was added
              in 7.57.0.

              Support  for providing multiple IP addresses per entry was added
              in 7.59.0.

              Support for resolving with wildcard was added in 7.64.0.

              Support for the '+' prefix was was added in 7.75.0.

              This option can be used many times to add many host names to re‐
              solve.

              Example:
               curl --resolve example.com:443:127.0.0.1 https://example.com

              See also --connect-to and --alt-svc.

       --retry-all-errors
              Retry on any error. This option is used together with --retry.

              This  option  is the "sledgehammer" of retrying. Do not use this
              option by default (eg in curlrc), there may be unintended conse‐
              quences  such as sending or receiving duplicate data. Do not use
              with redirected input or output. You'd be much better  off  han‐
              dling  your unique problems in shell script. Please read the ex‐
              ample below.

              WARNING: For server compatibility curl attempts to retry  failed
              flaky  transfers  as close as possible to how they were started,
              but this is not possible with redirected input  or  output.  For
              example,  before  retrying  it removes output data from a failed
              partial transfer that was written to  an  output  file.  However
              this is not true of data redirected to a | pipe or > file, which
              are not reset. We strongly suggest you do not  parse  or  record
              output  via  redirect in combination with this option, since you
              may receive duplicate data.

              By default curl will not error on an HTTP response code that in‐
              dicates an HTTP error, if the transfer was successful. For exam‐
              ple, if a server replies 404 Not Found and the  reply  is  fully
              received  then  that  is not an error. When --retry is used then
              curl will retry on some HTTP response codes that indicate  tran‐
              sient  HTTP  errors, but that does not include most 4xx response
              codes such as 404. If you want to retry on  all  response  codes
              that  indicate  HTTP  errors (4xx and 5xx) then combine with -f,
              --fail.

              Example:
               curl --retry 5 --retry-all-errors https://example.com

              See also --retry. Added in 7.71.0.

       --retry-connrefused
              In addition to the other conditions, consider ECONNREFUSED as  a
              transient  error  too  for --retry. This option is used together
              with --retry.

              Example:
               curl --retry-connrefused --retry https://example.com

              See also --retry and --retry-all-errors. Added in 7.52.0.

       --retry-delay <seconds>
              Make curl sleep this amount of time before  each  retry  when  a
              transfer  has  failed with a transient error (it changes the de‐
              fault backoff time algorithm between retries).  This  option  is
              only  interesting if --retry is also used. Setting this delay to
              zero will make curl use the default backoff time.

              If this option is used several times, the last one will be used.

              Example:
               curl --retry-delay 5 --retry https://example.com

              See also --retry.

       --retry-max-time <seconds>
              The retry timer is reset before the first transfer attempt.  Re‐
              tries  will  be done as usual (see --retry) as long as the timer
              has not reached this given limit. Notice that if the  timer  has
              not  reached  the limit, the request will be made and while per‐
              forming, it may take longer than  this  given  time  period.  To
              limit  a  single request's maximum time, use -m, --max-time. Set
              this option to zero to not timeout retries.

              If this option is used several times, the last one will be used.

              Example:
               curl --retry-max-time 30 --retry 10 https://example.com

              See also --retry.

       --retry <num>
              If a transient error is returned when curl tries  to  perform  a
              transfer,  it  will retry this number of times before giving up.
              Setting the number to 0 makes curl do no retries (which  is  the
              default).  Transient  error  means either: a timeout, an FTP 4xx
              response code or an HTTP 408, 429, 500, 502, 503 or 504 response
              code.

              When  curl  is about to retry a transfer, it will first wait one
              second and then for all forthcoming retries it will  double  the
              waiting  time until it reaches 10 minutes which then will be the
              delay between the rest of the retries.  By  using  --retry-delay
              you   disable  this  exponential  backoff  algorithm.  See  also
              --retry-max-time to limit the total time allowed for retries.

              Since curl 7.66.0, curl will comply with  the  Retry-After:  re‐
              sponse  header if one was present to know when to issue the next
              retry.

              If this option is used several times, the last one will be used.

              Example:
               curl --retry 7 https://example.com

              See also --retry-max-time.

       --sasl-authzid <identity>
              Use this authorisation identity (authzid), during SASL PLAIN au‐
              thentication,  in addition to the authentication identity (auth‐
              cid) as specified by -u, --user.

              If the option is not specified, the server will derive  the  au‐
              thzid  from  the authcid, but if specified, and depending on the
              server implementation, it may be used to access  another  user's
              inbox,  that  the  user  has been granted access to, or a shared
              mailbox for example.

              Example:
               curl --sasl-authzid zid imap://example.com/

              See also --login-options. Added in 7.66.0.

       --sasl-ir
              Enable initial response in SASL authentication.

              Example:
               curl --sasl-ir imap://example.com/

              See also --sasl-authzid. Added in 7.31.0.

       --service-name <name>
              This option allows you to change the service name for SPNEGO.

              Examples:   --negotiate   --service-name   sockd    would    use
              sockd/server-name.

              Example:
               curl --service-name sockd/server https://example.com

              See also --negotiate and --proxy-service-name. Added in 7.43.0.

       -S, --show-error
              When used with -s, --silent, it makes curl show an error message
              if it fails.

              This option is global and does not need to be specified for each
              use of -:, --next.

              Example:
               curl --show-error --silent https://example.com

              See also --no-progress-meter.

       -s, --silent
              Silent  or  quiet mode. Do not show progress meter or error mes‐
              sages. Makes Curl mute. It will still output the  data  you  ask
              for, potentially even to the terminal/stdout unless you redirect
              it.

              Use -S, --show-error in  addition  to  this  option  to  disable
              progress meter but still show error messages.

              Example:
               curl -s https://example.com

              See also -v, --verbose, --stderr and --no-progress-meter.

       --socks4 <host[:port]>
              Use the specified SOCKS4 proxy. If the port number is not speci‐
              fied, it is assumed at port 1080. Using this  socket  type  make
              curl  resolve  the  host  name and passing the address on to the
              proxy.

              This option overrides any previous use of -x, --proxy,  as  they
              are mutually exclusive.

              This  option is superfluous since you can specify a socks4 proxy
              with -x, --proxy using a socks4:// protocol prefix.

              Since 7.52.0, --preproxy can be used to specify a SOCKS proxy at
              the  same  time -x, --proxy is used with an HTTP/HTTPS proxy. In
              such a case curl first connects to the SOCKS proxy and then con‐
              nects (through SOCKS) to the HTTP or HTTPS proxy.

              If this option is used several times, the last one will be used.

