Shell

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 $

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,

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

If condition test Type: File test, digital test, string testIf statement structure: If ...; Then ...; Fi If ...; Then ...; else ...; Fi Conditional test expression: [Expression]

1. Find the contents of the file (e.g. account number: zh123456): Grep;lsMode 1 Find all Files: grep zh123456 *Mode 2 recursive lookup: ls | Xargs grep zh123456Mode 3 Recursive lookup: Find. -name ' apf44_zswmpay* ' |xargs grep applog|awk-f ": '

In the actual work of small and medium-sized to encounter a problem that is when I go to operate the deployment script, another person can also operate, this how can do, and then the small part of the thought to re-optimize the code, add a process

1) Use if, case, readExample 1:#!/bin/bash#读取终端输入的字符Read-p "Please input a number:" NN1= ' echo $n |sed ' s/[0-9]//g '#使用if语句进行判断if [!-Z $n 1]Thenecho "Please input a number."Exit 1elif [$n-lt 0] | | [$n-GT 100]Thenecho "The number Ranger is

#/bin/bashWork_home=/dataOlddata_home= "${work_home}/olddata"Target_day= ' date-d '-3 day "+%f"#打包前3天的日期目录压缩成功后并删除TAR-ZCVF ${olddata_home}/$target _day.tar.gz ${olddata_home}/$target _dayIf [$?-eq 0];thenecho "The $i is Compression success"RM-RF

The shell is an interface between the user and the system in a Linux system, and it is a high-level programming language, in addition to being the command interpreter. In the Linux command described earlier, the shell appears as a command

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