IT Notepad

linux

Check the local public network ip

• curl ifconfig.me

[service@yfb-105-13-tx log]$ curl ifconfig.me
***.***.***.***

• curl cip.cc

[service@yfb-105-13-tx log]$ curl cip.cc
IP      : ***.***.***.***
地址    : 中国  中国

数据二  : 北京市海淀区 | ***(北京)科技有限公司

数据三  : 中国北京北京 | 电信

URL     : http://www.cip.cc/106.52.177.102

ps aux name COMMAND column with square brackets ([ ])

>>> ps aux
USE   PID %CPU %MEM    VSZ   RSS TTY STAT START TIME COMMAND
root    1  0.0  0.1 194960  9412 ?   Ss    2019 9:12 /opt/gitlab/embedded/sbin/nginx -p /var/opt/gitlab/nginx
root    2  0.0  0.0      0     0 ?   S     2019 0:00 [kthreadd]

>>> man ps
args COMMAND command with all its arguments as a string. Modifications to the 
             arguments may be shown.  The output in this column may contain 
             spaces.  A process marked <defunct> is partly dead, waiting to be 
             fully destroyed by its parent.  Sometimes the process args will be 
             unavailable; when this happens, ps will instead print the executable 
             name in brackets.  (alias cmd, command).  See also the comm format 
             keyword, the -f option, and the c option. When specified last, this 
             column will extend to the edge of the display.  If ps can not 
             determine display width, as when output is redirected (piped) into 
             a file or another command, the output width is undefined (it may be 
             80, unlimited, determined by the TERM variable, and so on).  The 
             COLUMNS environment variable or --cols option may be used to exactly 
             determine the width in this case.  The w or -w option may be also 
             be used to adjust width.

When psthe command cannot obtain the parameters of the command, psput the command in square brackets.

crontab configuration file

Common crontab commands
Print crontab configuration crontab -l
Modify crontab configuration crontab -e
crontab configuration file directory, each user’s crontab configuration is independent, the directory is as follows, the configuration file is named after the user name(不同操作系统位置稍有差异)

cd /var/spool/cron/crontabs

View page last modified time

document.lastModified

document.lastModified
"05/14/2020 16:37:00"

Open the browser developer tool and enter it under the console. document.lastModified
The return format is: dd/mm/yyyy hh:mm:ss

http returns last-modified in the header

import requests

url = '***'
header = requests.head(url)
print(header.headers.get('Last-Modified'))

>>> Wed, 06 May 2020 12:38:16 GMT

GMT indicates that the return is Greenwich Mean Time, and the conversion to Beijing time will be pushed back by 8 hours

CER certificate to PEM certificate

There are two types of CER certificates, DER (binary), Base64 (base64)

openssl x509 -inform DER -in ***.cer -out ***.pem

PEM certificate

-----BEGIN CERTIFICATE-----
MIIDpjCCAo6gAwIBAgIQNURrpb5HOrVHvbgVThsdqzANBgkqhkiG9w0BAQUFADBF
MRMwEQYKCZImiZPyLGQBGRYDY29tMRYwFAYKCZImiZPyLGQBGRYGNTAwd2FuMRYw
3assMLI4tF/5fy3vdNXWQsmFS4jKVi0w+vs=
-----END CERTIFICATE-----

nginx configuration https certificate

ssl_certificateConfigure and under the server ssl_certificate_key, where ssl_certificateis the public key file and ssl_certificate_keythe private key file, the default directory is ./conf. Configured to restart nginxnginx -s reload

server {
    
    
	listen 443;
	server_name sexyman.com;
	ssl on;
	ssl_certificate sexyman.com.crt;
	ssl_certificate_key sexyman.com.key;
	....
}

Verify https certificate public-private key pairing

Openssl extracts the information for accurate comparison, and the output information is consistent, indicating that the pairing is successful

# 对私钥操作
>>> openssl rsa -pubout -in sexyman.com.key
writing RSA key
-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAjGUZ/qbA85Y+oEYZdJeY
ItIB+8RQtX/MGvpPEVejQuB5fGFNgamH0Z1lwb524b5cVvinF9b3yQ0Hf4o1HkT6
MKki1UzZHqFoR7ZZ4eqs97qiryHHw6W4LUa3nONo6W3T2UxcENRqh3FU/hB/Tktu
ewIDAQAB
-----END PUBLIC KEY-----
# 对公钥操作
>>> openssl x509 -pubkey -noout -in sexyman.com.crt
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAjGUZ/qbA85Y+oEYZdJeY
ItIB+8RQtX/MGvpPEVejQuB5fGFNgamH0Z1lwb524b5cVvinF9b3yQ0Hf4o1HkT6
MKki1UzZHqFoR7ZZ4eqs97qiryHHw6W4LUa3nONo6W3T2UxcENRqh3FU/hB/Tktu
ewIDAQAB

postman post file

form-datakeySelect the type under the column File, don't forget to enter keythe value, otherwise the server will not get the file content

linux domain name resolution

Bind domain name-ip

configuration file/etc/hosts

127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6

10.0.1.31	ews.500.com
10.0.0.228	ets.500.com

set dns server

configuration file/etc/resolv.conf

; generated by /sbin/dhclient-script
search openstacklocal
nameserver	114.114.114.114	# 移动、联通、电信通用dns
nameserver	8.8.8.8			# google dns
nameserver	180.76.76.76	# 百度dns
nameserver	223.5.5.5		# 阿里dns
nameserver	223.6.6.6.		# 阿里dns