Linux学习记录-for

for 变量 in 列表;

循环体

done

如何生成列表；

{1..100}

seq [起始数][步长]结束值；

#!/bin/bash

lines=`cat /etc/passwd |wc -l`

for i in `seq 1 $lines`;

do

user=`cut -d: -f1 /etc/passwd | head -$i | tail -1`

echo "hello:$user"

done

输出shell为bash的用户

#!/bin/bash

lines=`cat /etc/passwd |wc -l`

for i in `seq 1 $lines`;

do

#user=`cut -d: -f1 /etc/passwd`

user=`cut -d: -f1 /etc/passwd | head -$i | tail -1`

shell=`cut -d: -f7 /etc/passwd | head -$i | tail -1`

if  grep ‘\<bash\>‘ $shell &>/tmp/out.txt ;then

echo "hello:$user,your shel:$shell"

fi

done

添加删除十个用户

#!/bin/bash

#

if [ $1 == add ]&>/tmp/out.txt ;then

for i in {1..10};do

useradd $i

done

echo "useradd finish"

elif [ $1 == del ]&>/tmp/out.txt ;then

for i in {1..10};do

userdel -r $i

done

echo "userdell finish"

else

echo "please  use add or del"

fi