Shell

First, expect explanation Expect allows us to automatically log on to remote machines, and can implement automatic remote execution of commands. Of course, if you use key authentication without a password, you can also implement automatic

Shell commands are usually divided into two categories:Built-in commands (man Builtins)External commandThe difference between the two is analyzed below.Built-in commands:Internal commands are built into the shell. The internal command executes very

Transferred from: http://www.cnblogs.com/include/archive/2011/12/09/2307905.htmlReference:http://www.51testing.com/?uid-7701-action-viewspace-itemid-13731http://blog.csdn.net/sunboy_2050/article/details/6836382Shell BracketsWhen learning the shell

Based on some articles on the reference Web, a system-initialized shell script is summarized.#!/bin/bashcat /dev/nullyum-y install ntpdate &>/dev/ Nullntpdate 0.centos.pool.ntp.org &>/dev/nullhwclock-wformat###########################################

The relationship between the computer and the kernel, the shell: first, the management of the entire computer hardware is actually the operating system kernel (kernel), the kernel is required to protect, so our average user can only through the

ls: View file name and directory, usage: $ ls [option]1. $ lsEnter the LS command directly, listing all files and directories in the current directory, without displaying details such as type, size, date permissions, and so on.2. $ ls-lThe-l option

Purpose: Self-collation, self-review, self-reflection!Content: Dry Goods! Dry!! Dry!!!Attach: The shortcomings of the hope that you correct, can give like me rookie a little inspiration is the best. Just the inspiration ...Thank you: Thank the old

7. If you judge some special usageIf [-Z $a] This indicates what happens when the value of variable A is emptyIf Grep-q ' 123 ' 1.txt; Then what happens if the 1.txt contains a ' 123 ' rowif [!-e file]; Then what happens when the file doesn't

Hardware Chapter CPU-related Lscpu #查看的是cpu的统计信息. Cat/proc/cpuinfo #查看CPU信息详细信息, such as the model of each CPU, frequency, etc. Memory-related Free-m #概要查看内存情况 The unit here is

Knowledge Point Grooming: Click the link to enter1. Shell Introduction and variables, scripting related concepts2. Bash Programming: Condition testing3. Bash Programming: arithmetic operations4. Bash Programming: If statements5. Bash Programming:

String test:= =: Determine string equality！ =: Judge strings are not equal-N: Tests whether the specified string is empty-S: Tests whether the specified string is not emptyLoop statement:for variable in list; DoLoop bodyDoneExample:For I in 1 2 3 4 5

This paper aims to review the basic concepts of shell, programming model, variable type, script specification, language structure, script execution modeLinux hierarchy and Shell basic concepts The Linux hierarchy is roughly divided into

-------------------------------------------------------------------------------------------------The types of variables in the shell are all strings by default, so:#!/bin/Bashaa=1bb=2cc= $aa +$bbEcho $cc 1+2Number of ways to calculate:Declare

Linux production server shell script sharing2012-6-6 86 Market Network LinuxAs a Linux/unix system administrator, I often meet people asking this question: what can the shell do? PHP is so powerful, why not use PHP to get the job done? In fact,

Tag: null 1.read read mode: [[Email protected] scripts]# vim read_1.sh   1 #!/bin/bash   2 # Filename: read_1.sh  3 # Describe: Integer  arithmetic  4 # author: lijun  5 # date: 2015-08-24   6 # Version: 1.0.1  7    8 read -p  "please

1. Script instanceSave the following script as getftp.sh# !/bin/bash datesign= ' date-d -95day +%y%m%d ' ftp -NV 12.2.2.28 ! Ftprunuser User01 User01 Prompt bin CD TXT LCD /app/info/getftpmget ${datesign}*. Txtbye! FtprunScript

Linux bash Shell's declare declare or typeset built-in commands (which are exactly the same) can be used to constrain the properties of a variable. This is a way to use a less restrictive definition type in some programming languages. Command

Basic Regular expression (supports shell tools such as Grep,sed,awk)* 0 or more of the ordinary characters in front of the * character. Match any character^ matches the beginning of the line, or the following character is non$ Match Line End[] Match

function allows us to divide a complex function into several modules, which makes the program structure clearer and the code reuse more efficient. Like other programming languages, the Shell supports functions as well. The Shell function must be

Similar to other programming languages, the shell supports A for loop.The general format for A for loop is:For variable in list Docommand1command2...commandndoneA list is a sequence of values (numbers, strings, and so on), each separated by a space.