#!/bin/bash
# slideshow - Display a slideshow of photos from the specified directory. 
#             Uses ImageMagick's "display" utility.

setglobal delay = '2'			# default delay in seconds
setglobal psize = '"1200x900>'"	# preferred image size for display

if test $Argc -eq 0  {
  echo "Usage: $[basename $0] watch-directory" > !2 ; exit 1
}

setglobal watch = $1

if test ! -d $watch  {
  echo "$[basename $0]: specified watch directory $watch isn't a directory" > !2 ; exit 1
}

cd $watch

if test $Status -ne 0  {
  echo "$[basename $0]: failed trying to cd into $watch" > !2 ; exit 1
}

setglobal suffixes = $[file * | grep image | cut -d: -f1 | rev | cut -d. -f1 | \
   rev | sort | uniq | sed 's/^/\*./]

if test -z $suffixes  {
  echo "$[basename $0]: no images to display in folder $watch" > !2 ; exit 1
}

/bin/echo -n "Displaying $[ls $suffixes | wc -l] images from $watch "
set -f ; echo with suffixes $suffixes ; set +f

display -loop 0 -delay $delay -resize $psize -backdrop $suffixes

exit 0