Shell

Test script as follows, I mainly want to test $0,$1,$2, $n, [email protected],$* default is what?#!/bin/shEcho ' $1= ' $Echo ' $2= ' $Echo ' [email protected]= ' [email protected]Echo ' $*= ' $*Echo ' $0= 'Test:# sh var.sh 1 2$1=1$2=2[Email

1. Separate each command;Note: The execution of each command will not affect the execution of other commands. In other words, each command executes,However, there is no guarantee that each command will execute successfully.2. Separate && between

Create the user who wrote the file650) this.width=650; "src=" Https://s1.51cto.com/wyfs02/M01/98/E0/wKiom1lBR5_gYB4HAAAoKuZARYU671.png "title=" Screenshot from 2017-06-13 19-44-27.png "alt=" Wkiom1lbr5_gyb4haaaokuzaryu671.png "/>Second, ping 172.25.2

Shell Script Rollup 2 delete files that have been created for more than 32 days#!/bin/bash#date:2017-04-11#version:clear_ballcloud_back_v1.0#contents: removing the  /www /web/ballcloud_bakck/* , if the file is created above 32 day#cd

#!/bin/bash#filename:ifs. SH Data="name,sex,rollon,location"oldifs=$IFSIFS= for inch $data; do Echo Item: $item Done #IFS= $oldIFSSet IFS to, number separator#!/bin/Bash#filename:fenge.SH Line="Root:x:0:0:root:/root:bin/bash"oldifs=$IFSIFS=":"

*: wildcard, matches any character, such as LS *.txt to see all files ending in. txt?: matches any one character#: annotation characters\: escape character for converting special symbols to normal characters, such as Touch \#.txt to create a file

The specific HBase shell commands are shown in table 1.1-1 below:Below we will use the example of "A Student score table" to detail the commonly used HBase commands and how they are used.Here grad for the table is a column, course for the table is a

1. CPU Idle ScriptTop-b-n1 |grep ' Cpu ' |awk ' {print $} ' |sed ' s/%//' |sed ' s/id,//'Assigning values to variablesCpu_id= ' top-b-n1 |grep ' Cpu ' |awk ' {print $} ' |sed ' s/%//' |sed ' s/id,//'Echo $cpu _idIf you only intercept integers, the

1. Use-X to open the Shell script tracking debugging functionEx:bash-x script.shOrSh-x script.sh2. Partial debugging of scripts using Set-x and set +x (input middle content)#!/bin/bash#filename:debug. SH for inch {1.. 6 }; Do -x echo $i

Meaning: Split the file by column according to the delimiterSyntax format: cut [options] ... [File] ...-C, --characters by character-F,--fields by column-D,--delimiter specifies delimiter, default is tab (\ t)Example: viewing file contents Cat

grep: For fuzzy lookups, in standard input or file　　Format: grep [option parameter] ... PATTERN | FILE ...Option parameter Description:- E,--extended-regexp PATTERN is an extensible regular expression-E,--regexp=pattern using PATTERN for matching

Shell scripts can be directly./**.sh, or bash **.shI use the./**.sh to run a script of my own, and the following error will appear:[Email protected]:~$./pixel. SH bash:. /pixel. SH : Insufficient permissions [email protected]: sudo ./pixel. SH

This article mainly introduces the 4 methods of executing shell scripts in Linux, that is, 4 ways to run shell scripts in Linux, and the friends you need can refer to the followingThere are several ways to bash a shell script, and now make a summary.

Linux Command-line edit shortcut: History displays a list of command histories ↑ (Ctrl+p) Displays the previous command ↓ (Ctrl+N) Displays the next command!num executes the command history list of the num-bar command!! Execute the last command!?

The folder does not exist and is createdif [!-d "/data/"];thenmkdir/dataelseecho "folder already exists" fiFile exists then deleteif [!-F "/data/filename"];thenecho "file does not exist" Elserm-rf/data/filenamefiDetermine if a folder existsIf [-d

Tag: Shell expression exists * * * Specify dir DIA statement return resultIf condition statement: The IF condition statement is divided into single branch structure, double branch structure, Multi-branch Structure-------------------------------------

Fourth articleUnderstanding shell command Execution Sequence analysisEach line that the Shell reads from a standard input or script is called a pipe (pipeline); it contains one or more commands, separated by one or more pipe characters (|).In fact,

Today to test a colleague wrote a shell script, execution of the error when the code is "Action:command not found"650) this.width=650; "src=" Https://s4.51cto.com/wyfs02/M02/97/EE/wKioL1k1HGHTyUhuAAAe51KKRyw564.png "style=" float : none; "title="

Regular Expressions           A regular is a way to describe a character or string by combining symbols with special meanings, called regular expressions. Or, the regular is the rule used to describe a class of things. Life is full of regular: two

First, what is the regularA regular is a way to describe a character or string by combining symbols with special meanings, called regular expressions. Or, the regular is the rule used to describe a class of things.Second, grep1. Parameters-N: Show