bash getopts

The simplest example of--hello world! About input, output, and error outputs Rules for variables in BASH (similarities and differences with C language) Basic Process Control syntax in BASH Use of functions 2.1 Simplest example of--hello world!Almost all of the first examples of programming books to readers are the Hello World program, so let's start with this example today to learn more

Monitor a Linux process with a bash script implementation.Monitor the process using the PS command, and use the Loop plus sleep time for continuous monitoring.Usage:PSMONITOR.SH-P [PID]-D [Interval]-n [Statistics count]Parameters:-p Monitored process ID-D read performance data interval-N statistics, up to the number of times, automatic exit#!/bin/bashinterval=0count=0pid= "While getopts" p:d:n: "Argdo case

Man CD---cannot be queried, so it prompts Bash's built-in commands. Alias BG bind break builtin Caller CD command Compgen complete compopt continue declare dirs disown echo enable eval exec Exit export false FC FG Getopts hash help history jobs kill let local logout mapfile popd printf pushd pwd Read ReadOnly r Eturn Set shift shopt source suspend test times trap True Type typeset ulimit umask unalias unset wait -

Dirsown Removes the specified job from the job list for the process Echo Outputs the specified character to stdout Enable To start or disable built-in shell commands Eval Stitch the specified parameters into a single command, and then execute the command Exec Replace the shell process with the specified command Exit Force the Shell to exit with the specified status code

Understanding of the Bash environment variable Parsing Vulnerability 1. What are environment variables?Both Windows and Linux programs support environment variables. Generally, environment variables are stored at the beginning of the process memory space as value strings. When you execute a program, you can specify the environment variables to pass information to the program to be executed. On a Windows platform dominated by GUI, generally, users seld

Shell commonly known as shell (used to distinguish from the kernel), refers to the "user interface to provide users" command parser (software). It is similar to DOS command and later cmd.exe. It receives the user command and then invokes the appropriate application.At the same time, the shell is a programming language. As a command language, it interactively interprets and executes commands entered by the user, or automatically interprets and executes a predetermined sequence of commands. The sh

Basic syntax for BASH The simplest example of--hello world! About input, output, and error outputs Rules for variables in BASH (similarities and differences with C language) Basic Process Control syntax in BASH Use of functions 2.1 Simplest example of--hello world!Almost all of the first examples of programming books to readers are t

, warnings, and error messages during a script run are identified with different string prefixes, making them easier to identify. Based on the above considerations, the script template is created as follows:#!/bin/Bashscript_name=""script_usage=$ (Cat Eofdescription of script usage. EOF) script_function=$ (Cat Eofdescription of scriptfunction. EOF) script_doc=$ (Cat Eofscript documentation.-H Display this help. EOF) script_examples=$ (Cat Eofscript examples. EOF) state_prefix="==="warning_p

Some basic Bash ProblemsSome basic Bash ProblemsHere we will introduce some issues before and after bash is started, as well as some basic issues that need to be paid attention to when using bash.1. Bash IntroductionBash is a Shell program. It is the default Shell program in

https://www.zhihu.com/question/21418449Mort | Zsh vs. Bash: Incomplete contrast resolution (1) 2014-10-07BdpqlxzWhat's the difference between zsh and bash?A lot of people have written about "why zsh is better than bash", "Why zsh is better than Shell", the tutorial on how to configure zsh or toss various oh-my-zsh themes is a big basket, but rarely see zsh and

Recently there has been a "destructive level" vulnerability--bash software security vulnerabilities. The loophole was discovered by French gnu/linux enthusiasts Stéphane Chazelas. Subsequently, the United States Computer Emergency Response Center (us-cert), Red Hat and a number of companies engaged in safety in Wednesday (Beijing time September 24) issued a warning. Details of this vulnerability are available in the U.S. government's two disclosure of

Shell types:Sh-Bourne shell CSH or tcsh-C shell Korn-Korn shell bash-GNU Bourne-again shell 1. Simplest ColumnExample #! /Bin/bash # This is a very simple example echo Hello World Explanation: In bash, the first line "#! "And later"/bin/bash "indicates that the file is a bash