#!/bin/sh
for f in "$@"; do
    echo "File: $f"
    echo
    pngmeta --quiet "$f" | nawk '
    function output()
    {
	colon = index($0, ":")
	printf "%-16s%s\n", substr($0, 1, colon - 1), substr($0, colon + 2)
    }
    /^Title: / { output(); next }
    /^Author: / { output(); next }
    /^Description: / { output(); next }
    /^Copyright: / { output(); next }
    /^Creation Time: / { output(); next }
    /^Software: / { output(); next }
    /^Disclaimer: / { output(); next }
    /^Warning: / { output(); next }
    /^Source: / { output(); next }
    /^Comment: / { output(); next }
    { printf "%16s%s\n", "", $0 }'
    echo
done
.