bash shopt

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

Shell:An interface program that completes interactive operations between the user and the operating system, providing users with simplified operations; In the 70 's mid-century in Bell Labs, Bourne bit UNIX developed a shell program Bourne Shell, referred to as SH;Bill Joy: Rewrite c Shell in C according to SH, abbreviated as CSH; lie on the bed for its derivative version;David Korn: A collection of the advantages of Cshhesh development of the Korn Shell, referred to as Ksh;Gnu:gnu Organization

Article Title: Custom bash. 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. Finally, we installed the Solaris 10 u8 on the Sun Fire V890 and got started with minicomputers. Since Linux has been used for a long time, we like bash (bourne again shell) very much, but it is

Bash Shell and bashshellI,Terminal Printing [Root @ cai ~] # Echo welcome to bash! Welcome to bash! [Cairui @ cai ~] $ Echo 'Welcome to bash! ' Welcome to bash! [Cairui @ cai ~] $ Echo "welcome to bash \! " Welcome to

. Copy Code code as follows: #!/bin/bash Declare-i sum=0 For I in {1..100}; Todo If [$[$I%3]-eq 0]; Then Let sum+= $I Fi Done echo "The sum is: $sum" 2. Calculate all odd numbers and all even numbers within 100 Copy Code code as follows: #!/bin/bash # echo "Exercise" Declare-i sum1=0 Declare-i sum2=0 For I in {1..100}; Todo If [$[$I%2]-eq 0]; T

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

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

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 of a script or program is generally done in tw

In Linux, how many types of executable files are available? How does one execute a program in the bash environment? Next we will analyze them one by one.1. Types of executable files in Linux: 1.1 binary executable files This type of file is the most common, such as/bin/ls,/sbin/ifconfig,/bin/cat, and so on. [Root @ notebook135 ~] # File/bin/ls/bin/cat/sbin/ifconfig /Bin/ls: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), dynamically linked

Shell script Programmingcompiler-------Interpreter static language: compiled language, strongly typed (variable), converted into executable format beforehand. c/c++/java/c# Dynamic Language: Interpreted language, weak type. The side explanation changes the execution. Php,shell,python,perl oriented process: shell,c; object-oriented: java,python,perl,c++ variable assignment: var_name = value;bash Variable type: Environment variable: The scope

Label: Bash script Shell is a scripting language for control systems. Bash is one of the shell interpreter and the most popular one in Linux. However, there are many shell interpreters, and each type has its own characteristics, not exactly the same .., Common shell: Sh, CSH, tcsh, Bash, KSh, Dash, zsh Common ba