Shell

First, what is the shell? The shell is a scripting language aming_linux blog.lishiming.net You can use logical judgments, loops, and other syntax Functions can be custom-defined The shell is a collection of system commands Shell scripts

How awk WorksThe first step: Execute Begin{action ...} Statements in a statement blockStep two: Read a line from the file or standard input (stdin), then execute the pattern{action ...} Statement block, which scans the file row by line, repeating

Requirements: accurately monitor CPU with top commandPreparation knowledge: Top use, basic awk, DC (default bash shell does not support decimal operations)The script is as follows[[email protected] scripts]# cat cpu.sh #!/bin/bash -# top -n 参数指定运行次数，

First, condition judgmentClassification:Condition test TypeNumerical testString testFile test1. Conditional test ExpressionsFormat:[Expression][[Expression]]Test expression2. Numerical test Parameters Description -eq

Basic features of Bash (3)1, provides the programming environmentprogram = instruction + dataProgram Programming StyleProgram: command-centric, data-serving instructionObject type: Data-centric, instruction serves dataShell program: Provides

Shell Special variables: Shell $0, $#, $*, [email protected], $?, $$ and command line arguments special variable list variable meaning $0the file name of the current script $n the arguments passed to the script or function. N is a number that

While loopBasic syntax:While do DoneThe while loop is more used to read the contents of the standard input to implement loopsExample 1: Printing numbers sequentially#!/bin/bash#while test#by Sunnyi=10while ((i　　　　Shell Script VI: Loop while

#!/bin/bash#Date: Writing Time 2016-11-22 15:04:12 # #date "+%y-%m-%d%h:%m:%s"#Author: author#Mail: Email [email protected]#Function: Script Introduction#Version: version V1.1#Update: Script Modification Update time6.1.1 version and Operating

Ctrl + d        删除一个字符，相当于通常的Delete键（命令行若无所有字符，则相当于exit；处理多行标准输入时也表示eof）Ctrl + h        退格删除一个字符，相当于通常的Backspace键Ctrl + u        删除光标之前到行首的字符Ctrl + k        删除光标之前到行尾的字符Ctrl + c        取消当前行输入的命令，相当于Ctrl + BreakCtrl + a        光标移动到行首（Ahead of line），

I. Shell environment and features 1.1 what is a shellInterpreter: Responsible for translating and communicating user/program instructions to the kernelInterpreter carShell carBash BMW, Mercedes, Ferrari1.1.1/etc/shellsThe content inside the file is

number of logged-in users: who | Wc-l See which users are logged on to the system : who Create a new file /bin/ct11, enter a command in the file,chmod Set the Execute permission for the file # cat >/bin/ct11W.H.O. | Wc-lPress Ctrl+d# Cd/

In some complex Linux maintenance work, a lot of repetitive input and operation is not only time-consuming and error-prone, but writing a proper shell script, can be batch processing, automating a series of maintenance tasks, greatly reducing the

Sometimes in the Linux operating system need to calculate the length of a string, through the query data to collate the current shell to get the length of the string of several methods, here to share, the method is as follows:Method 1: Use the wc-l

Like many of my classmates, I was confused shell programming before I learned shell programming, but I didn't know what it could do, but I felt I could use a different way to manage the system. Now I slowly understand the importance of the shell for

FS Shell Cat Chgrp chmod Chown Copyfromlocal Copytolocal Cp Du Dus Expunge Get Getmerge Ls Lsr Mkdir Movefromlocal Mv Put Rm

Background: I have summed up some knowledge points about my common shell scripting style. Also as part of the handover work document. Part of the content is written separately#!/bin/sh# Shell Script Advanced Tutorial # 1. Common knowledge Points:

Three ways to start bash shell1, log in as the default login shell2. Interactive shell as a non-login shell3. As a non-interactive shell for running scriptsFirst, login shellWhen you log in to a Linux system, the bash shell starts as a login shell,

Jenkins Automation Deployment Goal: Jenkins on point build (also automatically check code changes automatically build) "Project deployment complete." First, install the jenkins1. Download JenkinsHere I choose is the war package installs Jenkins,

#!/bin/bash ## description:  the script function, cycle in weeks; Friday full backup, Saturday No backup, Sunday to Thursday differential backup;#                due to work needs, do not implement compression packaging method, using CP full backup,

Functions in the shellThe function is to organize a piece of code into a small unit, and give the small unit a name, when the code is used to call the name of the small unit directly. Format: function F_name () {Command}The function has to be on the