for

普通用法

#!/bin/bash

for i in 1 2 3 4 5
do
    echo $i
done

批量解压

#!/bin/bash

cd /root/logs
ls *.tar.gz > ls.log
for i in $(cat ls.log)
do 
    #放入回收站，不输出什么
    tar -zxf $i & > /dev/null
done
rm -rf /root/logs/ls.log

while

1+到100

#!/bin/bash

i=1
s=0
while [ $i -le 100 ]
do
    s=$(($i+$s))
    i=$(($i+1))
done
echo $s

until

#!/bin/bash

i=1
s=0
until [ $i -gt 100 ]
do
    s=$(($s+$i))
    i=$(($i+1))
done
echo $s