learning bash shell

globstar description is mentioned only twice, and the same thing is said, as follows: Pathname Expansion......* Matches any string, including the null string. When the globstar shell option is enabled, and * is used in a pathname expansion context, two adjacent *s used as a single pattern will match all files and zero or more directories and subdirectories. If followed by a /, two adjacent *s will match only

1. What is Shellscriptshellscript is to use the shell's function to write a "program", the program is to use a plain text file, some shell syntax and commands (including external commands) written inside, with regular expressions, Pipeline command and data flow redirection, conditional judgment statements and other functions, in order to achieve our desired processing purposes. 2. Script or program source files are plain text files. 3. The execution o

shell is the shell is a command interpreter. More than just the insulating layer between the operating system kernel and the user, it ' s also a fairly powerful programm ing language. There are two kinds of shell and command line shell of GUI. The shell manages your interac

This article mainly introduces the output of the shell (bash) "time" command, and provides detailed sample code, I believe that it has some reference value for everyone's understanding and learning. if you need it, let's take a look at it. Preface I believe everyone knows that time in bash is a very useful command. it

5.2 Bash Variables The following variables are set or used in Bash. Other shells generally do not process these variables. Some variables used by Bash are also described in other chapters: for example, for variables used by tools for controlling jobs, see 'job control variable '. BASH Execute the full path name of the

beginning of each line. In Vim, if your tab is 4 spaces, you can use this to replace the command: Copy Code code as follows: : s/^/\t/ Ix. command-line parameters Here is an example that completes the use of the above usage function. I got this code from http://kirk.webfinish.com/2009/10/bash-shell-script-to-use-getopts-with-gnu-style-long-positional-parameters/. Copy Code

Bash-shell Startup File Linux uses environment variables to identify itself in programs and scripts. This provides a simple way for your program to obtain system information. The question is how to set these variables. When you log on to Linux and start a bash shell, bash se

Bash shell Command (1), bashshell command Address:Http://www.cnblogs.com/archimedes/p/bash-shell1.html, Reprinted, please specify the source address.Ls command Ls is used to list the contents of a directory. It is one of the most commonly used commands. The format of ls is as follows: Ls [Option] [directory name or file name] Main parameters: . Options Main Param

Iii. Command HistoryBash has absorbed a lot of essence from the Korn shell and the C shell, one of which formally holds the feature of a cached copy of the executed command, which we call the "command history" feature.Why should we use the command history feature?After each user login succeeds, especially after login with file interface such as bash, all operatio

Deletes the specified variable. The variables are not actually deleted, but are not exported to the execution environment of the subsequent directives. -p lists all the environment variables that the shell assigns to the program. You can view all current environment variables by typing export only. If you want to add some new paths (such as/bin/bash) to an environment variable (such as path), you

shells for bash on the current system and the default shell is /sbin/nologin's Users and statistics The total number of users under various types of shell, showing the results in the form of: Bash,3user,they Are:root,redhat,gentoo Nologn,2user,they are:bin,ftp Copy Code code as follows: #!/bin/

What is a shell?The shell typically represents two levels of meaning, one is the command interpreter, such as bash, and the other is the shell script. In this section we stand on the command interpreter's point of view to illustrate the shellCommand interpreter shell develop

pattern is followed by a /, only directories and subdirectories match. A shell script for testing and learning globstar is written as follows: #! /Bin/bashfunction show(){ for i in ** do echo $i done} cd /root/jay/echo "------------------------"echo "disable globstar option:"# globstar is disabled by defaultshopt -u globstarshowecho "-----------------------

outputOutput1Output2h.sh ContentFigure 9[Email protected] ~]#./h.sh[[email protected] ~]# cat outputOutput1Output2[email protected] ~]# cat Output_errTest errorTest Error2Input redirectEXEC 0h1.sh ContentSee Figure 10[Email protected] ~]# chmod u+x h1.sh[Email protected] ~]#./h1.shLine #1: Test errorLine #2: Test Error2PipelineRedirect the output of one command to the input of another commandCommand1|command22 commands are performed at the same time instead of executing one before continuing th

What is Bash shell script programming?A: There are multiple shells in Linux, and the default shell for CentOS and Redhat is the bash shell. As for shell scripts, this is a bit like (. bat file) for batch files inside the Windows o

Always thought that in the shell script # is to represent the annotation function, also at the beginning of the script #!/bin/sh also just tell the user this is a shell script, and recently checked the next, only to find that this is not the meaning, share the following article.Transferred from: http://www.cnblogs.com/EasonJim/p/6850319.htmlFirst, meaning#!/bin/sh means that this script uses /bin/sh to inte

(such as/bin/bash) to an environment variable (such as path), you can use the following command formatExport Path=/bin/bash: $PATH2.bash commandLike the sh,bash,./command is used to execute shell scripts, the use cases are as follows:[[email protected] bin] #

Tags: cin technology share Microsoft-O-Clear CTO SOF Ant 1.5Often heard: Shell programming, bash programming, and bash shell programming, what is the shell, and what is bash, what are the links between the two ... bourne

Objectivea problem has been encountered at work today, if you copy the files from directory A to directory B (without the file in directory B) and keep the files in directory A. The focus of the project is as follows: You need to keep the structure of the file in directory A in directory B. Suppose a directory file A/test/1.txt, transfer to directory B should be b/test/1.txt. You also need to consider whether there is a test directory in directory B, and the multi-level directory should conside

BASH shell set font and background color Echo-e "\e[31mtest\e[41m" \e[30m change the display color of a character to black \e[31m change the display color of a character to red \e[32m change the display color of a character to green \e[33m change the display color of the character to light red \e[34m change the display color of a character to blue \e[35m change the display color of a character to purple \