shell scripting basics

Tag: The grep command of the Shell scripting toolgrep (abbreviated from globally search a Regular expression and Print) is a powerful text-search tool for Linux systems that can search for text using regular expressions , and print out the matching lines. Egrep and Fgrep are grep extensions that support more re- metacharacters ,fgrep is fixed grep or fast Grep.linux uses the GNU version of Grep, which is mo

How to build a archive file using shell scripting and export the signed IPA file.1. Build Script DescriptionThis shell script is used for Build,xcode workspace source code engineering and is exported as a re-signed IPA file for distributing test installation files and files for submitting AppStore audits. Implement auxiliary product development, test configuratio

tasks, you need to include the if/then criteria to judge. Shell scripting supports such operations, including comparison operations, determining whether a file exists, and so on.The basic if Condition command options are:-eq-compare two parameters for equality (for example, if [2–eq 5])-ne-comparison of two parameters is not equal-lt-parameter 1 is less than parameter 2-le-parameter 1 is less than or equal

big side.Listen to the old boy teacher and some experts said that the best way to learn early is to knock and break the problem of practice.The highest programming self-perception is:Problem analysis decomposition is fast and complete.Completeness: is to judge the various possibilities.High efficiency, high performance, 1+2+3...+100 = (1+100) * (100/2)/2Old boy Shell advanced programming combat Video 52 freeHttp://edu.51cto.com/course/course_id-963.h

file Content:bin:x:2:2:bin:/bin:/usr/sbin/nologin　　The done command is useful for looping the results of a loop to another command, redirecting to a file or screen, and using other commands to display to the screen[Email protected]:/data# cat Demo7 #!/bin/bashfor State in ' North Dakota ' Connecticut Illnois Alabama Tennesseedo Echo "$state is the next place to go" done | Sort > Textecho "This completes we travels" [email protected]:/data#./demo7 This completes our travels[email protecte

Bit left shift >> Bit right Shift Bit Boolean and | Bit Boolean or Logic and || Logical OR Code 2-11[Email protected]:/data# cat Demo3 #!/bin/bashval1=10if (($val 1 * * 2 >) then ((val2= $val 1 * * 2)] echo "The sq Uare of $val 1 is $val 2 "Fi[email protected]:/data#./demo3 the square of 100　　use both brackets[[Expression]] provides another feature

子这里定义一个全局变量hobby[[Email protected] ~]# exit #退出, go into Dad's bash environment[Email protected] ~]# echo $hobby #爹是看不到儿子的export的, son's son can seeJob Two: awk text processingPrint user names for UID within the 30~40 rangePrint the line number and user name of the 第5-10 linePrint odd linesPrint even rowsPrint a row with a number of fields greater than 5Print uid Not equal to GID usernamePrint a user without a shell specifiedJob Three:

Tags: shell multi-line redirection1. What is the problem requirement?First, the need to come from, mainly to write shell script, with cat for multi-line input redirection, the Terminator must be hyphenation first, the format is not good-looking.2, how? How to solve this problem?First Baidu, Google search the next, the result is to say that more is the shell multi

-nand 11 use, tell read command to accept single word specifier exitCode 2-25[Email protected]:/data# cat Demo5 #!/bin/bashread-n1-p "Do you want to continue [y/n]" Answercase $answer in y|y) E Cho echo "fine,continue on ...";; N|n) echo echo "Ok,goodbye" exit;; Esacecho "This is the end of the script" [email protected]:/data#./demo5 does you want to continue [y/n]yfine,continue on]. . This is the end of the script　　Hidden mode read, the-S optio

equal to [-X $file] Determines whether the $file exists and has executable permissions, and the same-R test file readability [-N "$a"] determine if the variable $ A has a value, test the empty string with-Z ["$a" = "$b"] determine whether the value of $ A and $b are equal [Cond1-a Cond2] to determine whether Cond1 and Cond2 are also established,-o means cond1 and Cond2 have a set up Be aware of the spaces in the Condition Test section. there are spaces on both sides of the square brackets, and