              Example:
               curl --socks4 hostname:4096 https://example.com

              See also --socks4a, --socks5 and --socks5-hostname.

       --socks4a <host[:port]>
              Use the specified SOCKS4a proxy. If the port number is not spec‐
              ified, it is assumed at port 1080. This asks the  proxy  to  re‐
              solve the host name.

              This  option  overrides any previous use of -x, --proxy, as they
              are mutually exclusive.

              This option is superfluous since you can specify a socks4a proxy
              with -x, --proxy using a socks4a:// protocol prefix.

              Since 7.52.0, --preproxy can be used to specify a SOCKS proxy at
              the same time -x, --proxy is used with an HTTP/HTTPS  proxy.  In
              such a case curl first connects to the SOCKS proxy and then con‐
              nects (through SOCKS) to the HTTP or HTTPS proxy.

              If this option is used several times, the last one will be used.

              Example:
               curl --socks4a hostname:4096 https://example.com

              See also --socks4, --socks5 and --socks5-hostname.

       --socks5-basic
              Tells curl to use username/password authentication when connect‐
              ing  to a SOCKS5 proxy.  The username/password authentication is
              enabled by default.  Use --socks5-gssapi to  force  GSS-API  au‐
              thentication to SOCKS5 proxies.

              Example:
               curl --socks5-basic --socks5 hostname:4096 https://example.com

              See also --socks5. Added in 7.55.0.

       --socks5-gssapi-nec
              As  part of the GSS-API negotiation a protection mode is negoti‐
              ated. RFC 1961 says in section 4.3/4.4 it should  be  protected,
              but  the  NEC  reference  implementation  does  not.  The option
              --socks5-gssapi-nec allows the unprotected exchange of the  pro‐
              tection mode negotiation.

              Example:
               curl --socks5-gssapi-nec --socks5 hostname:4096 https://example.com

              See also --socks5.

       --socks5-gssapi-service <name>
              The default service name for a socks server is rcmd/server-fqdn.
              This option allows you to change it.

              Examples:  --socks5  proxy-name  --socks5-gssapi-service   sockd
              would  use sockd/proxy-name --socks5 proxy-name --socks5-gssapi-
              service sockd/real-name  would  use  sockd/real-name  for  cases
              where the proxy-name does not match the principal name.

              Example:
               curl --socks5-gssapi-service sockd --socks5 hostname:4096 https://example.com

              See also --socks5.

       --socks5-gssapi
              Tells  curl  to  use GSS-API authentication when connecting to a
              SOCKS5 proxy.  The GSS-API authentication is enabled by  default
              (if  curl is compiled with GSS-API support).  Use --socks5-basic
              to force username/password authentication to SOCKS5 proxies.

              Example:
               curl --socks5-gssapi --socks5 hostname:4096 https://example.com

              See also --socks5. Added in 7.55.0.

       --socks5-hostname <host[:port]>
              Use the specified SOCKS5 proxy (and let the  proxy  resolve  the
              host  name).  If the port number is not specified, it is assumed
              at port 1080.

              This option overrides any previous use of -x, --proxy,  as  they
              are mutually exclusive.

              This  option is superfluous since you can specify a socks5 host‐
              name proxy with -x, --proxy using a socks5h:// protocol prefix.

              Since 7.52.0, --preproxy can be used to specify a SOCKS proxy at
              the  same  time -x, --proxy is used with an HTTP/HTTPS proxy. In
              such a case curl first connects to the SOCKS proxy and then con‐
              nects (through SOCKS) to the HTTP or HTTPS proxy.

              If this option is used several times, the last one will be used.

              Example:
               curl --socks5-hostname proxy.example:7000 https://example.com

              See also --socks5 and --socks4a.

       --socks5 <host[:port]>
              Use  the  specified SOCKS5 proxy - but resolve the host name lo‐
              cally. If the port number is not specified,  it  is  assumed  at
              port 1080.

              This  option  overrides any previous use of -x, --proxy, as they
              are mutually exclusive.

              This option is superfluous since you can specify a socks5  proxy
              with -x, --proxy using a socks5:// protocol prefix.

              Since 7.52.0, --preproxy can be used to specify a SOCKS proxy at
              the same time -x, --proxy is used with an HTTP/HTTPS  proxy.  In
              such a case curl first connects to the SOCKS proxy and then con‐
              nects (through SOCKS) to the HTTP or HTTPS proxy.

              If this option is used several times, the last one will be used.

              This option (as well as --socks4) does not work with IPV6,  FTPS
              or LDAP.

              Example:
               curl --socks5 proxy.example:7000 https://example.com

              See also --socks5-hostname and --socks4a.

       -Y, --speed-limit <speed>
              If a download is slower than this given speed (in bytes per sec‐
              ond) for speed-time seconds it gets aborted. speed-time  is  set
              with -y, --speed-time and is 30 if not set.

              If this option is used several times, the last one will be used.

              Example:
               curl --speed-limit 300 --speed-time 10 https://example.com

              See also -y, --speed-time, --limit-rate and -m, --max-time.

       -y, --speed-time <seconds>
              If a download is slower than speed-limit bytes per second during
              a speed-time period, the download gets aborted. If speed-time is
              used,  the  default  speed-limit  will  be 1 unless set with -Y,
              --speed-limit.

              This option controls transfers and thus  will  not  affect  slow
              connects  etc.  If this is a concern for you, try the --connect-
              timeout option.

              If this option is used several times, the last one will be used.

              Example:
               curl --speed-limit 300 --speed-time 10 https://example.com

              See also -Y, --speed-limit and --limit-rate.

       --ssl-allow-beast
              This option tells curl to not work around a security flaw in the
              SSL3 and TLS1.0 protocols known as BEAST.  If this option is not
              used, the SSL layer may use workarounds known to cause  interop‐
              erability problems with some older SSL implementations.

              WARNING: this option loosens the SSL security, and by using this
              flag you ask for exactly that.

              Example:
               curl --ssl-allow-beast https://example.com

              See also --proxy-ssl-allow-beast and -k, --insecure.

       --ssl-auto-client-cert
              Tell libcurl to automatically locate and use a  client  certifi‐
              cate  for authentication, when requested by the server. This op‐
              tion is only supported for Schannel (the native Windows SSL  li‐
              brary). Prior to 7.77.0 this was the default behavior in libcurl
              with Schannel. Since the server can request any certificate that
              supports  client  authentication  in the OS certificate store it
              could be a privacy violation and unexpected.

              Example:
               curl --ssl-auto-client-cert https://example.com

              See also --proxy-ssl-auto-client-cert. Added in 7.77.0.

