#!/bin/bash
set -x
set -v
# func-cmdlinearg.sh
#  Call this script with a command-line argument,
#+ something like $0 arg1.


func ()

{
echo "$1"
}

echo "First call to function: no arg passed."
echo "See if command-line arg is seen."
func
# No! Command-line arg not seen.

echo "============================================================"
echo
echo "Second call to function: command-line arg passed explicitly."
func $1
# Now it's seen!

exit 0