best shell scripting book

"######---Number of CPU threads---#######" echoprocessor=' echo $CPU ' if[ $CPU -eq4];then ' echo ' wa= $WA andid= $ID Cpuprocessorisok "|mail-s" $HOST cpu "[emailprotected] ' Else ' echo "wa= $WA andid= $ID cpuprocessorhaveproblem" |mail -s "$HOST cpu" [emailprotected] ' fiecho "######---CPU ID---#########" echo Cpu~id= ' echo $ID ' echo ' ######---CPU wa---######### ' echocpu~wa= ' echo $WA ' echo ' ###### ---CPU load---####### "echocpu-load= ' echo $LOAD ' if[ $LOAD >0.05];then ' echo ' cpu

variable), returns the old value to the variable after the result has been generated, and then executes the variable plus 1 operation. In contrast, in the prefix (prefix), the operand is placed in front of the variable, the variable is added 1, and then return the new value to the variable,--the working method and + + is similar, but its operation is to reduce the variable by 1.7. Exit statusEach command exit returns a small integer value to the program that refers to it, which is the well-know

Tags: shell script1, write script/root/bin/systeminfo.sh, display the current host system information, including hostname, IPV4 address, operating system version, kernel version, CPU model, memory size, hard disk size#!/bin/bashecho "hostname: `hostname`"echo "ipv4 addr: `ifconfig |egrep -o "\2, scripting/root/bin/backup.sh, can be implemented to backup/etc/directory to/ROOT/ETCYYYY-MM-DD#!/bin/bashecho "co

-be-sustained by perpetual neglect of many and other things. Robert Louis Stevenson (1850-1894) [Email protected]:~/shell/26zhang$ Note this:#grep "$ (date +%b '%-d, '%Y)"-A2 |Since my Ubuntu is in Chinese, I have not been searching for November. I'm going to replace it with this one, only 28, 2017.grep ", $ (date +%y)"-a2 | # Xcy AddIt would have been like this grep "$ (date +%-d, '%Y)"-A2 | # xcy Add, don't know why my date is 29. And the site is

Bash shell scripting Getting Started (ii)Use of the Read commandRole:Use read to assign the input value to one or more shell variables:-p Specifies the prompt to display-T TIMEOUTRead reads the values from the standard input, assigns a variable to each word, and all the remaining words are assigned to the last variableEx.read-p "Enter a filename:" FILE650) this.w

Shell scripting improves Date//view dates and times-S change Time date-s "2015-08-20 14:27:12"View time Date + "%y-%m-%d%h:%m:%s"-D Change Single time Date-d "-2 Days" +%f+%w Show weeks+%w show how many weeks this yearntpdate //Calibration time ntpdate ntp.fudan.edu.cn use Fudan University server proofing time. Need to install NTP packagecal //view calendar of the month-y view calendar throughout the yearBu

"Li Songyang writing"User= ' WhoAmI 'Case $user inRootecho "Hello root";;Teacherecho "Hello teacher";;*)echo "Hello $user, welcome"Esac echo "Date and Time: ' Day '"echo "This month's calendar: ' Cal '"echo "Machine Name of the machine: ' Uname-n '"echo "Current name and version of this operating system: ' Uname-s;uname-r '"echo "List of all files in the parent directory: ' ls '. /`"echo "Root is running all processes: ' Ps-u root '"echo "Variable term value: $TERM"echo "Variable PATH value: $P

free space on the remote server is larger than the total DMP file capacity of the current day on the local server, copy the DMP file to this disk, otherwise, Just execute the continue command in the Else statement, which jumps out of the inner for Loop, reads off a disk, and copies the DMP file to the next disk.Then, the SCP command during the execution of the replication progress percentage is changed at all times, the process is not directly written to the log file, do not believe everyone to

Text processing commands for Shell scripting Learning notesA. Cut (truncate text characters or field fields)Command format: Cut [option] FileCombined use of 1.-d and-F to intercept fieldsDescription: * denotes delimiter, such as-,:, empty characters, etc.n Denotes nth fieldUsage One: cut-d*-fn to intercept a field from the text for each line that is delimited by a particular symbolExample: Cut-d:-f1 interce

file is a script that is executed when the Linux system startsEdit the Inittab file (use the Vim/etc/inittab command to open the file)Example: Add a statement to the Inittab file to allow the system to execute a shell script file that checks the system disk when it starts checkdisk.shcheckdisk::once:/sbin/checkdisk.sh >/dev/console 2>1 indicates that this command is executed at each runlevel, if it is to be developed at the third run level: Checkdisk