       --ssl-no-revoke
              (Schannel) This option tells curl to disable certificate revoca‐
              tion checks.  WARNING: this option loosens the SSL security, and
              by using this flag you ask for exactly that.

              Example:
               curl --ssl-no-revoke https://example.com

              See also --crlfile. Added in 7.44.0.

       --ssl-reqd
              (FTP IMAP POP3 SMTP LDAP) Require SSL/TLS  for  the  connection.
              Terminates  the  connection  if  the  server  does  not  support
              SSL/TLS.

              This option is handled in LDAP since version 7.81.0. It is fully
              supported  by  the  openldap backend and rejected by the generic
              ldap backend if explicit TLS is required.

              This option was formerly known as --ftp-ssl-reqd.

              Example:
               curl --ssl-reqd ftp://example.com

              See also --ssl and -k, --insecure.

       --ssl-revoke-best-effort
              (Schannel) This option tells curl to ignore certificate  revoca‐
              tion checks when they failed due to missing/offline distribution
              points for the revocation check lists.

              Example:
               curl --ssl-revoke-best-effort https://example.com

              See also --crlfile and -k, --insecure. Added in 7.70.0.

       --ssl  (FTP IMAP POP3 SMTP LDAP) Try to use SSL/TLS for the connection.
              Reverts  to  a non-secure connection if the server does not sup‐
              port SSL/TLS. See also --ftp-ssl-control and --ssl-reqd for dif‐
              ferent levels of encryption required.

              This option is handled in LDAP since version 7.81.0. It is fully
              supported by the openldap backend and  ignored  by  the  generic
              ldap backend.

              Please  note that a server may close the connection if the nego‐
              tiation does not succeed.

              This option was formerly known as --ftp-ssl.  That  option  name
              can still be used but will be removed in a future version.

              Example:
               curl --ssl pop3://example.com/

              See also -k, --insecure and --ciphers.

       -2, --sslv2
              (SSL) This option previously asked curl to use SSLv2, but start‐
              ing in curl 7.77.0 this instruction is ignored. SSLv2 is  widely
              considered insecure (see RFC 6176).

              Example:
               curl --sslv2 https://example.com

              See  also  --http1.1  and --http2. -2, --sslv2 requires that the
              underlying libcurl was built to support TLS. This  option  over‐
              rides -3, --sslv3 and -1, --tlsv1 and --tlsv1.1 and --tlsv1.2.

       -3, --sslv3
              (SSL) This option previously asked curl to use SSLv3, but start‐
              ing in curl 7.77.0 this instruction is ignored. SSLv3 is  widely
              considered insecure (see RFC 7568).

              Example:
               curl --sslv3 https://example.com

              See  also  --http1.1  and --http2. -3, --sslv3 requires that the
              underlying libcurl was built to support TLS. This  option  over‐
              rides -2, --sslv2 and -1, --tlsv1 and --tlsv1.1 and --tlsv1.2.

       --stderr <file>
              Redirect  all writes to stderr to the specified file instead. If
              the file name is a plain '-', it is instead written to stdout.

              This option is global and does not need to be specified for each
              use of -:, --next.

              If this option is used several times, the last one will be used.

              Example:
               curl --stderr output.txt https://example.com

              See also -v, --verbose and -s, --silent.

       --styled-output
              Enables  the automatic use of bold font styles when writing HTTP
              headers to the terminal. Use --no-styled-output to  switch  them
              off.

              This option is global and does not need to be specified for each
              use of -:, --next.

              Example:
               curl --styled-output -I https://example.com

              See also -I, --head and -v, --verbose. Added in 7.61.0.

       --suppress-connect-headers
              When -p, --proxytunnel is used and a CONNECT request is made  do
              not  output proxy CONNECT response headers. This option is meant
              to be used with -D, --dump-header or  -i,  --include  which  are
              used to show protocol headers in the output. It has no effect on
              debug options such as -v, --verbose or --trace, or  any  statis‐
              tics.

              Example:
               curl --suppress-connect-headers --include -x proxy https://example.com

              See also -D, --dump-header, -i, --include and -p, --proxytunnel.
              Added in 7.54.0.

       --tcp-fastopen
              Enable use of TCP Fast Open (RFC7413).

              Example:
               curl --tcp-fastopen https://example.com

              See also --false-start. Added in 7.49.0.

       --tcp-nodelay
              Turn on the TCP_NODELAY option. See the curl_easy_setopt(3)  man
              page for details about this option.

              Since  7.50.2,  curl sets this option by default and you need to
              explicitly switch it off if you do not want it on.

              Example:
               curl --tcp-nodelay https://example.com

              See also -N, --no-buffer.

       -t, --telnet-option <opt=val>
              Pass options to the telnet protocol. Supported options are:

              TTYPE=<term> Sets the terminal type.

              XDISPLOC=<X display> Sets the X display location.

              NEW_ENV=<var,val> Sets an environment variable.

              Example:
               curl -t TTYPE=vt100 telnet://example.com/

              See also -K, --config.

       --tftp-blksize <value>
              (TFTP) Set TFTP BLKSIZE option (must be >512). This is the block
              size that curl will try to use when transferring data to or from
              a TFTP server. By default 512 bytes will be used.

              If this option is used several times, the last one will be used.

              Example:
               curl --tftp-blksize 1024 tftp://example.com/file

              See also --tftp-no-options.

       --tftp-no-options
              (TFTP) Tells curl not to send TFTP options requests.

              This option improves interop with some legacy  servers  that  do
              not  acknowledge  or  properly implement TFTP options. When this
              option is used --tftp-blksize is ignored.

              Example:
               curl --tftp-no-options tftp://192.168.0.1/

              See also --tftp-blksize. Added in 7.48.0.

       -z, --time-cond <time>
              (HTTP FTP) Request a file that has been modified later than  the
              given  time  and date, or one that has been modified before that
              time. The <date expression> can be all sorts of date strings  or
              if  it  does not match any internal ones, it is taken as a file‐
              name and tries to get the modification date (mtime) from  <file>
              instead.  See  the curl_getdate(3) man pages for date expression
              details.

              Start the date expression with a dash (-) to make it request for
              a  document that is older than the given date/time, default is a
              document that is newer than the specified date/time.

              If this option is used several times, the last one will be used.

              Examples:
               curl -z "Wed 01 Sep 2021 12:18:00" https://example.com
               curl -z "-Wed 01 Sep 2021 12:18:00" https://example.com
               curl -z file https://example.com

              See also --etag-compare and -R, --remote-time.

       --tls-max <VERSION>
              (SSL) VERSION defines maximum supported TLS version. The minimum
              acceptable  version  is  set  by  tlsv1.0,  tlsv1.1,  tlsv1.2 or
              tlsv1.3.

