uxwspr60:/home/orcimp> cat test.sh alpha='abcdefghijklmnopqrstuvwxyz' print ${alpha:5:5} uxwspr60:/home/orcimp> test.sh test.sh[2]: ${alpha:5:5}: The specified substitution is not valid for this command.

$ cat test.sh #!/bin/bash alpha='abcdefghijklmnopqrstuvwxyz' echo ${alpha:5:5}

The bash syntax ${alpha:5:5} will not work on HP-UX.  Following are 4 solutions that will provide the fghij result when $alpha is 10 characters or longer.  But when $alpha is less than 10 characters, they produce different results! For the sed solution below, if $alpha is less than 10, sed outputs the string as is with no change: echo $alpha | sed 's/^.....\(.....\).*/\1/' For expr, if $alpha is less than 10, output will be null: expr $alpha : ".....\(.....\)" For the ksh variable manipulations below, if $alpha is less than 10, output will be null: alpha=abcdefghijklmnopqrstuvwxyz beyond10=${alpha#??????????} first10=${alpha%$beyond10} last5=${first10#?????} echo $last5 For those same variable manipulations - but nested all together, if $alpha is less than 10, it will still output the shorter-than-5 substring. echo ${alpha#?????%${alpha#??????????}}