creates a XML file for wallpaper slideshow

ubuntu-wallpaper-slideshow.sh

#!/bin/sh
#
# ubuntu-wallpaper-slideshow.sh - creates a XML file for wallpaper slideshow
#
# Creates a XML file like /usr/share/backgrounds/contest/precise.xml
# in Ubuntu 12.04.
#
# Usage example:
# ./ubuntu-wallpaper-slideshow.sh ~/Pictures/LOOK/*.jpg > LOOK.xml
#
# You have to create another XML file manually in
# /usr/share/gnome-background-properties directory to use the
# generated XML file.
#
# Seungwon Jeong <[email protected]>
#
# Copyright (C) 2012 by Seungwon Jeong
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see
# <http://www.gnu.org/licenses/>.

set -e

set -u

if test "$#" -lt 2; then
    echo "Usage: $0 <WALLPAPER1> <WALLPAPER2> [...]"
    exit 2
fi

for file; do
    if test ! -f $file; then
        echo "$file: No such file" 1>&2
        exit 1
    fi
done

echo '<background>'

echo '  <starttime>'
echo '    <year>2009</year>'
echo '    <month>08</month>'
echo '    <day>04</day>'
echo '    <hour>00</hour>'
echo '    <minute>00</minute>'
echo '    <second>00</second>'
echo '  </starttime>'

static_duration=1795.0
transition_duration=5.0

first_file=`realpath "$1"`
shift

echo '  <static>'
echo "    <duration>$static_duration</duration>"
echo "    <file>$first_file</file>"
echo '  </static>'

echo '  <transition>'
echo "    <duration>$transition_duration</duration>"
echo "    <from>$first_file</from>"

for file; do
    file=`realpath "$file"`

    echo "    <to>$file</to>"
    echo '  </transition>'

    echo '  <static>'
    echo "    <duration>$static_duration</duration>"
    echo "    <file>$file</file>"
    echo '  </static>'

    echo '  <transition>'
    echo "    <duration>$transition_duration</duration>"
    echo "    <from>$file</from>"
done

echo "    <to>$first_file</to>"
echo '  </transition>'

echo '</background>'