best shell scripting book

Linux shell scripting:1. Program Structure Exercise: Write a script, given a positive integer, to calculate the sum of all digits of this number.For example, if the program is given input 123, it should return 1+2+3=6.2. Program Structure Exercise: Write a script, given a positive integer, to output this number in reverse order.For example: program input 123, then should output 321.3.Linux Command +

How to protect a shell program you've writtenTo protect your own shell scripting program, there are many methods, the simplest way there are two: 1, encryption 2, set the expiration time, following the SHC tool as an example description:I. Download and install the SHC toolSHC is a tool for encrypting shell scripts. Its

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

"array is:" ${lengthn}#Shell Pass Parametersecho "Executed file name: $"echo "First parameter: $ $"echo "The second parameter is: $"#Shell operator: Native bash does not support simple math operations, but can be implemented with other commands, such as awk and expr,expr, which are most commonly used.#expr is an expression calculation tool that uses it to perform the evaluation of an expression.#算数运算符Val=

1.Shell command line writing rules:Multiple commands can be executed on a command line, but required;Long command statements can be expanded with \ on the command line2. Execute Shell Program2.1./test.sh2.2 Bash test.sh2.3 In order to compile and execute the shell-written program in any directory, add the/bin directory to the entire environment variableExport Pat

shell and returns the given valueIn general, exit 0 means that the program ends normallyIf exit is not a value of 0, the program produces an error.In the case of the shell, after calling your program in the shell, use echo $? command to see the exit value of your program. In a shell script, it is usually based on the

Shell Scripting Study Guide Mechanical industry publishing ISBN 987-7-111-25504-82nd Chapter2.4Primary traps1. Today's systems, for #! The length limit for this line is from 63 to 1024 characters, try not to exceed 64 characters.2. On some systems, the command-line section contains the full path name of the command. Some systems do not, however, and the command line part is passed to the referenced program

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

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

-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