linux shell scripting cookbook

From a programmer's point of view, the shell itself is a program written in C language, from the user's point of view, the shell is the user and the Linux operating system communication Bridge. Users can either enter command execution and use shell scripting to accomplish mo

First part: Linux command line"Linux command line and Shell Scripting Encyclopedia" chapter I: the first knowledge of Linux shell"Linux command line and

1#!/bin/Bash2 ############################################3# @content Chapter8,9of Linux Command line and Shell Scripting Bible4 # @reader Gavin5# @date the/ A/ -6 ############################################7CHAPTER88 9+user varriable make the shell A-computer programTen 1when assigning a value to a user-defined v

$name >/dev/nullif [$?-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

PS1 = "[\t][\u]\$"//New shell prompt shows the current time and user nameIn Windows, you often see such file paths: D:\work\FTL Moniqi\ftl_lru-0513\ftl_lru-0513\siLinux takes a different approach. Linux stores files in a single directory structure, a directory that we call virtual directories. The virtual directory contains the file paths for all storage devices installed on the PC.Linux uses the forward sl

-50.png "alt=" Wkiol1mdkm2jz6uoaabbjl5wdhm575.png "/>650) this.width=650; "src=" Https://s4.51cto.com/wyfs02/M00/00/D0/wKiom1mdk6ihkQAmAAAUhdjoX-o745.png "style=" float : none; "title=" screenshot from 2017-08-23 22-38-48.png "alt=" Wkiom1mdk6ihkqamaaauhdjox-o745.png "/>650) this.width=650; "src=" Https://s4.51cto.com/wyfs02/M02/9F/80/wKioL1mdk56TXfZHAAATseIwAOw478.png "style=" float : none; "title=" screenshot from 2017-08-23 22-39-10.png "alt=" Wkiol1mdk56txfzhaaatseiwaow478.png "/>15. Queryin

$name >/dev/nullif [$?-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

:07Variables in shell scripts You should use a variable instead when you use a string more frequently in your script and the string length is long When using conditional statements, variables are often used?? If [$a-gt 1]; Then ...; Fi When referencing the result of a command, replace it with a variable?? n=wc -l 1.txt When writing scripts for user interaction, variables are also necessary?? Read-p "Input a number:" N; echo $n?? I

to customize their command aliases and private script functions3. non-interactive shellThis is the shell used by the system to execute shell scripts.There is no command line prompt.Bash shell provides bash_env environment variables. When a non-interactive shell is started, bash_env is checked to see the startup file t

Often, when people refer to the "Shell scripting language", they are bash,ksh,sh or other similar Linux/unix scripting languages emerging in their minds. Scripting languages are another way to communicate with a computer. Users can move the mouse and click on a variety of ob

directly behind the. BASHRCfunction Addem{Echo $[$ [+ $]}This function is used anywhere on the system.2. Reading function filesYou can use the source command to add a function from the library file to the. BASHRCAdd it directly behind the. BASHRC. /home/xcy/myfuncsSo you can use the function inside the Myfuncs.17.8 exampleThis section describes the GNU Shtool Shell script function library. The Shtool library provides a few simple

The first part of the Linux command lineThe 1th chapter of the first knowledge of Linux she1.1 What is Linux 21.1.1 Deep Dive into Linux kernel 31.1.2 GNU Tools 61.1.3 Linux Desktop Environment 81.2 Linux Release 121.2.1 Core

echo "Top Ten Disk Space Usage" echo "for $CHECK _directories Directory" For Dir_check in $CHECK _directories Do echo "" echo "The $DIR _check Directory:" Du-s $DIR _check 2>/dev/null | Sort-rn | Sed ' {one, $D; =} ' | Sed ' N; s/\n//' | Gawk ' {printf $ ': "\ T" $ "t" $ "\ n"} ' Done Exit [Email protected]:~/shell/24zhang$ Run:./big_user.shOnly two directories/var/log/home are specified above, and the generated rep

Basics of Linux Shell scripting here we first talk about the shell of the basic syntax, the beginning, comments, variables and environment variables, to do a basic introduction, although not related to specific things, but lay the foundation is to learn easily after the premise. 1.

1. Linux Scripting Basics1.1 Basic Introduction to grammar1.1.1 StartThe program must start with the following line (must be placed on the first line of the file):#!/bin/shThe symbolic #! is used to tell the system that the parameters behind it are the programs used to execute the file. In this example we use/BIN/SH to execute the program.When you edit a good script, you must also make it executable if you

command. You can use Echo to print any variable value in any place where you suspect it is wrong. That's why most shell programmers spend 80% of their time debugging programs. of the Shell programThe advantage is that there is no need to recompile, and it does not take much time to insert an echo command.The shell also has a real debug mode. If there is an error

[Turn]http://www.knktc.com/2011/08/20/linux-shell-expect%e6%89%b9%e9%87%8fscp%e8%84%9a%e6%9c%ac%e5%b7%a5%e5%85%b7/ One of the most recent tasks in preparing a deployment is to send some files, such as installation packages, to a large number of servers. Although there is already a Brother Woo script available: A Python script written by the SSH and SCP features provided by the Paramiko module. But I'm stil

be output to the monitor while redirecting files, but generally overwrite the original file content, you can use the-a append contentCode 5-23[Email protected]:/data# date | Tee Textmon Dec 5 06:18:04 CST 2016[email protected]:/data# cat text Mon Dec 5 06:18:04 CST 2016[email protected]: /data# who | Tee text root pts/0 2016-12-05 04:26 (122.90.143.21) [email protected]:/data# cat text root pts/0 2016-12-05 04:26 (122.90.143.21) [Email protected]:/data# date | Tee-a text

used with variable names, and if the loop body does not include a variable name, a dead loop may occurHow the list is generated:1) Give a direct2) List of pure integersSEQ: Output An integer listseq [First [INCREMENT]] Last3) curly braces unfold{first.. Last}4) return value of the execution result of the command5) GLOBBING6) references to certain variables: [email protected], $*Features of the For loop:1. There is almost no cycle of death;2. The entire list needs to be loaded into memory during

TopicShell Scripting Knowledge points: What are trap signals in Linux system scripts and how are they used?Reference answer: "Trap signal Command description"The trap command is used to specify the actions to be taken after a signal is received, and a common use of the trap command is to complete the cleanup work when the script is interrupted.Historically, the shell