Linux Shell编程简单实例讲解

#!/bin/bash

i=0
while [ $i -lt 50 ];do
   let i=i+1
   mkdir -p /userdata/$i
   chmod 754 /userdata/$i
done


#!/bin/bash

for ((i=1;i<=50;i++));do
   mkdir -p /userdata/$i
   chmod 754 /userdata/$i
done


#!/bin/sh


for D in user{1..50}
do
mkdir -m 754 -p $D
done


echo -e "`date`\n`cat ABC.txt`" > ABC.txt
echo "`date | cat - ABC.txt`" > ABC.txt
sed -i "1i`date`" ABC.txt