Shell Learning Path: Process Control (for)

Syntax for the FOR loop:

1. For variable in value 1 value 2 value 3 ....

Do

Program

Done

For example: The following script will print 4 times respectively the value of morning noon afternoon evening

1 #!/bin/bash2#打印时间 3#Author mrfeng45   for-time in morning noon afternoon evening6do         7                  Echo $time8          Done

For example, batch decompression:

1#!/bin/Bash2 #批量解压缩脚本3 #Author: Mrf4 5path=/opt/Lamp6 7 CD $path8 9 ls*.Tar. gz >ls. LogTen ls*.tgz >>ls. Log One  forIinch$(Cat ls. Log) A          Do -                 TarZXVF $i &>>cc. Log -          Done the RM-rfls. Log

2.for Syntax Two

Format:

1  for (initial value; cyclic control condition; variable change)) 2      Do 3            procedure  4      Done

For example:

1#!/bin/Bash2 #从1加到1003 4s=05  for((i=1; i<= -; i=i+1))6      Do7s=$ (($s +$i))8      Done9 Echo "The sum of 1+2+...+100is: $s"

Example: adding Users in bulk

1#!/bin/Bash2 # Users who add a number of users in bulk3# AUTHOR:MR F (e-mail:22222222)4 5Read-p"Please input user name:"-T -name6Read-p"Please input the number of users:"-T -Num7Read-p"Please input the password of users:"-T -Pass8 if[!-Z"$name"-A! -Z"$num"-A! -Z"$pass" ]9          ThenTeny=$ (Echo$num |sed 's/[0-9]//g') One                 if[-Z"$y"] ; Then A                          for((i=1; i<= $num; i=i+1)) -                                  Do -/usr/sbin/useradd $name $i &>/dev/NULL the                                         Echo$pass | /usr/bin/passwd--stdin $n -Ame$i &>/dev/NULL -                                  Done -                 fi + fi - Cat/etc/passwd|grepuser[1-$num] |Cut-D":"-F1>>userlist.log

Of course, I also wrote a script that uses Userlist.log for bulk deletion to make it easier for you to clean up after the experiment.

1 #!/bin/bash2 for in $ (cat ./Userlist.log)3 do         4                 /usr/sbin/userdel-r $i &>>del.log5          Done 6 #cat  del.log7rm -RF Del.log

Shell Learning Path: Process Control (for)