First, the basic writing process of the practice script:1. Determine the task and the command to complete the task2. Scripting Integration Tasks3. Authorization and test executionSecond, exercise:A. First I create a directory, put the script we write into, so it's not too messy[Email protected] ~]# mkdir-p/root/bin[Email protected] ~]# Cd/root/binB. Start compiling below[Email protected] bin]# VI sysinfo.sh#!/bin/bash # #从/etc/shells Select a

, which is represented as a local variable. such as local temp=1 .Example 3. Array Parameterstest3.sh#!/bin/bash Span class= "hljs-comment" ># trying to pass a array variable function testit {local newarray # use ' local ' define a local variable newarray= (' echo " the NewArray value is ${newarray[*]} "}myarray= (1 , 2 , 3 , 4 , 5 ) echo "the original array is:${ Myarray[*]} " testit $myarray Test:sh test3.shOutput:The original array is:1,2,3,4,5The NewArray value is 1,2,3,4,5Example

I. DEFINITION of format[Function] Function name (){Command table}Ii. Method of InvocationFirst define, then use, direct input function name, no parentheses required ()Three, function parameter transfer methodCan be passed using positional parameters or variables#!/bin/bash# myfirst.shtestfunction () {echo"$1,$2" #positional parameter passing parametersEcho"$val 1, $val 2" #Variable pass parameter}val1="test1"Val2="test2"testfunction1 2#calling FunctionsEcho"$1,$2" #positional parameters passed

condition.ArrayBefore looking at the for and case statements, let's look at the shell arrayPresentation mode:Mode one: arraynum= (1 2 3 4 5)Way two:Arraynum[0]=0Arraynum[1]=1arraynum[2]=2How to get the length of the array: ${#arraynum [@]} (arraynum[@] actually arraynum the list, counting the symbols we talked about earlier, so this expression is not difficult to understand)In statementAnd then we'll see how to iterate through the output array 1 #!

Shell commandsThis problem, a command with a shell script is sufficient:awk ‘{print $1}‘ 1.log | sort -n | uniq -c | sort -nExplain: The awk command is advantageous in terms of fragmentation, where {print} prints the first paragraph, and awk can specify the delimiter with-F, and if you do not specify a delimiter, the default is a blank character (such as a space, tab, and so on), where the

to access badfile: No file or directoryIf you need to redirect both standard output and standard errors to a file, separate processing is required, such as:ls 2 1> TestThis redirects the error prompt and the standard output to a different file. The bash Shell provides a special redirect > can redirect the output of stderr and stdout to the same file. (3) Redirect output in script temporary re-training: If you need to convert stdout messages to stderr

legitimate email address, the work can be done in the Web page JavaScript, or in the website backstage program, such as PHP, Perl, Python, Ruby, Java, or C, all these words? Support for regular expressions, it can be said that the current programming language does not support regular expressions is very rare. In addition to the programming language , many UNIX commands and tools also support regular expressions such as grep, VI, SED, awk, Emacs, and so on. a regular expression, like a variable

Shell implementation of multi-level menu scriptingOriginal: https://www.yuanmas.com/info/2gOwBPvqyb.htmlThis article mainly introduces the shell implementation of multi-level menu system Installation script instance sharing, this script with multi-level menu to achieve lamp, LNMP installation display effect, the need for Friends can refer to:Hint: This script mainly realizes multi-level menu effect, and doe

/etc/crontab Add the following code: Here's an example of an hourly 26-minute execution: * * * * * root/home/**/wewang/autobackupmysql_qas.sh If executed at three O ' Day, then: XX 3 * * * root/home/**/wewang/autobackupmysql_qas.sh Case 2:redhat situation. ( that is, the currently used Linux system ) Copy the script you just edited to the appropriate directory [Email protected]***** wewang]# CP autobackupmysql_qas.sh/etc/cron.daily/ As follows: parsing : Th

$n/awk/if statementsvim/server/scripts/bc.shIf [$#-ne 2];thenecho "Usages:you can only write words"ExitFiAwk-va=$1-vb=$2 ' Begin{print a+b "\ n" a-B "\ n" a \ "\ n" \ A} '1.9.2 using the For statement to turn off useless servicesvim/server/scripts/chk.shoff=chkconfig |awk ‘!/crond|network|sshd|rsyslog|sysstat/{print $1}‘For DQF in $offDoChkconfig $DQF offDone1.9.3 Variable Assignment methodMethod 1-Assign a normal variable--restart invalid normal variable cannot be run in scriptA=xecho $a env V