Linux

Exit 1 to end execution in the middle of the scriptCases:[email protected] script]# cat usertest.sh#!/bin/bash#Testuser=hbaseif! grep "^ $TESTUSER"/etc/passwd &>/dev/null; Thenecho "Not find User: $TESTUSER"Exit 1FiUseruid= ' grep ' ^ $TESTUSER

The history of 1.Linux: Linux was developed by a college student named Linus Torvalds of the University of Helsinki in 1991, and Linux is the name of the operating system kernel.2. Embedded System: The so-called embedded system refers to a

Terminal classification:Physical Terminal: Keyboard, mouse, monitor and other physical devices connectedSerial terminal: Remote connection via telephone linePseudo-terminal: Xshell a remote terminal that can manipulate a computer via software

1. Shortcut keys under the command lineComrades who often work under the command line may use up to two keys, which are used to recallHistorical command; Use the left and right arrows to move the cursor backwards or forwards to modify the last used

Log_format is the format used when storing logs and can be set in the HTTP field of/usr/local/nginx/conf/nginx.confThe following is a typical Log_format settingLog_format main "" $http _user_agent "" $http

For Tomcat Log management, after the deployment of Tomcat, running long, catalina.out files will become larger, the stability of the system has a certain impact.1 You can modify the Conf/logging.properties log profile to block out this part of the

Text processor word processing software wordVI (Visual Interface) vim (vi improved)The Emacs mini-machine can be used to open Web pages with powerful featuresVim is mainly in LinuxModal editorInput mode (insert mode)Command mode (edit mode, copy and

Operations related to directories and files-Previous working directory~ Represents the home directory where the current user identity residesMkdir-p/home/bird/testing Each directory is set up onceRmDir Test Delete Empty directoryRmdir-r test Delete

ObjectiveIn a production environment, we often need to install the operating system on multiple client hosts or servers, and if each is manually installed, Time- consuming and laborious, is obviously unrealistic. So, how to do this kind of work

The importance of regular expressions does not have to be emphasized, as we all know. It should be noted that the regular expression is the row processing tool , it will be matched to the content of a row of the display. Regular expressions are

2.2. Other Rights Management commandsCommand name: chown function: Change the owner of a file directory or fileSyntax: chown[user [file or directory]Command name: chgrp function: Change the owning group of a file or directorySyntax: chgrp[user [file

First,Linux Overview:1. Linux market demand:Linux system Administrator,linux Programmer ( C + +,java,php , jsp ... ), including Linux software engineers and Linux Embedded Development2. Learning process:   1 linux development on the platform ,

Because Linux can be started without a graphical interface, thus saving resources (of course, Linux also has a graphical interface), but also free of charge, such as the enterprise-class CentOS Linux system, but CentOS has recently been acquired by

Command one: PS　　command to view the process that is currently running. You can break and delete unnecessary programs with the KILL command at any time. The PS command is the most basic and powerful process view command that can be used to determine

Typically, programmers connect to a socket (socket) that is two types of contact:(1) streaming sockets (SOCK_STREAM): A connection-oriented socket for connection-oriented TCP service applications;(2) Datagram Socket (SOCK_DGRAM): a non-connected

DHCP Configuration under LinuxDynamic Host Provisioning Protocol (Protocol) is a network protocol for local area networks, and the work protocol is the UDP protocol, which is the function of automatic address assignment to the internal network or

One, gzip toolSecond, bZIP toolsThree, XZ toolsFour, zip and unzipV. TarI, Gzip and zcat (-D,-N)[[Email protected] ~] #gzip-9 install.log//compression level 1~9,1-faster,9-better-rw-r--r--. 1 root root 3719 March 9 10:58 install.log.gz[[Email

This original article belongs to "Linux greenhouse" blog, the blog address is http://roclinux.cn. The author of the article is rocrocket.In order to prevent the vicious reproduction of some websites, special in each article before adding this

Summary of common CentOS commands frequently used by beginners-Ls: displays the current directory file information `ls -a -l`-Cd: Directory jump Cd .. parent directory cd ~ Home Directory cd-Recent directory-Cat: print files, connections, and append

Customized linux System I. Preface Since the birth of linux operating system 1991.10.5, its open source and freedom have been favored by many technical experts. Every linux enthusiast has contributed his/her own efforts, both Linux kernel and