#!/bin/bash

FILE="$1";
COMMENT="$2";
COPYRIGHT="Relational pipes (c) $(date +%Y) Frantisek Kucera, Frantovo.cz, GlobalCode.info; copylefted under the GNU FDLv1.3+ license"; # this tag should be in ASCII, see http://www.exiv2.org/tags.html

[ -n "$FILE"    ] && exiv2 -M "set Exif.Image.Copyright $COPYRIGHT" "$FILE";
[ -n "$COMMENT" ] && exiv2 -M "set Exif.Photo.UserComment charset=Unicode $COMMENT" "$FILE";