              If the connection is done without TLS, this option  has  no  ef‐
              fect. This includes QUIC-using (HTTP/3) transfers.

              default
                     Use up to recommended TLS version.

              1.0    Use up to TLSv1.0.

              1.1    Use up to TLSv1.1.

              1.2    Use up to TLSv1.2.

              1.3    Use up to TLSv1.3.

       Examples:
        curl --tls-max 1.2 https://example.com
        curl --tls-max 1.3 --tlsv1.2 https://example.com

       See  also  --tlsv1.0, --tlsv1.1, --tlsv1.2 and --tlsv1.3. --tls-max re‐
       quires that the underlying libcurl was built to support TLS.  Added  in
       7.54.0.

       --tls13-ciphers <ciphersuite list>
              (TLS)  Specifies which cipher suites to use in the connection if
              it negotiates TLS 1.3. The list of ciphers suites  must  specify
              valid  ciphers.  Read up on TLS 1.3 cipher suite details on this
              URL:

               https://curl.se/docs/ssl-ciphers.html

              This option is currently used only when curl  is  built  to  use
              OpenSSL 1.1.1 or later. If you are using a different SSL backend
              you can try setting TLS 1.3 cipher suites by using the --ciphers
              option.

              If this option is used several times, the last one will be used.

              Example:
               curl --tls13-ciphers TLS_AES_128_GCM_SHA256 https://example.com

              See also --ciphers and --curves. Added in 7.61.0.

       --tlsauthtype <type>
              Set  TLS  authentication type. Currently, the only supported op‐
              tion  is  "SRP",  for  TLS-SRP  (RFC  5054).  If  --tlsuser  and
              --tlspassword  are specified but --tlsauthtype is not, then this
              option defaults to "SRP". This option works only if the underly‐
              ing  libcurl  is  built  with  TLS-SRP  support,  which requires
              OpenSSL or GnuTLS with TLS-SRP support.

              Example:
               curl --tlsauthtype SRP https://example.com

              See also --tlsuser.

       --tlspassword <string>
              Set password for use with the TLS authentication  method  speci‐
              fied with --tlsauthtype. Requires that --tlsuser also be set.

              This option does not work with TLS 1.3.

              Example:
               curl --tlspassword pwd --tlsuser user https://example.com

              See also --tlsuser.

       --tlsuser <name>
              Set  username  for use with the TLS authentication method speci‐
              fied with --tlsauthtype. Requires  that  --tlspassword  also  is
              set.

              This option does not work with TLS 1.3.

              Example:
               curl --tlspassword pwd --tlsuser user https://example.com

              See also --tlspassword.

       --tlsv1.0
              (TLS)  Forces curl to use TLS version 1.0 or later when connect‐
              ing to a remote TLS server.

              In old versions of curl this  option  was  documented  to  allow
              _only_ TLS 1.0.  That behavior was inconsistent depending on the
              TLS library. Use --tls-max if you want to set a maximum TLS ver‐
              sion.

              Example:
               curl --tlsv1.0 https://example.com

              See also --tlsv1.3. Added in 7.34.0.

       --tlsv1.1
              (TLS)  Forces curl to use TLS version 1.1 or later when connect‐
              ing to a remote TLS server.

              In old versions of curl this  option  was  documented  to  allow
              _only_ TLS 1.1.  That behavior was inconsistent depending on the
              TLS library. Use --tls-max if you want to set a maximum TLS ver‐
              sion.

              Example:
               curl --tlsv1.1 https://example.com

              See also --tlsv1.3. Added in 7.34.0.

       --tlsv1.2
              (TLS)  Forces curl to use TLS version 1.2 or later when connect‐
              ing to a remote TLS server.

              In old versions of curl this  option  was  documented  to  allow
              _only_ TLS 1.2.  That behavior was inconsistent depending on the
              TLS library. Use --tls-max if you want to set a maximum TLS ver‐
              sion.

              Example:
               curl --tlsv1.2 https://example.com

              See also --tlsv1.3. Added in 7.34.0.

       --tlsv1.3
              (TLS)  Forces curl to use TLS version 1.3 or later when connect‐
              ing to a remote TLS server.

              If the connection is done without TLS, this option  has  no  ef‐
              fect. This includes QUIC-using (HTTP/3) transfers.

              Note that TLS 1.3 is not supported by all TLS backends.

              Example:
               curl --tlsv1.3 https://example.com

              See also --tlsv1.2. Added in 7.52.0.

       -1, --tlsv1
              (SSL)  Tells curl to use at least TLS version 1.x when negotiat‐
              ing with a remote TLS server. That  means  TLS  version  1.0  or
              higher

              Example:
               curl --tlsv1 https://example.com

              See  also  --http1.1  and --http2. -1, --tlsv1 requires that the
              underlying libcurl was built to support TLS. This  option  over‐
              rides --tlsv1.1 and --tlsv1.2 and --tlsv1.3.

       --tr-encoding
              (HTTP) Request a compressed Transfer-Encoding response using one
              of the algorithms curl supports, and uncompress the  data  while
              receiving it.

              Example:
               curl --tr-encoding https://example.com

              See also --compressed.

       --trace-ascii <file>
              Enables a full trace dump of all incoming and outgoing data, in‐
              cluding descriptive information, to the given output  file.  Use
              "-" as filename to have the output sent to stdout.

              This is similar to --trace, but leaves out the hex part and only
              shows the ASCII part of the dump. It makes smaller  output  that
              might be easier to read for untrained humans.

              This option is global and does not need to be specified for each
              use of -:, --next.

              If this option is used several times, the last one will be used.

              Example:
               curl --trace-ascii log.txt https://example.com

              See also  -v,  --verbose  and  --trace.  This  option  overrides
              --trace and -v, --verbose.

       --trace-time
              Prepends  a  time  stamp to each trace or verbose line that curl
              displays.

              This option is global and does not need to be specified for each
              use of -:, --next.

              Example:
               curl --trace-time --trace-ascii output https://example.com

              See also --trace and -v, --verbose.

       --trace <file>
              Enables a full trace dump of all incoming and outgoing data, in‐
              cluding descriptive information, to the given output  file.  Use
              "-"  as  filename  to have the output sent to stdout. Use "%" as
              filename to have the output sent to stderr.

              This option is global and does not need to be specified for each
              use of -:, --next.

              If this option is used several times, the last one will be used.

              Example:
               curl --trace log.txt https://example.com

              See  also  --trace-ascii and --trace-time. This option overrides
              -v, --verbose and --trace-ascii.

