Simple usage information for shell scripts

usage

#!/bin/sh
# Usage documentation and program description go here,
# nicely formatted and laid out to fit 78 columns.

# NOTE: The blank line above is the end of the file comment header.

# Check command-line options
if true; then
	# Display the file comment header.
	sed -n '2,/^$/s/^# //p' "$0"
	exit
fi