learning bash shell amazon

1. ENV (environment abbreviation) and export Show all environment variables 2. Description of Environment variables environment variable home" user home folder equivalent to "~" shell linux default to/bin/bash hists " ize history record number of bars mail mail the directory in which messages ar

[This is my own study notes, welcome reprint, but please specify the source:http://blog.csdn.net/jesson20121020] see how to pass parameters to a shell script today, you need to master two commands, one is the shift command, the other is getopts. Script parameter Passingshift CommandUsage:Shift n Shifts the parameter position to the left n bits at a timeIf we want to implement the statistics of the total number of files, we can use this shift

often configures a long directory name (to avoid forgetting), But changing the directory is a hassle. At this point, Brother Bird is accustomed to using the following way to reduce the issue of the command issued wrong: [[email protected] ~]# work= "/cluster/server/work/taiwan_2005/003/" [[Email protected] ~]# CD $work future I want to use a different directory as my mode working directory, just change work this variable! And this variable can be directly specified in t

out the last/and left string: my.file.txt${file#*.} Take out the first one. And the string to the left: file.txt${file##*.} Take off the last one. And the string to the left: txt${file%/*} take out the last/And right string:/dir1/dir2/dir3${file%%/*} take out the first/and the right string: (null value)${file%.*} take off the last one. And the string to the right:/dir1/dir2/dir3/my.file${file%%.*} take off the first one. And the string to the right:/dir1/dir2/dir3/myTest.sh:File=dir1/dir2/dir3/

red output Hello world. 　　2. Define the script:A, create a hello.sh text file;b, and then start with #!/bin/bash, where the declaration of the script must be added.c, output instructions. The # in the instruction indicates the meaning of the comment.Cases:#!/bin/bash#myFirst program! Echo " \e[1;31mhello wolrd\e[0m"　　3. Execute scriptA. Execute scripts directly using

To see what versions of the Shell:cat/etc/shells system are currently running, the first process that starts is initHow bash Shell debugs:Simply add parameters after the SH command-N: Do not execute scripts, query the grammar within the scripts, if there are errors are listed!-V: The contents of scripts are displayed on the screen before executing the scripts;-x: The scripts content that will be used is dis

; file 2 #把正确的输出追加到文件1中, append the wrong output to file 2Enter redirection:WC [options] [filename]-C: Statistics of bytes-W: Count the number of words-L: Count rowsSequential execution of MULTIPLE commands:Command 1; command 2 #度命令顺序执行Command 1 command 2 #当命令1正确执行, command 2 does not executeCommand 1 | | Command 2 #当命令1执行不正确, command 2 does not executeExample: Command echo yes | | Echo no #命令正确执行输出yes, error execution output noPipe character:Command 1 | Command 2 #命令1的正确输出作为命令2的操作对象Wildcard c

True when string str1 and str2 are not equal-N str1 True when the length of the string is greater than 0 (string non-null)-Z str1 True when the string length is 0 (empty string)STR1 is True when string str1 is not empty2, the number of the judgmentInt1-eq int2 Two numbers equal to TrueInt1-ne Int2 Two number is trueINT1-GT Int2 int1 greater than Int2 is trueInt1-ge Int2 int1 greater than or equal to Int2 trueInt1-lt Int2 int1 Less than Int2 is trueInt1-le Int2 int1 less than or equal to Int2 tr

行脚本参数的个数Echo '$*='$* #所有参数变成一个字符Echo '[Email protected]='[email protected] #所有参数basename$0 #获取文件名dirname$0 #获取文件的目录[email protected] sbin]#SH/usr/local/sbin/test.SHAA bb$0=/usr/local/sbin/test.SH$1=aa$#=2$*=AA Bb[email protected]=AA bbtest.SH/usr/local/sbinProcess state variables$? Gets the return value that executes the last command (0 is successful, others are failed)$$ getting the PID of the current shell$_ gets the last parameter of the previous c

Tags:tty a regular expression devproject passwd regular penwho #!/bin/bash-#echo do what exetuate this project \nprintf "Please input your passwd" Stty-echoread Pass Shell Scripting Learning-2

