linux shell scripting tutorial for beginners

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

, The interpreter (interpreter) needs to read the source code that we wrote and convert it to the target (object), which is then run by the computer. Because each execution of the program is more than the compilation process, so efficiency has decreased.The advantage of using scripting languages is that they are mostly run at a higher level than the compiled language and can easily handle objects such as files and directories, and the disadvantage is

$name >/dev/nullif [$?-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

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

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script rotatefile can solve this problem. This script can rename the message to save the file (assuming outmail) is OUTMAIL.1, and for outmail.1 it becomes outmail.2 and so on ... The code is as follows: #!/bin/sh # vim: set sw=4 ts=4 et: ver="0.1" help() {   cat How does this script work? After detecting a file name provided by the user, we perform a 9 to 1 loop. File 9 is named 10, file 8 is renamed to 9, and so on. After the loop is complete, we name the original file 1

# input Check:If [-Z ']; ThenError "Error:you must specify a file, use-h for help"FiFilen= "$"# Rename any. 1,. 2 etc File:For N in 9 8 7 6 5 4 3 2 1; DoIf [-F ' $filen. $n "]; Thenp= ' expr $n + 1 'echo "MV $filen. $n $filen. $p"MV $filen. $n $filen. $pFiDone# Rename the original file:If [-F "$filen"]; Thenecho "MV $filen $filen. 1"MV $filen $filen. 1Fiecho Touch $filenTouch $filenHow does this script work? After detecting a file name provided by the user, we perform a 9 to 1 loop. File 9 is na

: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

Shell Getting Started Tutorial (1)-shell-JUSTKK's Column-Blog channel-csdn.nethttp://blog.csdn.net/justkk/article/details/43795131 Shell Getting Started Tutorial (2)-Variables and Parameters-JUSTKK-Blog channel-csdn.nethttp://blog.csdn.net/justkk/article/details/44081993

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

Use PHP as the Shell scripting language. We all know that PHP is a very good dynamic web page development language (fast speed, short development cycle ......). However, only a few people realize that PHP can also be well written. we all know that PHP is a very good dynamic web page development language (fast speed, short development cycle ......). However, only a few people realize that PHP can also be a g

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

As we all know, PHP is a very good dynamic web development language (fast, short development cycle ...). ）。 But only a very small number of people realize that PHP can also be very good as the language of writing shell scripts, when PHP as the language of writing shell scripts, he is not as powerful as Perl or bash, but he has a good advantage, Especially for those of me who are familiar with PHP but are no

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

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

How to use PHP as a Shell scripting language. We all know that PHP is a very good dynamic web page development language (fast speed, short development cycle ......). However, only a few people realize that PHP can also be well written as S. We all know that PHP is a very good dynamic web page development language (fast speed, short development cycle ......). However, only a few people realize that PHP can a

As we all know, PHP (as the current mainstream development language) is a very good dynamic web development language (fast, short development cycle ...). ）。 But only a very small number of people realize that PHP (as the current mainstream development language) can also be very good as the language of writing shell scripts, when PHP (as the current mainstream development language) as the language of writing shell