Shell

The previous article, I said, windows in order to change the user to its console interface, and then start from Windows Vista, plan to change this situation, so there isThe advent of PowerShell.1. Compatible Shell commandsTo be compatible with

EnvlEval will scan two times for subsequent commands, execute this command if the command is a normal command after the first scan, and if the command contains an indirect reference to the variable, the semantics of the indirect reference is

To understand positional variables, first you need to know what a variable is.A variable is a particular string that represents something that is not fixed, and simple to understand is to replace another complex or volatile data with a simple "word".

Shell script for disk partition formattingOur shell scripting structure is divided into sequential structure, selection structure and loop structure, we have previously introduced the selection structure including if, case statements, loop structure

Using Shell operations for a binary conversionAssuming there are some numbers in your script, you need to process those numbers in a different binary. This type of conversion can be implemented easily and automatically using Shell operations. One

All variables in bash are stored as strings, and the ENV command can view the environment variables associated with this terminal process.View environment variables for a process1. Get the PID of the program, such as Java# pgrep Java234922. View the

String test:= =: Test for equality, equality is true, not equal to False! =: Tests are not equal, unequal to true, equal to False>-N String: Tests whether the specified string is empty, empty is true, not empty is false-S string: Tests whether the

To implement Zabbix LLD monitoring, you typically need two scripts, a custom discovery check script, and output in JSON format, and the other is the script to get the valus of the monitoring item.The custom discovery checks script output results in

Shell: ##################################### echo "Time is" date=$ (DATE +%y%m%d) echo $DATE echo "creat a fileder named by Time "Mkdir-p $DATEread-P" input number: "num if [$num-eq] then mv $DATE" Pass "fi#include   #include #include   #include   #

Because of the management of more than 200 Linux servers, a person engaged in the security of so many machines more tired, so after learning the shell script decisive write some common scripts to do some routine maintenance, this article OpenSSH

#!/bin/bashdate_today= ' date-d ' 1 day ago ' +%y%m%d ' #最近7天date_befor_7day = ' date-d ' 7 day ago ' +%y%m%d ' #上一个完整周 (Monday to Sunday) OFD ay= "' Date" +%u "'" "stepofday=" ' Expr $OFDAY + 6 ' "date_befor_weekday=" ' date-d '-' $STEPOFDAY ' Day '

1.find find files that match your search criteriaFind Pathname-options [-print-exec-ok ...]--options:-perm: File lookup permission, plus number-type: File type, plus f: File D: Directory L: Symbolic link file-group: Find files belonging to group

Write a script/root/bin/yesorno.sh, prompt the user to enter Yes or no, and determine whether the user entered Yes or no, or other information #!/bin/bashread-p "Put your answer (yes or no):" Answercase $Answer iny| y| [YY] [EE]                 

One, parenthesis, round brackets () 1, single parenthesis () ① command group. The commands in parentheses will be executed in a new sub-shell sequence, so the variables in parentheses cannot be used by the rest of the script.　　Multiple commands in

Shell programming-------------------lt//less than -GT//greater than >=//equivalent-eq//equals=$#//extract number of parameters$//First parameter$n//extraction of nth parameters$//extract command$? //Store The result of the last execution command, 0

Cluster remote replication (distributed by Namenode)---------------------------------------#! /bin/bashif [$#-lt 1]; Thenecho no argsexit; Fi#get first argumentarg1=$1;cuser= ' WhoAmI ' fname= ' basename $arg 1 ' dir= ' dirname $arg 1 ' If ["$dir" =

Custom variables: There are variables that are defined by the system user, only valid in the user's own shell environment, also known as local variables, and when shell scripting is programmed, certain custom variables are usually set to suit the

First, calculate the value of 1+2+...+100Use the General method:   #! /bin/bash      sum=0   res= ""     num=1   for  ((;  numThe results are as follows:650) this.width=650; "src="

Refer to "Linux command, editor and Shell Programming" (Tsinghua University Press)When you start the shell, it runs the startup file to initialize itself. Which file to run depends on how the shell interacts with a login shell or a non-landing shell

Array, arraysVariable: Stores the memory space of a single element;Array: Memory space for storing multiple elements;Array name: The entire array has only one name;Array index: numbering starting from 0;Array name