       --unix-socket <path>
              (HTTP) Connect through this Unix domain socket, instead of using
              the network.

              Example:
               curl --unix-socket socket-path https://example.com

              See also --abstract-unix-socket. Added in 7.40.0.

       -T, --upload-file <file>
              This  transfers  the  specified local file to the remote URL. If
              there is no file part in the specified URL, curl will append the
              local file name. NOTE that you must use a trailing / on the last
              directory to really prove to Curl that there is no file name  or
              curl will think that your last directory name is the remote file
              name to use. That will most likely cause the upload operation to
              fail. If this is used on an HTTP(S) server, the PUT command will
              be used.

              Use the file name "-" (a single dash) to use stdin instead of  a
              given  file.   Alternately,  the file name "." (a single period)
              may be specified instead of "-" to  use  stdin  in  non-blocking
              mode  to  allow  reading  server output while stdin is being up‐
              loaded.

              You can specify one -T, --upload-file for each URL on  the  com‐
              mand  line.  Each -T, --upload-file + URL pair specifies what to
              upload and to where. curl also supports "globbing"  of  the  -T,
              --upload-file  argument,  meaning  that  you can upload multiple
              files to a single URL by using the same URL globbing style  sup‐
              ported in the URL.

              When  uploading  to an SMTP server: the uploaded data is assumed
              to be RFC 5322 formatted. It has to feature the necessary set of
              headers  and  mail  body formatted correctly by the user as curl
              will not transcode nor encode it further in any way.

              Examples:
               curl -T file https://example.com
               curl -T "img[1-1000].png" ftp://ftp.example.com/
               curl --upload-file "{file1,file2}" https://example.com

              See also -G, --get and -I, --head.

       --url <url>
              Specify a URL to fetch. This option is  mostly  handy  when  you
              want to specify URL(s) in a config file.

              If  the given URL is missing a scheme name (such as "http://" or
              "ftp://" etc) then curl will make a guess based on the host.  If
              the  outermost  sub-domain  name  matches DICT, FTP, IMAP, LDAP,
              POP3 or SMTP then that protocol will  be  used,  otherwise  HTTP
              will be used. Since 7.45.0 guessing can be disabled by setting a
              default protocol, see --proto-default for details.

              This option may be used any number of times.  To  control  where
              this  URL  is written, use the -o, --output or the -O, --remote-
              name options.

              WARNING: On Windows, particular file://  accesses  can  be  con‐
              verted to network accesses by the operating system. Beware!

              Example:
               curl --url https://example.com

              See also -:, --next and -K, --config.

       -B, --use-ascii
              (FTP  LDAP) Enable ASCII transfer. For FTP, this can also be en‐
              forced by using a URL that  ends  with  ";type=A".  This  option
              causes data sent to stdout to be in text mode for win32 systems.

              Example:
               curl -B ftp://example.com/README

              See also --crlf and --data-ascii.

       -A, --user-agent <name>
              (HTTP) Specify the User-Agent string to send to the HTTP server.
              To encode blanks in the string, surround the string with  single
              quote  marks.  This header can also be set with the -H, --header
              or the --proxy-header options.

              If you give an empty argument to -A, --user-agent (""), it  will
              remove  the  header completely from the request. If you prefer a
              blank header, you can set it to a single space (" ").

              If this option is used several times, the last one will be used.

              Example:
               curl -A "Agent 007" https://example.com

              See also -H, --header and --proxy-header.

       -u, --user <user:password>
              Specify the user name and password to use for server authentica‐
              tion. Overrides -n, --netrc and --netrc-optional.

              If  you  simply  specify  the  user name, curl will prompt for a
              password.

              The user name and passwords are split up  on  the  first  colon,
              which  makes  it impossible to use a colon in the user name with
              this option. The password can, still.

              On systems where it works, curl will hide the given option argu‐
              ment  from  process listings. This is not enough to protect cre‐
              dentials from possibly getting seen by other users on  the  same
              system  as  they  will  still  be  visible  for  a moment before
              cleared. Such sensitive data should be retrieved from a file in‐
              stead or similar and never used in clear text in a command line.

              When  using  Kerberos  V5 with a Windows based server you should
              include the Windows domain name in the user name, in  order  for
              the  server  to successfully obtain a Kerberos Ticket. If you do
              not, then the initial authentication handshake may fail.

              When using NTLM, the user name can be specified  simply  as  the
              user  name,  without the domain, if there is a single domain and
              forest in your setup for example.

              To specify the domain name use either Down-Level Logon  Name  or
              UPN (User Principal Name) formats. For example, EXAMPLE\user and
              [email protected] respectively.

              If you use a Windows SSPI-enabled curl binary and  perform  Ker‐
              beros  V5, Negotiate, NTLM or Digest authentication then you can
              tell curl to select the user name and password from  your  envi‐
              ronment by specifying a single colon with this option: "-u :".

              If this option is used several times, the last one will be used.

              Example:
               curl -u user:secret https://example.com

              See also -n, --netrc and -K, --config.

       -v, --verbose
              Makes  curl  verbose  during the operation. Useful for debugging
              and seeing what's going on "under the  hood".  A  line  starting
              with  '>'  means  "header  data" sent by curl, '<' means "header
              data" received by curl that is hidden in  normal  cases,  and  a
              line starting with '*' means additional info provided by curl.

              If you only want HTTP headers in the output, -i, --include might
              be the option you are looking for.

              If you think this option still does not give you enough details,
              consider using --trace or --trace-ascii instead.

              This option is global and does not need to be specified for each
              use of -:, --next.

              Use -s, --silent to make curl really quiet.

              Example:
               curl --verbose https://example.com

              See also  -i,  --include.  This  option  overrides  --trace  and
              --trace-ascii.

       -V, --version
              Displays information about curl and the libcurl version it uses.

              The  first  line  includes the full version of curl, libcurl and
              other 3rd party libraries linked with the executable.

              The second line (starts with "Protocols:") shows  all  protocols
              that libcurl reports to support.

              The third line (starts with "Features:") shows specific features
              libcurl reports to offer. Available features include:

              alt-svc
                     Support for the Alt-Svc: header is provided.

              AsynchDNS
                     This curl uses asynchronous name  resolves.  Asynchronous
                     name  resolves can be done using either the c-ares or the
                     threaded resolver backends.

              brotli Support for automatic brotli compression over HTTP(S).

              CharConv
                     curl was built with support for character set conversions
                     (like EBCDIC)

              Debug  This  curl  uses a libcurl built with Debug. This enables
                     more error-tracking and memory debugging etc.  For  curl-
                     developers only!

              gsasl  The  built-in  SASL authentication includes extensions to
                     support SCRAM because libcurl was built with libgsasl.

              GSS-API
                     GSS-API is supported.

              HSTS   HSTS support is present.

              HTTP2  HTTP/2 support has been built-in.

              HTTP3  HTTP/3 support has been built-in.

              HTTPS-proxy
                     This curl is built to support HTTPS proxy.

              IDN    This curl supports IDN - international domain names.

              IPv6   You can use IPv6 with this.

              Kerberos
                     Kerberos V5 authentication is supported.

              Largefile
                     This curl supports transfers of large files, files larger
                     than 2GB.

              libz   Automatic decompression (via gzip, deflate) of compressed
                     files over HTTP is supported.

              MultiSSL
                     This curl supports multiple TLS backends.

              NTLM   NTLM authentication is supported.

              NTLM_WB
                     NTLM delegation to winbind helper is supported.

              PSL    PSL is short for Public Suffix List and means  that  this
                     curl  has  been  built  with knowledge about "public suf‐
                     fixes".

              SPNEGO SPNEGO authentication is supported.

              SSL    SSL versions of various protocols are supported, such  as
                     HTTPS, FTPS, POP3S and so on.

              SSPI   SSPI is supported.

              TLS-SRP
                     SRP  (Secure Remote Password) authentication is supported
                     for TLS.

              TrackMemory
                     Debug memory tracking is supported.

              Unicode
                     Unicode support on Windows.

              UnixSockets
                     Unix sockets support is provided.

              zstd   Automatic decompression (via zstd)  of  compressed  files
                     over HTTP is supported.

       Example:
        curl --version

       See also -h, --help and -M, --manual.

       -w, --write-out <format>
              Make curl display information on stdout after a completed trans‐
              fer. The format is a string that may contain  plain  text  mixed
              with  any  number of variables. The format can be specified as a
              literal "string", or you can have curl read the  format  from  a
              file  with  "@filename" and to tell curl to read the format from
              stdin you write "@-".

              The variables present in the output format will  be  substituted
              by  the  value or text that curl thinks fit, as described below.
              All variables are specified as %{variable_name} and to output  a
              normal  % you just write them as %%. You can output a newline by
              using \n, a carriage return with \r and a tab space with \t.

              The output will be written to standard output, but this  can  be
              switched to standard error by using %{stderr}.

              NOTE: The %-symbol is a special symbol in the win32-environment,
              where all occurrences of % must be doubled when using  this  op‐
              tion.

              The variables available are:

              content_type   The  Content-Type  of  the requested document, if
                             there was any.

              errormsg       The error message. (Added in 7.75.0)

              exitcode       The numerical exitcode of the transfer. (Added in
                             7.75.0)

              filename_effective
                             The  ultimate  filename  that curl writes out to.
                             This is only meaningful if curl is told to  write
                             to  a  file  with  the  -O,  --remote-name or -o,
                             --output option. It's most useful in  combination
                             with the -J, --remote-header-name option.

              ftp_entry_path The initial path curl ended up in when logging on
                             to the remote FTP server.

              http_code      The numerical response code that was found in the
                             last retrieved HTTP(S) or FTP(s) transfer.

              http_connect   The numerical code that was found in the last re‐
                             sponse (from a proxy) to a curl CONNECT request.

              http_version   The  http  version  that  was  effectively  used.
                             (Added in 7.50.0)

              json           A JSON object with all available keys.

              local_ip       The  IP  address of the local end of the most re‐
                             cently done connection - can be  either  IPv4  or
                             IPv6.

              local_port     The  local  port number of the most recently done
                             connection.

              method         The http method used in the most recent HTTP  re‐
                             quest. (Added in 7.72.0)

              num_connects   Number  of new connects made in the recent trans‐
                             fer.

              num_headers    The number of response headers in the most recent
                             request (restarted at each
                              redirect). Note that the status line IS NOT a header. (Added in 7.73.0)

              num_redirects  Number of redirects that were followed in the re‐
                             quest.

              onerror        The rest of the  output  is  only  shown  if  the
                             transfer  returned  a  non-zero  error  (Added in
                             7.75.0)

              proxy_ssl_verify_result
                             The result of the HTTPS proxy's SSL peer certifi‐
                             cate verification that was requested. 0 means the
                             verification was successful. (Added in 7.52.0)

              redirect_url   When an HTTP request was made without -L, --loca‐
                             tion to follow redirects (or when --max-redirs is
                             met), this variable will show the  actual  URL  a
                             redirect would have gone to.

              referer        The  Referer: header, if there was any. (Added in
                             7.76.0)

              remote_ip      The remote IP address of the most  recently  done
                             connection - can be either IPv4 or IPv6.

              remote_port    The  remote port number of the most recently done
                             connection.

              response_code  The numerical response code that was found in the
                             last transfer (formerly known as "http_code").

              scheme         The  URL  scheme (sometimes called protocol) that
                             was effectively used. (Added in 7.52.0)

              size_download  The total amount of bytes that  were  downloaded.
                             This is the size of the body/data that was trans‐
                             ferred, excluding headers.

              size_header    The total amount of bytes of the downloaded head‐
                             ers.

              size_request   The  total  amount of bytes that were sent in the
                             HTTP request.

              size_upload    The total amount of  bytes  that  were  uploaded.
                             This is the size of the body/data that was trans‐
                             ferred, excluding headers.

              speed_download The average download speed that curl measured for
                             the complete download. Bytes per second.

              speed_upload   The  average  upload speed that curl measured for
                             the complete upload. Bytes per second.

              ssl_verify_result
                             The result of the SSL peer certificate  verifica‐
                             tion that was requested. 0 means the verification
                             was successful.

              stderr         From this point on, the  -w,  --write-out  output
                             will  be  written  to  standard  error. (Added in
                             7.63.0)

              stdout         From this point on, the  -w,  --write-out  output
                             will  be written to standard output.  This is the
                             default, but can be used  to  switch  back  after
                             switching to stderr.  (Added in 7.63.0)

              time_appconnect
                             The  time, in seconds, it took from the start un‐
                             til the SSL/SSH/etc connect/handshake to the  re‐
                             mote host was completed.

              time_connect   The  time, in seconds, it took from the start un‐
                             til the TCP connect to the remote host (or proxy)
                             was completed.

              time_namelookup
                             The  time, in seconds, it took from the start un‐
                             til the name resolving was completed.

              time_pretransfer
                             The time, in seconds, it took from the start  un‐
                             til  the  file  transfer was just about to begin.
                             This includes all pre-transfer commands and nego‐
                             tiations that are specific to the particular pro‐
                             tocol(s) involved.

              time_redirect  The time, in seconds, it took for all redirection
                             steps including name lookup, connect, pretransfer
                             and transfer before  the  final  transaction  was
                             started.  time_redirect shows the complete execu‐
                             tion time for multiple redirections.

              time_starttransfer
                             The time, in seconds, it took from the start  un‐
                             til  the  first  byte was just about to be trans‐
                             ferred. This includes time_pretransfer  and  also
                             the  time  the server needed to calculate the re‐
                             sult.

              time_total     The total time, in seconds, that the full  opera‐
                             tion lasted.

              url            The URL that was fetched. (Added in 7.75.0)

              urlnum         The URL index number of this transfer, 0-indexed.
                             De-globbed URLs share the same  index  number  as
                             the origin globbed URL. (Added in 7.75.0)

              url_effective  The URL that was fetched last. This is most mean‐
                             ingful if you have told curl to follow  location:
                             headers.