Parameters:-N does not execute script, only checks syntax for errors-V Output the script contents to the screen and execute the script-X executes the script and outputs the content to the screen-N-VTen module () { eval '/usr/bin/modulecmd bash $*'}#/bin/bashif [$15 ];then "Yes"or "else" No " Fiyes-X[[Email protected] sbin]# SH-'['5']' 2operator expected+ echo NonoExpand:Use PS4 to make debugging output line numbers[[email protected] sbin]#

-decrement is no problem.Echo $ ((--STR))12Echo $ ((--STR))11Echo $ ((++str)) #结果正常12Echo $ ((++STR))13Echo $ ((--STR))12You can also use [].echo $[str= $str +6] #在 [] Use the variable symbol $18Echo $[str=str+6] #[] does not use the $ symbol24However, if $[$str =str+6] or $[$str = $str +6] An error will occur.echo $[$str =str+6]-bash: 24=str+6: Attempted assignment to Non-variable (Error token is "=str+6")echo $[$str = $str +6]-

corresponding child shell. It is also necessary to restart or use the source ~/.bash_profile to make the call to take effect.The read and invoke process for bash is briefly described here:Login Linuxè Read/etc/profile--> read the corresponding user's. bash_profile or. Bash_login or. Profile (priority is reduced from front to back, so there are three kinds of files that are reserved for different Linux tran

"Please input your score:" Aif ((a Thenecho "You didn ' t pass the exam."fi5.1 with the Else instance code is as follows#!/bin/bashread-p "Please input your score:" Aif ((a Thenecho "You didn ' t pass the exam."Elseecho "good! You passed the exam. "fi5.2 with Else if (this is the argument in C) is represented in the shell as Elif#!/bin/bashread-p "Please input your score:" Aif ((a Thenecho "You didn ' t pass the exam."elif ((a>=60)) ((a Thenecho "go

Login Host: Native Login (7 interface Tty1~tty7) Text Interface (TTY1~TTY6) Graphical Interface (TTY7) Telnet wildcard characters: *: Represents an arbitrary string, which can be an empty string ？ : Represents a character, but cannot be empty escape character : \line continuation symbol : \Character Set : [A-z]: English Small Letter [A-z]: English capital letters [A-za-z]: English case letters [0-9]: Number [a-z

Tags: learning recordMeaningless script, big God do not spray/[[emailprotected]desktop]#vimoraclesh.sh #!/bin/bash Clear #函数 test_parameter1 () {' echo ' su-oracle-c ' sqlplus/nolog ' This article is from the "One Meter Sunshine" blog, please be sure to keep this source http://sunshine3.blog.51cto.com/3988340/1703840A little bit of learning

cycleFormatUntil commandDoStatement (s) to being executed until command is trueDoneExit Loop: Break, continueNote:(1) in a nested loop, break n means exiting the nth layer loop and counting from the inner layer.(2) Continue exits the current loop.Nine,shell function Delete function: $unset. f function_name When n>10 need ${n} to obtain parameters, n X. input/Output redirection(1) > (or (2) >> (or Xi.Shell file containsThe

function. Like what: 1 #!/bin/bash 2 hello () { 3 echo "My name is Xu Hao" 4} 5 6 #调用上面的函数 7 Hello Run Result: root@iz28t5k4ny4z:/usr/xiho/shell#./06.sh my name is Xu Hao calling a function requires only the name of the function and does not require parentheses. Let's look at a function with the return statement: After t

Shell learning-awk getting started I. awk application scenarios Format data or extract records from a large text file Ii. Usage Command Line$ Awk [-F field-separator] 'commands' input-file (s)Commands is a real awk command[-F domain delimiter] is optional. If no-F option is available, awk uses space as the Separator by default. If the domain separator is not a space, for example, to browse ": the-F option m

#!/bin/bash############################################################### File Name:/server/scripts/maopaopao.sh# version:v1.0# Author: Cattle Farming# Created time:2017-09-20 19:44:10# Description: Bubble sort# Read Instructions:# 1, read-a shuzu-a indicates that the next input is an array Shuzu is the array name set# 2, ${#. [@]} The number of elements representing the array# 3, ${. [@]} Represents all elements of an array# 4 、.. [A] represents the