learning bash shell amazon

Shell script learning and shell script1111111111111 clear the simple command script of the messages log file under/var/log/Var/log/the system file under the log file must have the root permission:$ UID is the global variable of the system:Make make install indicates that the previous step is successful.Make | make install indicates that the previous operation is

,/sbin,/usr/ Bin,/usr/sbin wait in path, your current directory is usually not in path, so write mayuan.sh will not find the command, to use. /mayuan.sh told the system that it was looking in the current directory. As shown in the following:2. As an interpreter parameterThis works by running the interpreter directly, whose parameters are the file names of the shell scripts, such as:/bin/bash mayuan.shThe sc

Linux learning-shell simple writing-shell It is recommended that all scripts be stored in/usr/local/sbin. Run the sh-x script. sh-x to view the execution process. 1. When using a variable in a script, use the $ symbol: #! /Bin/bash # Assign a value to a variable using reverse quotation marks D = 'date + "% H: % M: % S

bash_rematch[] array #re1.sh#!/bin/bash# manage to know your nameread-p "Please input your fullname:" Nameif [[$NAME =~ (. *) [[: Space:]] (. *)]];thenecho "Your last name ${bash_rematch[2]}" echo "Your name is ${bash_rematch[1]}" echo "Full name ${bash_rematch[0 ]} "fi execution results [[email protected] shell]#./re1.sh Please input your Fullname:liancao Liu your surname Liu you call liancao full name Li

NOTES: # Note: The # in #!/bin/bash at the beginning of the shell file is not a comment run: 1, bash shell.sh 2, chmod +x shell.sh./shell.sh 3, add to Path change Amount of 4,. ./shell.sh Troubleshooting: 1, syntax error when running with prompt 2, logic error using echo printing, Sleep Number: Sleeping number seconds, reduce the cycle speed using

load bash-related configuration files (typically the Non-login Shell's ~/.BASHRC) and execute bash to enable our commands to execute. Otherwise the program will not know what shell to use.The environment variable is set here so that the program can execute some external commands directly while it is in progress, without having to write absolute paths.The last li

: #!/bin/bash # Calling one function from another Number_one () { Echo "Url_1 is http://see.xidian.edu.cn/cpp/shell/" Number_two } Number_two () { Echo "url_2 is http://see.xidian.edu.cn/cpp/u/xitong/" } Number_one Operation Result:Url_1 is http://see.xidian.edu.cn/cpp/shell/Url_2 is http://see.xidi

$name >/dev/nullif [$?-eq0];thenstr= "user${name}isdeletesuccessfully!!!" echo-e "\033[30;47m$str\033[0m" elsestr= "user${name}isdeletefailly!!!" echo-e "\033[31;47m$str\033[0m" fi ;; 5) str= ' df-th ' echo-e "\033[30;47m$str\033[0m";; 6) str= ' free -m ' echo-e "\033[30;47m$str\033[0m" ;; 7) clearmenu;; 8) echo-e "\e[31mlogout...\e[0m" sleep1break;; NBSP;NBSP;NBSP;NBSP;NBSP;NBSP;NBSP;NBSP;NBSP;NBSP;NBSP;NBSP;NBSP;NBSP;NBSP;NBSP;9) echo-e "\e[31mquitsuccessfully!!! \e[0m " exit;; *) str= "I

the function return value.Let's look at an example:#!/bin/bash# Define your function Herehello () {echo "Url is http://see.xidian.edu.cn/cpp/shell/"}# Invoke your Functionhe LloOperation Result:$./test.shhello world$The calling function only needs to give the function name, and no parentheses are required.Then look at a function with a return statement:#!/bin/bashfunwithreturn () {echo "The function is to

command line parameters, we can use the following way to traverse it, but usually we prefer to use "[email protected]", because it can be in the command line parameters within the space when it distinguishes it6. Variable $ #用于统计命令行参数的个数:7, the default value of the variable: 1) b=${a:-"xxx"} means if the variable a is not set or the value is empty, then b= "xxx", 2) with:-The symbol is different ${a:= "xxx"} means if a is not set or is empty, then a is set to ' xxx ' and return the value "XXX",

#ch #!/bin/sh mod +x filename Cho *.jpg∪ slow Teman tip Wine together Ltd U Chung Yuen oldest? /filename to execute your script. This will print out the results of "mail.jpg tux.jpg". quotation marks (single and double quotation marks) prevent this wildcard extension: #!/bin/sh echo "*.jpg" Echo ' *.jpg ' This will print "*.jpg" two times. Single quotes are more restrictive. It prevents any variab

Open a text editor, create a new file with the extension sh (sh for Shell), and the extension does not affect script execution.Enter some code: #!/bin/bash echo "Hello world!" "#!" is a contract tag that tells the system what interpreter the script needs to execute, even if it uses a shell. The echo command is used to output text to a window.The

2 3 Do For var2 in 0 5 Do if [ $var 1 -eq 2-a $var 2 -eq 0 ] /c0> Then break 2 Else Echo "$var 1 $var 2" fi Done Done As above, break 2 means to jump out of the outer loop directly. Operation Result:1 01 5Continue commandThe continue command is similar to the break command, with only a little difference, and it does not jump out of all loops and just jumps out of the current loop.To modify the above example: #!/bin/bash