              If this option is used several times, the last one will be used.

              Example:
               curl -w '%{
    
    http_code}\n' https://example.com

              See also -v, --verbose and -I, --head.

       --xattr
              When  saving  output  to a file, this option tells curl to store
              certain file metadata in extended  file  attributes.  Currently,
              the URL is stored in the xdg.origin.url attribute and, for HTTP,
              the content type is stored in the mime_type  attribute.  If  the
              file  system  does not support extended attributes, a warning is
              issued.

              Example:
               curl --xattr -o storage https://example.com

              See also -R, --remote-time, -w, --write-out and -v, --verbose.

FILES
       ~/.curlrc
              Default config file, see -K, --config for details.

ENVIRONMENT
       The environment variables can be specified in lower case or upper case.
       The lower case version has precedence. http_proxy is an exception as it
       is only available in lower case.

       Using an environment variable to set the proxy has the same  effect  as
       using the -x, --proxy option.

       http_proxy [protocol://]<host>[:port]
              Sets the proxy server to use for HTTP.

       HTTPS_PROXY [protocol://]<host>[:port]
              Sets the proxy server to use for HTTPS.

       [url-protocol]_PROXY [protocol://]<host>[:port]
              Sets  the proxy server to use for [url-protocol], where the pro‐
              tocol is a protocol that curl supports and  as  specified  in  a
              URL. FTP, FTPS, POP3, IMAP, SMTP, LDAP, etc.

       ALL_PROXY [protocol://]<host>[:port]
              Sets  the  proxy  server to use if no protocol-specific proxy is
              set.

       NO_PROXY <comma-separated list of hosts/domains>
              list of host names that should not go through any proxy. If  set
              to an asterisk '*' only, it matches all hosts. Each name in this
              list is matched as either a domain name which contains the host‐
              name, or the hostname itself.

              This  environment  variable  disables use of the proxy even when
              specified with the -x,  --proxy  option.  That  is  NO_PROXY=di‐
              rect.example.com  curl  -x  http://proxy.example.com  http://di‐
              rect.example.com  accesses  the   target   URL   directly,   and
              NO_PROXY=direct.example.com   curl  -x  http://proxy.example.com
              http://somewhere.example.com accesses the target URL through the
              proxy.

              The  list  of  host  names  can also be include numerical IP ad‐
              dresses, and IPv6 versions should then be given without  enclos‐
              ing brackets.

              IPv6  numerical  addresses are compared as strings, so they will
              only match if the representations are the  same:  "::1"  is  the
              same as "::0:1" but they do not match.

       APPDATA <dir>
              On  Windows,  this variable is used when trying to find the home
              directory. If the primary home variable are all unset.

       COLUMNS <terminal width>
              If set, the specified number of characters will be used  as  the
              terminal  width  when  the alternative progress-bar is shown. If
              not set, curl will try to figure it out using other ways.

       CURL_CA_BUNDLE <file>
              If set, will be used as the --cacert value.

       CURL_HOME <dir>
              If set, is the first variable curl checks when  trying  to  find
              its  home  directory. If not set, it continues to check XDG_CON‐
              FIG_HOME.

       CURL_SSL_BACKEND <TLS backend>
              If curl was built with support for "MultiSSL", meaning  that  it
              has  built-in  support for more than one TLS backend, this envi‐
              ronment variable can be set to the case insensitive name of  the
              particular  backend  to use when curl is invoked. Setting a name
              that is not a built-in alternative will make curl stay with  the
              default.

              SSL  backend  names  (case-insensitive): bearssl, gnutls, gskit,
              mbedtls, mesalink, nss, openssl, rustls, schannel, secure-trans‐
              port, wolfssl

       HOME <dir>
              If  set,  this  is  used to find the home directory when that is
              needed. Like when looking for the default .curlrc. CURL_HOME and
              XDG_CONFIG_HOME have preference.

       QLOGDIR <directory name>
              If  curl was built with HTTP/3 support, setting this environment
              variable to a local directory will make curl  produce  qlogs  in
              that  directory,  using  file  names named after the destination
              connection id (in hex). Do note  that  these  files  can  become
              rather large. Works with both QUIC backends.

       SHELL  Used  on  VMS  when  trying to detect if using a DCL or a "unix"
              shell.

       SSL_CERT_DIR <dir>
              If set, will be used as the --capath value.

       SSL_CERT_FILE <path>
              If set, will be used as the --cacert value.

       SSLKEYLOGFILE <file name>
              If you set this environment variable to a file name,  curl  will
              store TLS secrets from its connections in that file when invoked
              to enable you to analyze the TLS traffic in real time using net‐
              work analyzing tools such as Wireshark. This works with the fol‐
              lowing TLS backends: OpenSSL, libressl, BoringSSL,  GnuTLS,  NSS
              and wolfSSL.

       USERPROFILE <dir>
              On  Windows,  this variable is used when trying to find the home
              directory. If the other, primary, variable  are  all  unset.  If
              set, curl will use the path "$USERPROFILE\Application Data".

       XDG_CONFIG_HOME <dir>
              If  CURL_HOME  is not set, this variable is checked when looking
              for a default .curlrc file.

PROXY PROTOCOL PREFIXES
       The proxy string may be specified with a protocol:// prefix to  specify
       alternative proxy protocols.

       If  no  protocol is specified in the proxy string or if the string does
       not match a supported one, the proxy will be treated as an HTTP proxy.

