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#??????????}}

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