bash shopt

BASH command and usage summary, bash usage Summary I need to write a Linux script in my recent work and use a lot of BASH commands. To avoid forgetting it later, I will write them down here one by one. It may be messy. Just take a look. If something is wrong, you are welcome to correct it. 1, export VAR =... This command runs in Shell to make the script that runs

Bash internal variable learning and Bash variable learning $ SECONDS variable --------- number of SECONDS after the script has been run. Script instance: 1 #!/bin/bash - 2 #=========================================================================================== 3 # 4 # 5 # FILE:seconds.sh 6 #

Linux new user with ssh remote login display-bash-4.1 $, ssh-bash-4.1 There are many methods on Baidu, most of which are in the form of adding PS1 code in. bash_profile, and then logging on to the account again... This method is difficult to achieve the desired results. The root cause of this problem is the lack of Shell environment! [Root @ localhost ~] Su-papi1Last login: Wed Jan 24 04:11:41 EST 2018

Bash script skills-trap Command, bash script-trap Share a shell script technique. When you write a shell script, you generally only ensure that the function is available, but the program is not very robust and not robust enough. Most of them are script processing. The built-in trap command can handle unexpected system signals, for example: Trap "rm-f/var/lock/subsys/my_program_lock_file; Exit 0 "1 2 9 15

There are multiple types of Shell in Linux, the most common of which are Bourne shell (SH), c shell (CSH), and Korn shell (Ksh ). Each of the three shells has its own advantages and disadvantages. The Bourne shell is the original shell used by UNIX and can be used on every UNIX. Bourne shell is excellent in shell programming, but it is inferior to several other shells in dealing with user interactions. The default shell in Linux is the Bourne again shell, which is an extension of the Bourne shel

Linux Bash Shell learning notes, bash learning notes Parameter extension: 1. The parameter referenced by the name is called a variable.2. Parameters referenced by numbers are called positional parameters.3. Parameters referenced by a specific symbol have special meanings and purposes, and are referred to as Bash's special internal variable reference. Basic Parameter extension:Character $ will guide paramete

Bash basics man manual and bash basics manBash basics man Manual Penetration tests based on Android devices are implemented through various terminals. Therefore, it is particularly important to master Shell-related operations. Bash is a Unix Shell program written for GNU. This document selects the Kali Linux penetration test tutorial Based on Android devices. It

pre-Class review : To find the sum of divisible by 3 divisible by 200# !/bin/bash -Isum= 0 for with {1..200};d o if [$[$i%3]-eq 0]; then let Su M+="Thesum is: $sum"Bash's knowledge points :Conditional testing: Making a logical operation on a condition　　　　　　　　　　　　with : Condition 1 Condition 2　　　　　　　　　　　　or : Condition 1 | | condition 2　　　　　　　　　　　non- :! Conditions　　　　　　example :#userName =root#id $userName echo "userName exist"If the former fails,

Description : This is a relatively simple bash script editor, but has been tested. The reason for writing this blog is to practice the loop control language, functions, positional parameters, local variables, and function parameter calls, as well as calls between functions, as well as parameters for obtaining user options and options.Note: The script options and the script options parameter get method use getopt and make further judgments, consult the

Bash: insufficient permissions and insufficient bash Permissions This problem occurs today when a file is opened on a terminal under ubuntu. Suddenly, the file is read-only, so you need to open its user permissions. The specific implementation is as follows: chmod 777/home/example/filename. In this way, all permissions of this file are opened and can be accessed as much as possible. The details of chmod are

Linux bash integrated instance bash Script Editor, linuxbash Note: This is a simple bash Script Editor, but it has been tested. The reason for writing this blog is to exercise loop control language, functions, location parameters, local variables, function parameter calls, and inter-function calls, there is also the parameters for Obtaining user options and optio

The operating environment of the Bash Shell:Configuration values are divided into the overall system configuration values and preferences of each person, only some files placed in different places! Path and command search orderWhen a command (such as LS) is released, which LS is it running? Run the command in a relative/absolute path, such as "/bin/ls" or "./ls"; Run by alias to find the command; Run by

 Today burst a bash rce loophole, powerful. Look at the analysis of foreigners, feel the need to write their own understanding of this loophole. First, the problem results from a command env. Prototype: env [OPTION] ... [Name=value] ... [COMMAND [ARGS] ...] That's what man says: Display, set, or remove environment variables,run a command in a modified environment. My understanding is that using the key=value of the ENV command will first change th

In fact, after editing the bash script, you can use the Bash-n-X two options for script checking, not necessarily to run the program when the need to modify the script.Bash not only has the meaning of running scripts.No news is good news.I'm going to modify the original script a little bit.The-n effect I can not demonstrate now, before it is possible to directly point out the syntax errorThis is the effect

In Windows 3.02 64-bit system, when cygwin is used to run the liunux program, the following error occurs: Bash-$: The reason is: In the 64-bit operating system, the 32 program and the 64-bit program read the location registry key, in the 64-bit Registry Editor, HKEY_LOCAL_MACHINE \ SOFTWARE corresponds to the registry key of the 64-bit program, and the 32-bit registry key is mapped to HKEY_LOCAL_MACHINE \ SOFTWARE \ wow6432node. If both versions are r

Bash array, bashBash only supports one-dimensional arrays. And the array subscript starts from 0.Assign values to Arrays:Array = (1 4 7 2 5 8) # use space as the delimiter and () as the arrayStr = "this is test string"Str_arr = ($ str); # separated by spaces by defaultArray traversal:For val in str_arr [*]; do echo $ val; doneFor file in 'LS'; do echo $ file; doneNumber of array elements: $ {# array}For example, each character in a string is split int

$filename/etc/sysconfig/network-scripts[[email protected] Network-scripts] #将第一次出现的小写s替换成大写的S [[email protected] network-scripts]# echo ${filename/s/s}/etc/sysconfig/ Network-scripts[[email protected] network-scripts] #将所有的小写s替换成大写的S [[email protected] network-scripts]# echo ${ Filename//s/s}/etc/sysconfig/network-scripts[[email protected] network-scripts]# Summary:/match/ Value: Replace the first occurrence of match with Value//match/value: Replaces all match with value Operators for