语法
for 变量名 in 条件（遍历）; do ...; done
举例
#!/bin/bash
#依次打印出1-4的数值
for i in 'seq 1 4'
do
echo $i
done
#!/bin/bash
#依次打印出1-4的数值
for i in 1 2 3 4
do
echo $i
done
#!/bin/bash
#打印出/usr/local/中的所有文件、目录
for i in ls /usr/local/
do
echo $i
done
for会以空格或者回车作为分隔符，当文件名中包含空格时，遍历会出错
[root@localhost for]# ll
total 0
-rw-r--r--. 1 root root 0 Aug 21 20:16 1
-rw-r--r--. 1 root root 0 Aug 21 20:16 2
-rw-r--r--. 1 root root 0 Aug 21 20:17 3 4.txt
[root@localhost for]# for i in `ls ./`; do echo $i;done
1
2
3
4.txt
[root@localhost for]#
