Linux shell 獲得字符串長度

[root@MAGIC ~]# TEST_CHAR=kkkkkkk

[root@MAGIC ~]# echo $TEST_CHAR | wc -c

8

[root@MAGIC ~]# echo ${#TEST_CHAR}

7

[root@MAGIC ~]#

[root@MAGIC ~]# echo $TEST_CHAR | awk '{print length $0}'

7kkkkkkk

[root@MAGIC ~]# echo $TEST_CHAR | awk '{print length ($0)}'

7

[root@MAGIC ~]# expr length $TEMP_CHAR

expr: syntax error

[root@MAGIC ~]# echo `expr length $TEMP_CHAR`

expr: syntax error



[root@MAGIC ~]# echo `expr length '$TEMP_CHAR'`

10

[root@MAGIC ~]# expr length '$TEMP_CHAR'

10