Shell获取字符串长度

1、${#str}

str="hello"
echo ${#str}

2、awk

str="hello"
echo $str | awk '{ print length($0) }'
or
echo $str | awk -F "" '{ print NF }'

3、wc

str="hello"
echo $str | wc -L
or
echo -n $str | wc -c

4、expr

str="hello"
expr length $str