: help
:
# squish-png requires a source PNG positional argument even with -h (it
# only short-circuits to the help/syntax text once argument parsing sees
# a non-empty source name), so pass a dummy filename that's never actually
# opened -- -h prints the syntax text and returns before any file I/O.
# Confirms the executable builds, links against libpng, and runs.
#
$* -h dummy.png >!
