Re: Verifying numeric values

[Andy Chu]

On Mon, Oct 18, 2021 at 8:44 PM tolugboji via <help-bash@gnu.org> wrote:
>
> Would like to validate a numeric value (from 1 to 255, for use with terminfo).

Try this:

is_valid() {
  local x=$1
  local b=$(( 1 <= x && x <= 255 ))
  return $(( ! b ))   # 0 is true, 1 is false
}

$ is_valid 256; echo $?
1
$ is_valid 3; echo $?
0