linux shell scripting cookbook

From the 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. The user can either enter command execution or use shell scripting to do more c

Linux Shell script series (3): variables and Environment Variables This article mainly introduces the Linux Shell script series (3): variables and environment variables. This article describes common variables, get the length of strings, environment variables, and so on, for more information, see I. Game variables and

How can shell scripting be used better? Especially in UNIX and Linux operating systems. Next, let's take a look at how to use shell script programming. Like other UNIX operating systems and Linux systems, IBM? AIX? The operating system provides several powerful tools to help

Tags: technology sharing run Program Shel image language one etc programming LinuShell Concept :The shell is a command-line interpreter that provides users with an interface system-level program that sends a request to the Linux kernel to run the program, and the user can start with the shell, suspend, stop, or even write some programs.The

used as file variables. Bash is the Shell of the Linux operating system, so the file of the system is necessarily an important object that bash needs to manipulate, such as if [-x/root] can be used to determine whether the/root directory can be entered by the current user. The following table lists the operators used to determine file properties in BASH: Operator Meaning (returns TRUE if

The shell script is a script that we write different types of commands that can be executed in this file. We can also A typing command is performed manually. If we're going to use a shell script, we have to write these commands in a text file at the beginning, and then You can run these commands over and over again.Suppose you already know shell

Guide At the beginning of learning Inux shell scripting, for its arithmetic and logical operations. It is estimated that many friends feel more difficult to accept. When using the special variable logical operator "[]", you must ensure that there is a space between the operator and the arithmetic. Arithmetic can only use: let,expr and other commands to complete. Today's statement of the double-brace "(

Tags: + + variable one block arch friend many expressionsThe Linux Shell "(())" Double parenthesis operator uses theAt the beginning of learning Inux shell scripting, for its arithmetic and logical operations. It is estimated that many friends feel more difficult to accept. When using the special variable logical opera

information in a text file. Typically, awk handles units as an act of a file. awk processes the text every single line that receives the file, and then executes the appropriate command. Invoke awk There are three ways of calling Awk 1. Command line mode Copy Code code as follows: awk [f field-separator] ' commands ' input-file (s) Where commands is the true awk command, [-f field separator] is optional. Input-file (s) is the file to be processed.In awk, each item

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

,kubuntu, etc.), and on the gnu/linux system itwill automatically, intelligently search, install, upgrade and resolve dependencies for the package.[Email protected]:~# apt-get Install MPlayerTar commandThe "tar" command is a tape archive (Tape Archive), which is useful for archiving and extracting files that are created.[Email protected]:~# tar-zxvf abc.tar.gz (remember ' Z ' stands for. tar.gz)[Email protected]:~# tar-jxvf abc.tar.bz2 (Remember ' j '

from Windows to the Linux of the Shell scripting Coding and formatting issuesShell script encoding and formatting issues from Windows to Linux1, abnormal problem: set Ff=unix Startup script in the start times error, such as the execution of SH start.sh, when the command is not found and so on, Because the script that we write or modify in Windows is

direct input MySQL password on the command line above), then your host can be nerve-racking! Is it better to record more or less commands? This part is a matter of opinion, there is no definite answer.Command and file completion features: ([tab] key Benefits)[Tab] is followed by the first word of a sequence of commands, then the command is complete;When [Tab] is next to the second word of a string of commands, it is "file completion"!Command alias Configuration feature: (alias)You can enter ali

multi-tasking purpose!Programmatic scripting: (shell scripts)In the DOS era, remember the so-called "batch file" that writes a bunch of commands together? The shell scripts under Linux is a more powerful feature that allows you to write a sequential command that is often required by your management system as a file th

conditional selection are generally competent for simple shell scripts that do not contain variables. However, when you perform some decision-making 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 option

Tags: Linux timed release cache shell script implementationUsers of the Linux server should know that when Linux is in use, the available memory will slowly become smaller over time, and it may eventually reach 80%-90%, which requires us to intervene manually to release the Soul village.This article will use the