Bash/KSH/SH Shell: Find The Length Of a String On a UNIX, Linux, BSD, and OS X

While writing a shell script you may want to find out the length of a string. While reading GNU expr command man page I found an interesting option as follows:

expr length STRING

For example display the length of “nixcraft” word/string, enter:

expr length "nixcraft"

OR set it as follows:

var="nixcraft"
expr "${var}" : '.*'

Sample outputs:

8

Finding length of string in bash

The syntax is as follows:

var="nixCraft"
l=${#var}
echo "Length of string \"${var}\" is ${l}."

Sample outputs:

Length of string "nixCraft" is 8.

String length in ksh or older unix oses

You can use the wc command as follows:

## pass the -c option to wc to get the number of bytes in $domain variable ##
domain='www.cyberciti.biz'
echo -n "$domain" | wc -c

Sample outputs:

17

expr and POSIX

Please note that the expr command is not concerned with POSIX (open system standards based on Unix). You can try old good KSH/SH/Bash command as follows which should work with any UNIX-likeo operating systems such as FreeBSD, OpenBSD, Solaris, IBM AIX, HP-UX and more:

myVar="nixcraft"
echo "${#myVar}"

Sample outputs:

8

Another option is to use Perl or Python:

echo "What you seek is seeking you" | perl -nle ' print length '

Sample outputs:

28