how to learn unix shell scripting

1, #!/bin/shThe first line tells the operating system that the interpreter for this script is/bin/sh this executable file2. While loop:#!/bin/shSleep 1; echo "User"; \Sleep 1; echo "Password"; \While true; Do \echo "Output"Sleep 1; \Done3, the shell script realizes the automatic input of Telnet, implements with the pipeline, the last while loop is used to give the last command full execution time(Sleep 1; echo "user"; \Sleep 1; echo "Password"; \Sleep

Break is to jump out of the current loop, and continue is to jump out of the loop and start the new loop again[Email protected] test]#CatDemo.SH #/bin/Bash while true; DoRead-P"Please input number:"x yif((x>9)); ThenContinueelif((y>9)); Then BreakElseZ=$ ((x+y))Echo$zfi DoneEcho "Execution completed!"[email protected] test]#SHDemo.SHPlease input number:1 23Please input number:Ten 2 # $x >9, when the back part of the secondary loop is not executing, and the loop starts againPlease input number

Tags: meaning cond centos7 test cat size pre BER syntax errorNote: The comparison string in the shell can only be used = =, Compare numbers using-eq,-ne,-gt,-ge,-lt,-le, or = =, [[Email protected]SH]$CatNumber_compare.SH #!/bin/bash# script Name: Number_compare.SH#用途: Compare two digit sizesEcho "Please input first number :"Read xEcho "You first number x= $x"Read-P"Please input second number:"yEcho "You second number y= $y"if[$x-eq $y]; Then Echo

Today, let's learn about Common Unix shell commands. We all know that Unix shell is not only a user interaction interface, but alsoProgramDesign Language: when the system registers, it will execute a Unix

seconds, in the shell script of the usual term loop.At this point, you press CTRL +z to pause it, and then enter BG to go back into the background.In the case of multitasking, if you want to move the task to the foreground, FG is followed by the task number and the task number can be obtained using the jobs command.9. >>, 2>, 2>> : The above-mentioned directional symbols > and >> denote the meaning of substitution and addition, then there are two sym

What is a shell script Shell scripting (English: Shell script), also known as shell Command Draft, programmatic script, is a computer program and text file, the contents of a series of shell commands, through the

What is a shell script sample Let's look at an example: #!/bin/sh cd ~ mkdir shell_tut cd shell_tut for ((i=0; i Example explanation Line 1th: Specify the script interpreter, here is the interpreter with/bin/sh Line 2nd: Switch to the current user's home directory Line 3rd: Create a directory Shell_tut Line 4th: Switch to the Shell_tut directory Line 5th: Cycle conditions, 10 cycles

files under/var/logPut all the commands in one file and build up the script, here is the simplest command to stack up the script, empty the log script.Cd /var/logCat /dev/null > messagesEcho “Logs cleaned up.”Expand: Three ways to empty logs and file contents[[emailprotected] ~]# echo >test.log [[emailprotected] ~]# >test.log [[emailprotected] ~]# cat /dev/null >test.logScenario: Preserve files and empty content.Two Shell language and category Introd

In Linux or Unix-like systems, each user and process is running in a specific environment. This environment contains variables, settings, aliases, functions, and more. Here is a brief introduction to some of the common commands in the shell environment, including examples of how each command is used, and setting your own environment at the command line to improve efficiency. Find your current

functionality is written in C or C + +, it can take two days, and generally, the script executes fast enough to allow people to ignore its performance problems. Examples of scripting languages are awk, Perl, Python, Ruby, and Shell. When to use the shell Because the shell appears to be a common feature between

Learn Shell to now, always thought that they will not commit a very two problems, the result of this book last time made a very 2, integrity not protect AH!!! I'm under the test file path except wildcard * and? What can be used outside the same thing, the result of the $home under the implementation of RM. All right, the egg hurts for the whole afternoon! Return the wood to any one of the configuration file

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

Do monitoring and backup up to1. What is a shell script?It's a scripting language, not a programming language.You can use some logical judgments, loops, and other syntaxYou can customize the sub-functionis a collection of system commandsShell scripts enable automated operations, greatly increasing our productivity first shell script: mkdir

Learn the first script from the shell, thanks to cloud Li Qiangqiang Teacher's shell programming tutorial To create a shell script file:Touch menu.shTouch index.shTouch welcome.sh To give the script file permission to execute:chmod a+x menu.sh index.sh welcome.sh menu.sh #!/bin/bash#menu.shfunctio

folders, and ended up with a single command line: xcopy /e C:\Windows\assembly\GAC_MSIL G:\GAC_MSIL Then look for the desired assembly in the copied directory. Ha, now we can look at the PS code, it will be a very enjoyable thing.In addition, I found an additional assembly "System.Management.Automation.dll" through the _sfx_manifest_ file and the Reflector Analysis assembly reference, and its EXE note is "Microsoft Command-Line Shell

What is a shell script sampleLet's look at an example:#!/bin/shcd ~mkdir Shell_tutcd shell_tutfor (i=0; iExample explanation Line 1th: Specify the script interpreter, here is the interpreter with/bin/sh Line 2nd: Switch to the current user's home directory Line 3rd: Create a directory Shell_tut Line 4th: Switch to the Shell_tut directory Line 5th: Cycle conditions, 10 cycles Line 6th: Create a test_1 ... 10.txt file Li