bash shell scripting tutorial

two different concepts. For the sake of simplicity, the "shell programming" that appears in this article refers to Shell scripting, not the development of the shell itself (such as Windows Explorer extension development).EnvironmentShell programming is like Java and PHP programming, as long as there is a text editor t

) values in the script after the end of the script, still exist in the current shell, and SH and bash are not, so when doing shell scripting development. If there is a requirement in the script to refer to the contents of other scripts, or to configure the file, use the "." Dot or source to load the script or configura

Tags: ges vim editor nginx root user Form bash script expec Ash rsyncObjectiveLearn about the knowledge reserves required for Shell script programming:Vi/vim Editor Command VIMRC set to be proficientBasic commands, more than 100 skilledBasic and common Network Service commands to be: NFS, rsync, INotify, Lanmp, Sersync, SSH keyI. Shell

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 want to execute the script.To make the script

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 Linux Release 131.2.2 Linux distributions for specific purposes 131.2.3 Linux LiveCD 141.3 Summary 152nd Chapter into the shell2.1 Entering command line 162.1.1 Console Terminal 172.1.2 Graphical Terminal 172.2 Accessing the CLI through the Linux console terminal 182.3 Acce

Tags: bin toward inside File TPS capitalization command line XXX exec xxxxxx15.1 Understanding inputs and outputsNow you know two ways to show script output1) display on the display screen2) redirect the output file to a file15.1.1 Standard File descriptorEach object is treated as a file by the Linux system. This includes the input and the process.Linux uses file descriptors to identify each file object.It is a non-negative integer that uniquely identifies the open file in the session.Each proce

Shell script is similar to batch processing under Windows/dos, that is, the use of various commands pre-placed into a file, convenient one-time execution of a program file, mainly for the convenience of administrator settings or management. The advantage of scripting languages over Perl and Python is that it handles the underlying business because there are a lot of Linux commands to support, such as "Alarm

First, using the For loop structureTarget:This case requires writing a shell script chkhosts.sh that uses a for loop to detect the surviving status of multiple hosts, with the following requirements and instructions:1> Ping Detection of 192.168.4.0/24 network segments2> Ping Detection can refer to the pinghost.sh script of the preceding dayThe 3> script can traverse the ping hosts and feed back the surviving statusAfter the test script is executed, th

as ${name:3:2}: Discard 0-2 of the array variable, only take the 3,4 array variable;Undo Array:Unset Array_NameTo delete an element in an array:Unset Array_name[index]Random variable: Can produce a set of stochastic variables between 0-32767Cases[Email protected] ~]$ echo "$RANDOM"16952[Email protected] ~]$ echo "$RANDOM"6653Five. Bash script programmingThere are three types of shell scripting:Over-program

executionProgramming Model: Process oriented, object orientedprogram = instruction + dataProcess oriented: organization of data as an instruction center. Bash Shell is a process-oriented programmingObject oriented: Data-centric organization of directives.Program Run Model:Compile run:Source--preprocessing----compile----LinkExplanation Run: Bash is the explanatio

Tags: exit USB machine $ Example des user created Linu specifiedChapter 23rd using other shellsThe bash shell is the most widely used shell in the Linux distribution. But it's not the only option, and there are other shells you can choose from.23.1 What is dash shellBaidu Encyclopedia said: Dash Shell is a Unix

As a result of the work, several bash scripts were written in the previous months, primarily for automated testing, packaging, installation packages, and so on. Although compared to C + + programming, to be simple, stupid, but it in the Unix-like system can greatly improve the efficiency of the work. So here's a brief summary of some of the considerations in scripting. 1.

Shell Scripting Learning The shell is the command parser that converts the user-entered instruction into a program that the appropriate machine can run.The shell is a program that acts as an interface between a user and a Linux system, allowing the user to enter commands to be executed to the operating system, which c

Some good habits of shell scripting 1. Naming rules The script name ends with. SH, and names are as famous as possible. Here are a few of the script naming styles that are available for reference. Through the following fresh and refined style, readers can easily understand the role of the script.clearlog.sh clearlog.sh clearsql.sh snmp_install.sh monitor.sh 2.

As we all know, PHP is a very good dynamic web development language (fast, short development cycle ...). ）。 But only a few people realize that PHP can also be a good language for writing shell scripts, and when PHP is the language that writes the shell script, he's not as powerful as Perl or bash, but he has a good advantage. It's especially for people like me wh

Original URL: http://zhu8337797.blog.163.com/blog/static/170617549201122512712136/ Command Options function BASH–X Pin Name Echo Echo Displays each row of the script after the variable is replaced and before the command is executed BASH–V Pin Name With Print the lines in the script as you entered before executing

-22（此处会自动变换为当前日期） # Author: Nanyibo # Email: [emailprotected] # ------------------------------------------ # Copyright: 2017 nanyibo # License: GPLAfter that, automatically opens with Vim, waiting for the user to start writing the script body #!/bin/bash touch /root/bin/$1 chmod +x /root/bin/$1 echo "#!/bin/bash

check if a string begins with the letter "abc"?[[$string = = abc*]][ [$string = = abc*]] and [[$string = = "abc*"]] What's the difference?[[$string = = abc*]]-Check whether the string starts with the letter ABC[[$string = = "abc"]]-check if the string is exactly equal to ABC54) How do I list user names that start with AB or XY?egrep "^ab|^xy"/etc/passwd|cut-d:-f1in bash) $! What does that mean?The PID of the recently executed command in the backgroun

Chapter Three: Basic bash shell commandsThe Bash program uses command-line arguments to modify the type of shell being started Parameters Describe -C string Read the commands from a string and process them -R Launch restrictive

See other people's study summary, feel good turn over (transfer from tryfly)First, Shell Script FoundationThe shell script is a program written using the shell's function, which uses a plain text file, writes some shell syntax and instructions inside, and then uses regular expressions, pipe commands, and redirect functions to achieve what we want to do. Its basic