Shell

There are several ways to see what shell you are currently using, and the easiest way is to use the shell's special parameters. First, a special parameter named "$$" represents the PID of the shell instance that you are currently running. This

Example 1 Typical operation, traversing all JS in the directory and using Yuicompressor compression The code is as follows Copy Code For i in ' Find Asset/v2-name ' *.js ';Todoecho "Compress $i"Java-jar

Date# Take the day beforedate-d ' 1 days ago ' +%y-%m-%d Order, E-Name, set function: (alias)Alias Ll= ' Ls-al ' Some special values$$: (for this shell PID)$!: Get the process pid of the subprocess, for example the Nohup command can get the PID$: (

Problem Description: CentOS A new user, log in after the information of the shell script is as follows: Linux CentOS Shell display-bash-4.1$ does not display the user name path solution Ps: If you mistakenly delete files in the user directory, it

Key words in the loop: Break, continue, exitBreak650) this.width=650; "src=" Http://note.youdao.com/yws/res/3245/WEBRESOURCE132ee14de25ca983e690a082c34a51f4 "alt=" Webresource132ee14de25ca983e690a082c34a5 "/>650) this.width=650; "src="

Text viewing and processing tools: WC, cut, Sort, Uniq, diff, PatchWc:word CountWC [OPTION] ... [FILE] ...-l:lines-w:words-c:bytesCutCut OPTION ... [FILE] ...OPTION:-D CHAR: Delimiter with the specified character;-F Fields: the selected field;#: The

Bash provides a number of shortcut keys, the following are the most commonly usedCTRL + A cursor moves to the beginningCtrl+e cursor moves to end of lineCtrl+l Clear ScreenCTRL + C terminating processCTRL + Z Hang up processCtrl+u Delete the

File expression-e filename true if filename exists-d filename If filename is a directory, true-F filename True if filename is a regular file-L filename True if filename is a symbolic link-r filename If filename is readable, true-W filename if

Conditional judgment, control structure:Single Branch if statementif judgment condition; ThenStatement1Statement2...FiTwo-branch if statement:if judgment condition; ThenStatement1Statement2...ElseStatement3Statement4...FiMulti-Branched if

File expression-e filename true if filename exists-d filename If filename is a directory, true-F filename True if filename is a regular file-L filename True if filename is a symbolic link-r filename If filename is readable, true-W filename if

Shell result from CmdLineecho $?If 0 then success; else failure(Shell executes each return value, RM-RF error, package cannot overwrite)Solve Sudo:sorry, you must has a TTY to run sudo  a few days ago encountered a problem, call another shell in one

Variable Description:$$The PID of the shell itself (ProcessID)$!PID of the Shell's last running background process$?End code of the last Run command (return value)$-Flag at a glance using the SET command$*All parameter lists. such as "$*" in the

First, you need to make sure that the results of the shell command execution are $0 or not 0 can only represent the execution of this statement, for example: Execute statement: ADB connect 192.168.XX. XX execution Result: Unable to connect to 192.168

#! /usr/bin/expectip_array = $ (cat /tmp/ip.txt) username = rootfor ip  in ${ip_array[*]} {                 ##### #IPspawn  ssh -p 6122 [email protected]$ $ipexpect  {"(yes/ NO)? "  { send  "yes\r";  exp_continue } "Password:"  { send  "[email 

Log-in Shell:Su–usernameSu-l usernameNon-logon Shell:SU usernameOpen Command Window under graphics terminalShell scripts that are executed automaticallyBash's configuration fileGlobal

See the shell, write a script to set the parameters of the network card try it. It's inefficient, but it's a good use.===================#!/bin/bashLang=zh_cn. UTF-8Clear #Select the network cardecho "' Date '"Echo-e "\033[34m Select Network Card

The following methods can not install the BC calculatorCreate sh fileCheck------------------------------------------------------------------v#!/bin/Bashread-P"Please enter the first number"Aread-P"Please enter a second number"Becho"and the"' Expr $a

#!/bin/Bash#defind the Pathpath=/usr/Localexport Pathread-P"Please input your first name:"Firstnamereap-P"Please input your last name:"LastNameEcho-E"\nyour name is: $firstname $lastname"#useDateCreatefileRead-P"Please input your

#!/bin/bash#a_sub () {    sleep 5}multi_thread () {    thread=5              #  define the number of threads here      tmp_fifo= "/tmp/$.fifo"     /usr/bin/mkfifo  $TMP _fifo    #  Create a new FIFO type of file     exec 6<> $TMP _fifo    /bin/rm -f 

Today, the company asked me to copy the backup files on the server to the internal server, and as long as they are up-to-date, well, what is the ideal goal of O & M personnel, that is, what can be done by computers, never do it by yourself.System: