#!/bin/bash

# This script creates little thumbnail images of jpeg images.
# For my pages I decided to name the smaller images with _small
# before the .jpg, so this script does that too.

if test $# -lt 2 ; then
   echo "usage: $0 scale jpegfile [jpegfile...]"
   echo " (normally, I just type \"thumb 0.2 *\")"
   exit
fi
scale="$1"
shift
for rawname in $* ; do
   if test "${rawname%%.jpg}" = "$rawname"  ; then  # if not a JPEG
      continue;
   fi
   if test "${rawname%%_small.jpg}" != "$rawname"  ; then   # if already is a small
      continue;
   fi
   if test "${rawname%%_zoom.jpg}" != "$rawname"  ; then   # if is a zoom
      continue;
   fi
   echo "converting $rawname"
   djpeg -pnm "$rawname" | pnmscale $scale | cjpeg >"${rawname%%.jpg}_small.jpg"
done