bash getopts

Recommendation: 10 Technical Masterpiece: "High-performance Linux server construction combat Ⅱ" full-network distribution, with probation chapters and the book instance source download!A bash security vulnerability has just erupted today, and Bash has a security vulnerability that directly affects UNIX-based systems such as Linux, OS X, and so on. The vulnerability could cause a remote attacker to execute a

The basic syntax for BASH• The simplest example--hello world www.111cn.net! • about input, output, and error output The bash of variables in the Chinese language (and the similarities and differences between C languages) The basic Process Control syntax in bash • Use of functions 2.1 Simplest example--hello world!The first example of almost all the programmi

Bash is arguably the most widely used shell in the *nix world, and one of its characteristics is the historical command (history) mechanism. This mechanism is mainly used for the convenience of the user-less knocking on the keyboard, improve work efficiency. However, it is widely discussed that bash_history can be used as a logging mechanism to monitor user activity. This article will discuss the above questions and explain why the logging mechanism i

RedHat 5.x, 6.X Bash vulnerability RPM patch package download RedHat 5.x, 6.X Bash vulnerability RPM patch package download and tutorial. First, check the BASH version number of the server: Bash-version Install the three files in the bash-4.1.2-15.el6_5.2.x86_64 folder if th

Bash uses special environment variables for code injection attacks Bash or Bourne again shell is a UNIX-like shell script, which may be the most common installation component in any Linux system. Since its birth in 1980, bash has evolved from a simple terminal-based command interpreter to many other exotic uses. In Linux, environment variables affect system softw

Several bash Initialization Files-general Linux technology-Linux programming and kernel information. The following is a detailed description. (1)/etc/profile Global (public) configuration. No matter which user, the file is read during logon. (2)/ect/bashrc Ubuntu does not have this file, which corresponds to/ect/bash. bashrc It is also global (public) This file is read in any way during

On September 6, September 25, 2014, a severe bash vulnerability was detected on the Internet!I was confused and did not know what happened, so I asked "du Niang" to find out what happened. This vulnerability is even better than OpenSSL's painstaking efforts!At that time, the solution was to upgrade the bash-4.1.2-15.el6_5.1.x86_64 to solve the problem. I tested it on the Virtual Machine and compared it with

Debian7 offline upgrade bash vulnerability-refix method, debian7bash ### The old saying yesterday is that we need to release a new patch. Today we are all released. The basic operation is the test results are different. Continue to fix the bash vulnerability in the Debian7 wheezy version, as shown below: 1. Test whether upgrade is required # Env x = '() {:;}; echo vulnerable '

Article title: shell introduction-bash programming parameter description. Linux is a technology channel of the IT lab in China. Includes basic categories such as desktop applications, Linux system management, kernel research, embedded systems, and open source. When you log on to the system, you have started to use bash, but we can also start bash on the command l

Bash contains some powerful tools and conveniences. If you are a frequent user of the command line, these can reduce the amount of input you have. This article provides 10 of the most useful tools: 1. Easy to invoke previous commandsBash retains the commands you execute in a history buffer and allows you to loop through the previous commands with the cursor keys up and down to call them again. Even for a faster recall, you can "quickly find" a previou

Linux Bash Security Vulnerability repair Recently, a very serious security vulnerability was detected in the built-in Bash of Linux. Hackers can exploit this Bash vulnerability to completely control the target system and initiate attacks. To avoid Linux Server impact, we recommend that users with Linux servers fix the vulnerability as soon as possible. [Software

The most common activation modes of bash are interactive and non-interactive:1. Interactive ActivationThe standard input and output are connected to the terminal. There are three types: Login, non-login, POSIXAnd restricted shell.Check whether a shell is interactive. You can check the $ PS1 environment variable.(1) When Bash is activated as the login shell, it reads and runs the following files in sequence:

The shell itself is an application, an interface program that completes interactive operations between the user and the operating system, providing simplified operations to the user.Bourne Again shell, or bash, is the default shell program in a Linux system.features of bash: The alias of a command (custom command)Alias (inline command), defining or displaying aliases using \command, the original command wil

Bash An arbitrary code run vulnerability exists in the environment variable: "A CGI request can cause remote code to run, causing the server to be compromised." Serious harm . and the official release patch was also bypassed " ,"Vulnerability Impact":1) Bash affected version number: 3.0 ~ 4.3, the bash version number less than 3.0 may also be affected.2) Intrus

: #!/bin/sh #对变量赋值: Note that there should be no space on both sides of the equal sign A= "Hello World" # now print the contents of variable a: echo "A is:" Echo $a Sometimes variable names can easily be confused with other words, such as: num=2 echo "This is the $NUMND" This does not print out "This is the 2nd" and only prints "This is the" because the shell searches for the value of the variable numnd, but the variable has no value. You can use curly braces to tell the shell what we

Bash job control Job control is a powerful function provided by bash Shell. It allows you to choose whether to run a program, that is, a job, on the foreground or in the background.1. Enable bash job control. # Set-o monitorOr# Set-m2. Jobs displayed in the background # Jobs[1]-running gedit [2] + running sleep 1000 + Indicates the job that is last run in the bac

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

Detailed Anatomy of bash script programmingbackground: bash scripting is a crucial part of Linux learning, and it may be easy to complete a script, but it's not easy to make your own script write. Bash is almost always available for all Linux distributions, so let's take a bash script as an example to discuss how

Linux file Max connections --- bash: ulimit: openfiles: cannotmodifylimit: Operationnotpermitted problem description: logon system error,-bash: ulimit: openfiles: cannotmodifylimit: Operationnotperm... Linux file Max connections --- bash: ulimit: open files: cannot modify limit: Operation not permitted problem description: logon system error,-

Basis Learn the basics of Bash. Specifically, enter man bash and browse at least the full text; it's simple and not long. Other shells may work well, but Bash is powerful and available in almost all cases (learning Zsh,fish or other shells is handy on your own computer, but in many cases it restricts you, such as when you need to work on a server )。 Learn