       The supported proxy protocol prefixes are as follows:

       http://
              Makes it use it as an HTTP proxy. The default if no scheme  pre‐
              fix is used.

       https://
              Makes it treated as an HTTPS proxy.

       socks4://
              Makes it the equivalent of --socks4

       socks4a://
              Makes it the equivalent of --socks4a

       socks5://
              Makes it the equivalent of --socks5

       socks5h://
              Makes it the equivalent of --socks5-hostname

EXIT CODES
       There  are a bunch of different error codes and their corresponding er‐
       ror messages that may appear under error conditions.  At  the  time  of
       this writing, the exit codes are:

       1      Unsupported protocol. This build of curl has no support for this
              protocol.

       2      Failed to initialize.

       3      URL malformed. The syntax was not correct.

       4      A feature or option that was needed to perform the  desired  re‐
              quest  was not enabled or was explicitly disabled at build-time.
              To make curl able to do this, you probably need another build of
              libcurl.

       5      Could  not  resolve proxy. The given proxy host could not be re‐
              solved.

       6      Could not resolve host. The given remote host could not  be  re‐
              solved.

       7      Failed to connect to host.

       8      Weird server reply. The server sent data curl could not parse.

       9      FTP  access  denied. The server denied login or denied access to
              the particular resource or directory you wanted to  reach.  Most
              often  you tried to change to a directory that does not exist on
              the server.

       10     FTP accept failed. While waiting for the server to connect  back
              when  an active FTP session is used, an error code was sent over
              the control connection or similar.

       11     FTP weird PASS reply. Curl could not parse the reply sent to the
              PASS request.

       12     During  an  active  FTP  session while waiting for the server to
              connect back to curl, the timeout expired.

       13     FTP weird PASV reply, Curl could not parse the reply sent to the
              PASV request.

       14     FTP  weird  227  format.  Curl  could not parse the 227-line the
              server sent.

       15     FTP cannot use host. Could not resolve the host IP we got in the
              227-line.

       16     HTTP/2 error. A problem was detected in the HTTP2 framing layer.
              This is somewhat generic and can be one out of several problems,
              see the error message for details.

       17     FTP  could  not  set binary. Could not change transfer method to
              binary.

       18     Partial file. Only a part of the file was transferred.

       19     FTP could not download/access the given file, the RETR (or simi‐
              lar) command failed.

       21     FTP quote error. A quote command returned error from the server.

       22     HTTP  page not retrieved. The requested url was not found or re‐
              turned another error with the  HTTP  error  code  being  400  or
              above. This return code only appears if -f, --fail is used.

       23     Write  error. Curl could not write data to a local filesystem or
              similar.

       25     FTP could not STOR file. The server denied the  STOR  operation,
              used for FTP uploading.

       26     Read error. Various reading problems.

       27     Out of memory. A memory allocation request failed.

       28     Operation timeout. The specified time-out period was reached ac‐
              cording to the conditions.

       30     FTP PORT failed. The PORT command failed. Not  all  FTP  servers
              support  the  PORT  command, try doing a transfer using PASV in‐
              stead!

       31     FTP could not use REST. The REST command failed. This command is
              used for resumed FTP transfers.

       33     HTTP range error. The range "command" did not work.

       34     HTTP post error. Internal post-request generation error.

       35     SSL connect error. The SSL handshaking failed.

       36     Bad download resume. Could not continue an earlier aborted down‐
              load.

       37     FILE could not read file. Failed to open the file. Permissions?

       38     LDAP cannot bind. LDAP bind operation failed.

       39     LDAP search failed.

       41     Function not found. A required LDAP function was not found.

       42     Aborted by callback. An application told curl to abort the oper‐
              ation.

       43     Internal error. A function was called with a bad parameter.

       45     Interface  error.  A  specified  outgoing interface could not be
              used.

       47     Too many redirects. When following redirects, curl hit the maxi‐
              mum amount.

       48     Unknown  option  specified  to  libcurl. This indicates that you
              passed a weird option to curl that was passed on to libcurl  and
              rejected. Read up in the manual!

       49     Malformed telnet option.

       51     The peer's SSL certificate or SSH MD5 fingerprint was not OK.

       52     The  server  did not reply anything, which here is considered an
              error.

       53     SSL crypto engine not found.

       54     Cannot set SSL crypto engine as default.

       55     Failed sending network data.

       56     Failure in receiving network data.

       58     Problem with the local certificate.

       59     Could not use specified SSL cipher.

       60     Peer certificate cannot be authenticated with known CA  certifi‐
              cates.

       61     Unrecognized transfer encoding.

       62     Invalid LDAP URL.

       63     Maximum file size exceeded.

       64     Requested FTP SSL level failed.

       65     Sending the data requires a rewind that failed.

       66     Failed to initialise SSL Engine.

       67     The  user  name,  password, or similar was not accepted and curl
              failed to log in.

       68     File not found on TFTP server.

       69     Permission problem on TFTP server.

       70     Out of disk space on TFTP server.

       71     Illegal TFTP operation.

       72     Unknown TFTP transfer ID.

       73     File already exists (TFTP).

       74     No such user (TFTP).

       75     Character conversion failed.

       76     Character conversion functions required.

       77     Problem reading the SSL CA cert (path? access rights?).

       78     The resource referenced in the URL does not exist.

       79     An unspecified error occurred during the SSH session.

       80     Failed to shut down the SSL connection.

       82     Could not load CRL file, missing or wrong format.

       83     Issuer check failed.

       84     The FTP PRET command failed.

       85     Mismatch of RTSP CSeq numbers.

       86     Mismatch of RTSP Session Identifiers.

       87     Unable to parse FTP file list.

       88     FTP chunk callback reported error.

       89     No connection available, the session will be queued.

       90     SSL public key does not matched pinned public key.

       91     Invalid SSL certificate status.

       92     Stream error in HTTP/2 framing layer.

       93     An API function was called from inside a callback.

       94     An authentication function returned an error.

       95     A problem was detected in the HTTP/3  layer.  This  is  somewhat
              generic  and  can  be one out of several problems, see the error
              message for details.

       96     QUIC connection error. This error may be caused by  an  SSL  li‐
              brary error. QUIC is the protocol used for HTTP/3 transfers.

       XX     More error codes will appear here in future releases. The exist‐
              ing ones are meant to never change.

BUGS
       If you experience any problems  with  curl,  submit  an  issue  in  the
       project's bug tracker on GitHub: https://github.com/curl/curl/issues

AUTHORS / CONTRIBUTORS
       Daniel  Stenberg is the main author, but the whole list of contributors
       is found in the separate THANKS file.

WWW
       https://curl.se

SEE ALSO
       ftp(1), wget(1)

curl 7.81.0                     January 03 2022                        curl(1)

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转载自blog.csdn.net/a772304419/article/details/125537504