Recent project requirements, need to write some shell script interaction, the pipeline is not enough time, expect can be very good to implement the interaction between the script, search for information, found that many articles on the Web are reproduced, I think this article is also good, so simple changes to take over and share with you ~1. Expect isSpawn: Add the shell commands you need to execute, such

to the right of the symbol.3. Expand your knowledge The Shell can represent the result of a command, usually assigning a value to a variable, such as the following command: # n= ' Wc-l/etc/passwd | awk ' {print '} ' # echo $n Date also has many uses, for example: date +%h # hours 21date +%m # minutes 48date +%s # seconds 48date +%t # time 21:49:04date%w # Week 0 # from 0 Start, representing Sunday date-d "-1 day" +%f # me

????????echo?"$username?已经登录"????????echo?"fuck?,go?out?my?system"?|?write?$username????else????????echo?"$username?已经下线"????fi????sleep?3done}21, randomly generated within 10 of the number, to achieve the word guessing game, the hint is relatively large or small, equal to exit#!bin/bashlim=10let?key=$RANDOM%limread?-p??"please?input?a?number?less?than?$lim:?"?numuntil?false;do????if?[?$num?-le?$lim?>?/dev/null??]??[?$num?-ge?0??>?/dev/null?]?;then????????if?[?$num?-lt?$key?];then????????????rea

Processing of parameter processing-shell incoming parameters $#The number of arguments passed to the script $*Displays all parameters passed to the script in a single string. Unlike positional variables, this option parameter can be more than 9 $$The current process ID number for the script to run $!Process ID number of the last process running in the background [emailprotected]With the $# same, but quoted when used, and retu

First, Background introductionDBA Daily Update Insert|update More, delay a lot of time. The development of tools, although the user password in the script encryption and strict operation, but carefully query internal logic or may reveal the password, today, using Gzexe method to encrypt the shell script.Second, start testing1. Find a test script to execute. (The online script content is inconvenient to publish, write the test script yourself.) ）　　2. E

contents):Real 3m41.864suser 0m34.224ssys 0m2.102sSo efficiency is barely acceptable.Test of Method Two:Time Awk-f awkfile datafileResults (omission of file contents):Real 2m26.487suser 0m7.044ssys 0m1.371sEfficiency is significantly better than the first one.Then examine the efficiency of method three:Time awk ' Begin{srand ()}{b[rand () nr]=$0}end{for (x in B) print b[x]} ' dataResults (omission of file contents):Real 0m49.195suser 0m5.318ssys 0m1.301sIt's pretty

/functionsport=3306User= "Root"Bindir= "/application/mysql/bin"Datadir= "/application/mysql/data"Mysqld_pid_file_path= "/application/mysql/' hostname '. pid"Path= "/sbin:/usr/sbin:/bin:/usr/bin: $basedir/bin"Export PATHReturn_value=0# Lock directory.Lockdir= '/var/lock/subsys 'Lock_file_path= "$lockdir/mysql"Log_success_msg () {echo "success! [Email protected] "}Log_failure_msg () {echo "error! [Email protected] "}Start () {# Start Daemonecho "Starting MySQL"If Test-x $bindir/mysqld_safeThen$bin

not need to back up the Data= ' tail-1 $filename ' if[ $data "== "$comparedata" ];then echo "' Date ' rmanbackupsucess" >>/ops/tarlog else echo "' Date ' Rmanbackup Fail "NBSP;AMP;GT;GT;NBSp;/ops/tarlog exit2 fi #tarbackupfileandmoveto Backupserver #将当天的备份集压缩备份出来并move至对应nfs提供的文件夹, my 300GB backup compressed as long as 30 g, compression ratio is still very amazing/usr/bin/find/mnt/rman- name ' oradb1* ' >/ops/tarlist foriin '/bin/cat/ops/tarlist ';d o echo ' Date ' tar $i start >>/ops/tarlog

Overview:Overview:This section describes the array of shell scripting in Linux, advanced string processing, advanced variables, and configuring the user's environment.One, function and positional parameter extension1. TheShift command implements the jump in the position parameter, which squeezes the leftmost parameter650) this.width=650; "src=" Http://s1.51cto.com/wyfs02/M01/86/5B/wKiom1e9EFvAun-AAABG0xL4ac

;NBSP; value2= "fossmint.com" NBSP; if[ "$value 1" = "$value 2" NBSP;] 7, use $ (command) to do substitution command substitution is replacing the command itself with the output of this command. Use $ (command) instead of quotation marks ' command ' to do the command substitution. This is also recommended by the Shellcheck tool, which displays warnings and recommendations for Shell scripti