Shell

I. Shell INTRODUCTIONThe role of the shell is to explain the execution of the user's command, the user enters a command, the shell executes one, which is called Interactive, the shell has a way to execute the command is batch processing, the user

Section one: Breank commands4 loops for, while, until, select, if you want to end the loop early, you can use the break command in the loop. When you perform a break, you jump out of a layer of loops, and if you want to jump out of a multilayer loop,

The usual way to write shell scripts is to use $1,$2 .... This way to receive parameters, however, this method of receiving parameters is not only easy to forget and not easy to understand and maintain. The commands that are commonly used by Linux

Shell ScriptShell script: Always use, but no system to learn, just in the Linux command line mode to knock some simple common instructions, now the system to learn some.First, create a shell script, generally end with. SH (linux suffix is just a

There is a HIVE-E command in hive that can pass parameters, but when the HQL statement is more, the entire shell script will look messy, of course someone might say hive-f can implement a direct call to a file,bingo indeed, but there is a big flaw,

1. Prepare my first shell scriptWhat is a shell script? I would simply say that the shell script is a special program in the Linux system, he works between the operating system kernel and the application, acting as a "command interpreter" role, is

Usage of the Linux Cut commandFont: [Increase decrease] Type: Reprint time: 2013-10-03 I want to commentCut is a selection command that analyzes a piece of data and takes out what we want. In general, the selection of information is usually for

A sample shell script:Gets all file names, paths, and file sizes under the directory (including subdirectories).Code, Shell script: lsdir.sh#!/bin/bash# #site: www.jquerycn.cnfunction ergodic () { forFileinch' LS $1` Do if[-D $1"/"$file] then

Distance from the last write and a period of time, the period has been followed by private food learning, or did not develop a regular record of the habit, today to write the first script.After a few days of accumulation, learning the next shell

The file descriptor is an integer associated with the file input and output. It is used to track files that have already been opened. The most common file descriptors are stdin, stdout, stderr. We can even redirect the contents of a file description

Often read some of the books about Linux still feel unable to fully grasp this knowledge can not be fully mastered as long as you can achieve proficiency in the use of after all, do research and development is able to quickly make products to sell

Sshpass ToolsSshpass can install yum or download source package-P: Specify the password for SSH-O Stricthostkeychecking=no avoid a public key check for the first logon.#!/bin/bash/usr/bin/sshpass-p linux ssh-o stricthostkeychecking=no [email

First, string slices:${var:offset:number} takes a substring of a string;Take the rightmost few characters of the character toe: ${var:-length}Note: There must be a white space character after the colon;Second, To take a substring based on a pattern:1

CentOS Shell Programming 3 "alarm system" 37th sessionThe first half of the classThe second half of the classThe entire project does not have any architecture, is single-machine, without the concept of server-side and clientJust a simple call to

Shell programming1 echo-e recognition \ escape character \a \b \ n \ \x hex \ 08 Binary, etc.#!/bin/bashEcho-e "Hello World"Execute script: Mode 1:chmod 755 hello.sh./hello.shWay 2:bash./hello.sh (this way does not need to give execute permission)1

In the process of writing shell scripts, we often customize some functions and execute the corresponding process according to the function's return value, so how do we get the return value of the function?There are two ways to call a function in the

There are two ways you can execute shell scripts under Linux:1, execute the script with Shell program: According to the type of your shell script, choose shell Program, commonly have sh,bash,tcsh etc. (generally the first line #!/bin/bash indicates

Example: nohup/mnt/nand3/h2000g >/dev/null 2>&1 &for & 1 More accurate should be the file descriptor 1, and 1 is generally representative of Stdout_fileno, in fact, this operation is a dup2 (2) call. He standard output to All_result, and then copy

1, case do with the execution of the option script:#!/bin/bashCase $ inXecho "X is selected";;*)echo "Please use X"EsacSecond, case combined while doing interactive script:#!/bin/bashWhile TrueDoRead-p "Enter Port of Chaoxingdata (d,1):" PortCase

Three days of writing edge test, and finally completed the current longest code script, a total of 253 lines, in 2 machine installation Lamp,lnmp have passed smoothly, the script can be used as a production environment.Where the script needs