Shell

Under the Sqlite3 shell, press the UP and DOWN ARROW keys to navigate through the history command, and press the left and RIGHT arrow keys to move the cursor to any character position in the command, so you can modify the wrong statement or the

The printf command is used to format the output and is an enhanced version of the echo command. It is a finite variant of the C-language printf () library function, and is somewhat different in syntax.Note: printf is defined by the POSIX standard,

A detailed description of the regular expressionOrdinary characters: just literal meaningMetacharacters: Meaning beyond the literal meaningBasic regular expression meta-characters and their meanings* The ordinary character before the #0个或多个在 *

From the programmer's point of view, the shell itself is a program written in C language, from the user's point of view, the shell is the user and the Linux operating system communication Bridge. The user can either enter command execution or use

First, the Bash Shell Basic Operations Command 1.type: See if the command is a built-in command of the Bash shell type cd2.Echo: The display of the variable echo $ variable echo name3.unset: Cancels the variable you just set unset name4.Envor SET

Access to a file or directory is divided into read-only, write-only, and executable three types. As an example of a file, a read-only permission means that only the content is allowed to be read, and any changes to it are forbidden. Executable

Like other languages, loops are also script patterns in the shellOne. Grammar:      while  [expression]                  do                   operation ...                  done As long as the expression in [] is set, it will continue to loop.

1. Types of variables in the shellVariables in the shell can be divided into environment variables, positional variables, predefined special variables, and user-defined variables,2. Environment variablesEnvironment variables in the shell are a

wrote a script, mainly do 1, mount the local ISO image file 2, boot local ISO image boot automatically mount 3, configure the local Yum source with ISO image #!/bin/bash#author:wjf#date:2015/04/22#desc:establish a yum on local rhel6.4echo "Please

recently learned Linux system logs and scheduled tasks on the subway coming home from work with inspiration. , try to write your own first script to monitor if there is a malicious login to the server, send an email to notify the administrator. Not

Command substitutionCommand substitution means that the shell can execute commands first, save the output temporarily, and output it where appropriate.Syntax for command substitution:' Command 'Note that it is an anti-quote , not a single quote,

The previous article is a simple script that can be executed and written to the log, but if it is too coarse to put into production, further optimizations are needed:#! /bin/bashif [-D "/OPT/BMC"]; Then if [-F "/opt/bmc/usysfault.log"], then

A. Common Hadoop commands1. The FS command for Hadoop#查看hadoop所有的fs命令Hadoop FS#上传文件 (both put and copyfromlocal are upload commands)Hadoop fs-put jdk-7u55-linux-i586.tar.gz hdfs://hucc01:9000/jdkhadoop fs-copyfromlocal jdk-7u55-linux-i586.tar.gz

Http://wiki.ubuntu.org.cn/Shell%E7%BC%96%E7%A8%8B%E5%9F%BA%E7%A1%80This article LealLicense: Authoring Sharing Agreements GNU Free Documentation License Editorial staff: Firehare, Dbzhang800We can use any kind of text editor, such

3. Run-level scripting introduction3.1. Operating levelOperating level Description:0 Turn off the machine1 Single-User mode2 Multi-user mode, no NFS service3 Multi-user mode4 not currently used5 X startup mode for Windows6 Restart your computerThe

The type of shell that stands in terms of user login:Log-in Shell:Log in normally via a terminalSu-usernameSu-l USERNAMENon-logon Shell:Su USERNAME (using su to switch users without any parameters)Open Command Window under GUIShell scripts that are

We know that the hardware resources of the computer, such as disk, IO, memory are unified management by software, this kind of special software is often said operating system, windows in the underlying resource control based on the building of its

The logical operators of the shell involve the following types, so as long as the appropriate choice, can solve our many complex judgments, to achieve a multiplier effect.First, the logical operator Logical Volume Label Express

Enter HBase Shell Console$HBASE _home/bin/hbase ShellIf you have Kerberos authentication, you need to use the appropriate keytab for authentication (using the Kinit command), and then use the HBase shell to enter the certificate successfully. You

If condition judgment of Linux shell script, linuxshellIF condition judgment1. Basic Syntax:If [command]; thenStatements that meet this conditionFi 2. Extended Syntax: If [command]; then Statements that meet this condition Elif [command];