计算字符长度的方法

1 [root@rhel7-1 test]# aaa="I am a chairman"
2 [root@rhel7-1 test]# echo $aaa
3 I am a chairman
4 [root@rhel7-1 test]# echo ${aaa}
5 I am a chairman

 1 方法一：
 2 [root@rhel7-1 test]# echo ${#aaa}
 3 15
 4 方法二：
 5 [root@rhel7-1 test]# expr length "$aaa"
 6 15
 7 方法三：
 8 [root@rhel7-1 test]# echo ${aaa} | wc -L
 9 15
10 方法四：
11 [root@rhel7-1 test]# echo ${aaa} | awk '{print length ($0)}'
12 15

 1 [root@rhel7-1 test]# cat word_length.sh
 2 #!/bin/bash
 3 #打印字符小于7的单词
 4 
 5 aaa="Dont forget a persons greatest emotional need is to feel appreciated"
 6 for i in $aaa
 7 do
 8         if [ `expr length $i` -le 6 ]
 9         then
10                 echo $i
11         fi
12 done