#!/bin/bash

# This script echoes itself twice to stdout with its lines numbered.

# 'nl' sees this as line 3 since it does not number blank lines.
# 'cat -n' sees the above line as number 5.

nl `basename $0`

echo; echo  # Now, let's try it with 'cat -n'

cat -n `basename $0`
# The difference is that 'cat -n' numbers the blank lines.
# Note that 'nl -ba' will also do so.

exit 0