Linux command Daquan linux command reference: https://man.linuxde.net/
three of the awk = "Aho Weiberger and Kernighan" the first letter of the last name, awk is a programming language, and for processing text data in linux / unix.
bash = GNU Bourne-Again Shell mostly Linux default shell
bc = Basic Calculator basic calculator, an arbitrary-precision calculator language support interactive execution.
bg = BackGround for the job to run in the background, the foreground can perform other tasks.
fg = ForeGround for background job (or run in the background in the background suspended job) into the foreground terminal runs.
cal = calendar calendar followed by the number of months, years to display the specified number of calendar months
rpm = RedHat Package Manager RedHat Package Management Tool
tar = tape archive can put a bunch of files and directories all packaged into one file
chgrp = Change group changing file ownership user groups
chmod = Change permissions mode to change the file or directory.
chown = Change owner to change the owner and group of a file or directory belongs, this command can authorize a user so that the user becomes the owner of the specified file or set of files that change belongs.
logname = login name displays the current logged-on user name
passwd = PassWord used to set user authentication information, including the user password, password expiration time.
su = switch user identity of the current user to switch to a different user, the user must enter the account number and password to be changed when changing.
sudo = super user do to any other capacity to execute the command, the default identity for the root.
w = who has landed for displaying a list of users of the system, and the user is performing display instruction.
whoami = whoami for printing the currently valid user name corresponds to execute id -unthe command.
chsh = change shell for replacement when the shell used in the system log.
chfn = change finger information finger command to change information displayed.
chroot = change root directory to run in the specified root instruction.
chkconfig = check config inspection, various services of the system. chkconfig not immediately activate automatically disabled or a service, it simply changes the symbolic link.
cd = Change Directory Change directory
pwd = print working Directory displays the user's current working directory to the absolute path of the way.
pushd = push Directory command is added to the directory stack. If the instruction does not specify a directory name, it will be the current working directory into the top of the directory stack.
popd = pop Directory record for deleting the directory stack; if the popd command without any parameters, will first delete the directory uppermost recording stack, and then change to the directory stack after the deletion of the uppermost directory.
dirs = directories displays all the records in the current directory stack (dirs command without parameters to display the current record in the directory stack)
cp = copy Copy
rcp = remote copy remote copy between two Linux host file copy operation easier
scp = secure copy commands for the remote copy of the document under Linux, and scp transmission is encrypted.
ln = link files used to create the connection member, the connection type and the symbols into hard links connecting the two, the default type is a hard-wired connection.
ls = list to the target list showed higher usage command in Linux.
rm = ReMove delete a directory one or more files or directories can also be a directory and its subdirectories subordinate all files are deleted.
rmdir = Remove directory to delete empty directories.
cat = catenate connection file and print to standard output, cat often used to display the contents of the file.
nl = Number of Lines read parameter file (standard input by default), the line number in the input is calculated, the calculated number of lines written to standard output.
sed = Stream Editor stream editor, to check itself, both sides of the match to have the character CMD @
fmt = format read the contents of the file, a simple optimization processing according to the settings of the file format options, and the results sent to the standard output device.
printf = Print Format format and outputs the result to standard output.
exec = execute commands for calling and executing instructions.
grep = global search regular expression (RE) and print out the line full regular expression search and print out the line
egrep = Extended GREP used to find the file in the specified string.
pgrep = process grep name based on the discovery process from the run queue in the process, and displays the found process id.
df = Disk Free disk space can be used for display on the disk partition.
hdparm = hard disk parameters used to read and set parameters IDE or SCSI hard disk.
du = Disk Usage is to look at the files and directories on the disk space used
iostat = in out status for monitoring system input and output devices use the CPU.
Process status ps = Processes Status report for the current system, use this command to state what processes are running and running can determine, whether the end of the process, there is no rigid process, which process takes up too many resources and so on.
pstree = process status tree to tree view mode to show the derivation of the relationship between processes, display more intuitive.
lsof = List Open Files to view the files you open play process, the process of opening the file, the process of open ports (TCP, UDP).
man = help instructions at Manual Linux, you can view the Linux command through the man command help, help, and configuration files and other information programming help.
mkfs = make file system is used (typically the hard disk) to create a Linux file system on the device. mkfs itself does not establish the implementation of the file system, but to call the relevant procedures to implement.
mkbootdisk = make boot disk to create a single system can be used for the currently running system boot diskette to be able to start operation at the appropriate restoration system failure.
Integrity e2fsck = ext2 file system check is used to check a second extended file system, through appropriate option to try to fix the errors.
ftp = File Transfer Protocol commands used to control the way to transfer files between local and remote machines.
tftp = trivial file transfer protocol by using the TFTP protocol for transferring files between the machine and the tftp server.
ping = Packet InterNet Grouper to test network connectivity between the hosts.
ssh = Secure Shell openssh suite of client connectivity tools, you can give ssh encryption protocol for secure remote login server.
rlogin = remote login used to log in to a remote Linux terminal from the current host.
rsh = remote shell to connect to the specified remote host and executes the specified command.
arpwatch = ARP watcher to monitor the recording arp network.
apachectl = Apache control interface is the Apache Web server front-end control tools to start, shut down and restart the Web server process.
wc = Word Count for calculating numbers. Using the wc command we can calculate the file number Byte, words or the number of columns, without specifying the file name or file name is given, "-", the wc command to read data from the standard input device will be.
sync = synchronize content for forcibly changed immediately written to disk, super-block update information.
xargs = eXtended ARGuments other commands to pass a filter parameter is a combination of a plurality of tool commands. It excels converts input data into a standard command line parameters, xargs or stdin pipe capable of processing and converts it into a command specific command parameters.
wall = write all open for outputting information on all the terminals to the current system.