UNIX for Dummies Questions & Answers

I have written a function that fills an array and another function where if a parameter is supplied it will jump to that part of the array and cat it to the screen.

I need to put in some checks to make sure the parameter supplied is firstly a number and then not a number great than the length of the array. if the user enters no value or anincorrect value it should be ignored and just cats out the entire array.

any ideas?

Code:

!#/bin/ksh
set -A myarr a b hello bye

echo "Enter a number \c"
read var
b=$(echo $var | tr -dc '[0-9]')
if [[ ${#b} -eq ${#var} || $var -le  ${#myarr[*]} ]]; then
   echo "$var is not all numeric characters or too large"
fi

Check this...

Code:

read Input
[[ "$Input" == ?(+|-)+([0-9]) ]] && echo "$Input is numeric"