Shell

1.crash Log run-to-collapse positioningDwarfdump--arch=--lookup 0x44b79 .app.dsymAtos-arch o .app/ 0x000235f32.xcode installation path Query and settingsXcode-select-print-path #查询Xcode-select--switch #设置3. View the instruction set of the

$#, the number of arguments followed by the script runtime#! /bin/bashCase ' $# ' in 0) printf "Enter A number: " Read n= $REPLY ;; *) n=$1 ;;EsacX=$ (((1 + $n) * $n/2))echo "Tne value of 1 + 2 + 3....+ $n = $x"The

sudo uname--m View the number of operating system bitssudo uname--s display kernel name ssudo uname--r display kernel versionsudo uname--n display the network host namesudo uname--p display CPUUnder Ubuntu, text files are usually opened with the

$ represents the current process when using the Echo $$ is the PID that will output the current shell1 Echo $$ List of special variables variables meaning $ File name of the current script

1. Declaration of variablesName= "Blacksonny"　Note://variable definition does not add $, the variable and equal sign cannot have spaces betweenVariable naming rules: The first character must be a letter (a-z,a-z). You can use an

By using the Read command, you can output or perform operations after entering content from the terminal1 #!/bin/bash2#Author: Blacksonny3#Copyright (c)4 #Script follows here: 5 6 Echo " How is old is you ? " 7 Read Age 8 Echo " " $ageThe above

Code: Script_name parameter1 parameter2 Parameter3 ...It's easy to guess that the $ A is the shell script name (path) itself, and $ $ is the first argument, and so on .... you have to pay attention to the role of IFS, that is, if IFS is quoting,

Automatically back up database scripts #!/bin/bash#auto Bakcup MySQL#by 2015-7-2Bak_dir= "/data/backup/' Date +%y%m%d '"Mysql_db=discuzMysql_user=rootmysql_pw=123456Mysql_cmd=/usr/bin/mysqldumpIf [$UID-ne 0]; Thenecho "must to is use the root

#!/bin/bash#斐波那契数列#不要用递归, the depth is more than 30 old fire. functionfun_test(){if[ $ -lt 3]; Then Echo 1 return fisum1=1Sum2=1 LetCount= $-2sum=0 while[$count -GT 0]; Do Letcount-- LetSum=sum1+sum2 LetSum1=sum2 LetSum2=sum

Method One: Add debugging options when you run the script:"Usage" bash– option./shellscript.sh-e: If a command returns a non-0 exit status value (failed), exit.-N: You do not need to execute the script just to check the syntax structure and return

From Shell13 asked-E: Activate the conversion of the backslash control character (refer to the following table)-e: Turn off anti-skew control character conversion (preset)-N: Cancel line end of line symbol (with the \c character under the-e

#!/bin/shMm= ' Ps-ef|grep memcached|grep-v grep|wc-l 'While ["$MM"-eq 0]Doecho "$ (date +%y%m%d%h%m%s), the memcached is down,try to up it" >>/data/shell/men.log/usr/bin/memcached-d-u root-m 512-p 39999-c 1024Sleep 2sMm= ' Ps-ef|grep

Syntax for the FOR loop:1. For variable in value 1 value 2 value 3 ....DoProgramDoneFor example: The following script will print 4 times respectively the value of morning noon afternoon evening1 #!/bin/bash2#打印时间 3#Author mrfeng45 for-time in

1.Until Loop statement#!/bin/basha=10;until [[$a-lt 0]];d oecho $a;((a--));d one;2.case Selection Statement#!/bin/bash#auto install lamp#by 2015-6-30case $1 in          apache ) echo  "Wait for install httpd server ..." yum  install http* -y;;       

When it comes to learning about Linux and OpenStack, it's important to learn scripts well, whether it's a large-scale deployment or operation, and shell scripts are already standard.Here are just some basic notes for the Linux shell, which are noted

Manually enter a line of strings and sort them.The script is as follows:#!/bin/bash#a test about sortEcho "Please input a number list"Read -AArrs for((i=0;i${#arrs [@]}; i++)) { for((j=0;j${#arrs [@]}-1, j + +)) {if[[${arrs[j]} -GT ${arrs[j+1]}]];

#!/bin/bash#你必须知道的shell里面关于数组的操作. Arr= ("Hello" "word" "You" "is" "a" "Good" "Boy.")#arr = (' ls ') #我喜欢这个方法. Echo "-------for----------------" forIinch ${arr[@]} Do Echo $I DoneEcho "--------for---------------" for((i=0;i${#arr [@]}; i++)) {Echo

Array:A collection of a bunch of variables.Statement:Declare-a ArraynnameEach of these variables is Arrayname[index]Index starts from 0.Assignment value:Arrayname[index] = VALUEArrayname = (VALUE1 VALUE2 ...)Arrayname = ([index1]=value1

Shell Script Programming #! /Bin/bash # Fibonacci sequence # Do not use recursion. If the depth is greater than 30, it will get old. Function fun_test () {if [$1-lt 3]; then echo 1 return fi sum1 = 1 sum2 = 1 let count = $1-2 sum = 0 while [$ count-

Shell Script Programming #! /Bin/bash # Fibonacci sequence # Do not use recursion. If the depth is greater than 30, it will get old. Function fun_test () {if [$1-lt 3]; then echo 1 return fi sum1 = 1 sum2 = 1 let count = $1-2 sum = 0 while [$