Shell

The shell script, as its name implies, is a script written for the shell, as long as there is a text editor and an interpreter that can execute the script.There are many types of Shell in Linux, we can open a text editor (can use the Vi/vim command

20171123 Linux Shell Basics Learning Notes1. The beginning of the shellGenerally #!/bin/bash through the #! To uniquely specify the shell path to useThe other # all represents comments.2. Shell variablesDefine variables directly with variablename=

One, variableA variable is a container in which different values can be placed.Key facts:Path,home,pwd,logname these are variables.Example:[[email protected] ~]# echo +ba+~]# echo $a +$b3+4~~ ]# echo $a 3$b4~]# echo $a"3"$b334 The summation of

Classification of regular Expressions:1. Basic Regular Expressions (basic Regular expression also known as basic RegEx abbreviation Bres)2. Extended Regular Expressions (Extended Regular expression also known as Extended RegEx abbreviation Eres),

1.Linux Shell intercepts the first 8 bits of a character variableThere are several ways to implement this: Expr substr "$a" 1 8 echo $a |awk ' {print substr (, 1,8)} ' Echo $a |cut-c1-8 echo $ Expr $a: ' \ (. \ \). echo $

I. Three ways to take random numbers and encrypt them1.random of Fetch and encryptionThe method of taking the number:650) this.width=650; "src=" Https://s3.51cto.com/oss/201711/14/dba3bd986bd100e199cecf8a1067e559.png "title=" Screenshot from 2017-11-

Start, close HBase./bin/start-hbase.sh./bin/stop-hbase.shQuery the HBase version. Its syntax is as follows:HBase (main):010:0> versionBuild tableCreate ' ', ' 'Create ' emp ', ' personal data ', ' professional data 'List all tables: ListTable

One, Shell scriptScript: Can execute the file, after running can implement some function (command stack, non-interactive)Standardize the general composition of shell scripts#! Environmental Statement (Sha-bang)# comment TextExecutable codeSecond,

Recently learning shell programming, a little bit of gadgets to automate the collection of AWR reports, to facilitate problems in the system when troubleshooting.The contents of the script are as follows, the system collects the AWR report from 20 o'

1 Specifications for Shell scripts:1 file suffix is. sh2 first line is the command interpreter: #!/bin/bash3 The first line below the comment write script basic information:Script name, function, writing time, author, contact, etc.2 Shell Execution

Use the conditional function if to compose a shell function called F_judge, which implements the following functions1) when the/home/log directory exists, move the files or directories that start with all TMP in the/home directory to the/home/log

Linux--Shell programming one, regular expression 1, regular expression PK wildcard　　　　　　　　2.Basic Regular Expressions1),*The previous character matches 0 or more times~ grep "A *" Test_rule.txt # matches all content, including blank lines~ grep "aa*"

Previously review:File management, user management, rights Management, Bash's basic featuresFile Management: CP,MV,RMUser

Enterprise Actual combat Problem 8: How to implement the MySQL database for sub-library backup, please use the script to implementMy script

(title): Determine if the incoming parameter is IPIdea: 192.168.1.1is the condition of the IP, * * * dot decimal This four number must be less than 255Dot decimal must be guaranteed to be a number, not a letter#!/bin/bash[ -z $1 ] && echo  "uesage : 

1./dev/null/dev/zero　①/dev/null:/dev/null, called an empty device, is a special device file that discards everything written to it (but reports a successful write operation) and reads it immediately to get an EOF. In Unix jargon,/dev/null is called

Knowledge Points: Array function Local Variables Defining pass-through parameters Example 1:A= (1 2 3) b= (a B c) function () {Local a=$1 local b=$2 for I in $a does echo $i done Ech o $b}funcition "${a[*]}" "${b[*]}" Result: 12

Defining arraysArray name = (value 1 value 2 ...) Value N)[Email protected] ~]# array_name= (value1 value2 value3 value4)Reading an array${array name [subscript]}[Email protected] ~]# Echo"${array_name}"Value1[[email protected]-r3-srv ~]#

Task required: When I need to compress the files in a folder separately:The original code:1 #!/usr/bin/shell2 function Getdir () {3 forElementinch' LS $`4 Do5 #Echo $element6Dir_or_file=$1$element7 8 #Echo $dir _or_file9

Reference URL: http://www.cnblogs.com/chengmo/archive/2010/09/30/1839632.htmlThe Linux shell is much more powerful in programming than Windows batch processing, and cannot be compared in terms of loops, operations, and data types. Here is a summary