Shell

This is the first programming job of the operating system principle course, which complements the functionality of the shell.The main implementation of the basic three types of commands Executable program Commands REDIRECT Command

The shell is the interface between the user and the Linux operating system.CCat Zdd Browse the contents of a ZDD fileCat Zdd1 Zdd2 Browsing the contents of multiple filesCat-n ZDD Browse the contents of a file Zdd and display line numbersCD back to

Reference: http://www.51testing.com/html/28/116228-238978.htmlhttp://blog.chinaunix.net/uid-27571599-id-3473078.html         in bash, use background tasks to achieve multi-process tasks. In uncontrolled mode, regardless of the number of tasks, all

1. View the ASCII code table Man 7 ASCII Many people are beginners to the concept of the ASCII code, and sometimes in order to check the ASCII value of a symbol, you may have to rummage to find the current textbook? Linux Manpage

1. In the build environment, the server's password is often modified to ensure security and can be scripted with the shell.Using SSH to directly modify the password of the other server can be implemented with the SSH username @ login IP followed

User management is one of the tasks of Linux system maintenance, in which simple actions such as adding and deleting users are designed.Requirements: Add a lot of users at once. In a text file.Format: In the unit of behavior, each line is a user

> If the file does not exist, as above, if the file exists, clear the file first, then fill in the file with the data>> If the file does not exist, a new file is created and the data is sent to the file, and if the file exists, the data is added

A, delete all data tables for the specified database#!/bin/bash# Delete all tables in MySQL # example: # Usage:./Script user Password dbnane# Usage:./script User Password Dbnane server-ip# Usage:./script user Password Dbnane mysql.nixcraft.inch# ----

usage rights: All usersCommand: CHSHUsage:shell>> CHSHDescription: Changing the user shell settingsExample:Shell>> Chshchanging fihanging shell for User1Password: [del]New Shell [/bin/tcsh]: # # # [is the currently used shell][Del]Shell>> Chsh-l # #

Problem descriptionFor Linux systems, many times are used for servers and the like, this time is not open desktop system, so that the command line operation, can effectively save the use of system RAM, so that as many resources as possible for the

Shell string manipulationThe bash shell provides several commands for string processing: awk command Expr command String length ${#..} Length of expr Length of awk (s)Instance:string= "Hello World"$ {#string}Expr

Today, big data boss gave me a task-grabbing stock history data. As a wget, I looked for it on the Internet and found that it was really a very powerful Linux download tool. I have been deeply shocked. The following is a description of some of today'

1. String judgmentSTR1 = str2 When two strings have the same content, length is trueStr1! = str2 True when string str1 and str2 are not equal-N str1 True when the length of the string is greater than 0 (string non-null)-Z str1 True when the string

#!/bin/sh#auto Change IP netmask Gateway scripts#wugk 2012-12-17Cat ++++++++ automatically modifies IP and host name information +++++++++Ethconf=/etc/sysconfig/network-scripts/ifcfg-eth0Hosts=/etc/hostsNetwork=/etc/sysconfig/networkdir=/data/backup/

1. FindFind Pathname-options [-print-exec-ok]Let's take a look at the parameters of the command:Pathname the directory path found by the Find command. For example, use. To represent the current directory, and/to represent the system root

Background:The items that are built daily are placed in different folders by date. As today's construction is put into 2015-06-01, tomorrow's will be put into 2015-06-02, and so on. Long time, need a script to delete the folder N days ago. (In this

Recently help students write a simple script = = (do not spray me ~), the situation frequency, the background operation and the concept of CTRL + Z did not understand clearly made a big joke, the script and the resolution process:#!/bin/bash

playing Linux does not know the shell, that is, do not understand Linux. This statement is enough to witness the shell's position in Linux operations. Always want to write down the shell, but always do not know how to write, not because the shell is

Problem:The directory structure is as follows:test/2001.01.01/2001.02.02/2001.03.02/2001.01.03/2001.02.04/2001.03.05/2001.01.04/2001.02.05/2001.03.07/2001.01.06/2001.02.06/2001.03.08/2001.01.12/2001.02.23/2001.03.09/2001.01.13/2001.02.26/2001.03.22/2

Shell script programming (strict terminal format control, beautiful output font color), shell script Programming #! /Bin/bash # font output color and terminal format control # font color 30-37echo-e "\ 033 [30 m black character \ 033 [0 m" echo-e "\