#!/bin/sh
#
# pngcrush_batch  png png png...
#
# Run pngcrush batch-wise over a list of png files,
# to compress them by the maximum amount without dataloss.
#
tmp=/tmp/pngcrush_batch_$$.png
if [ -f $tmp ]; then
  echo >&2 "pngcrush_batch: temp file \"$tmp\" already exists -- ABORTING"
  exit 1
fi
trap 'rm -f $tmp ; exit 0' 0 1 2 3 15

for i in "$@"; do
   echo "--------------------------------------"
   echo "$i"
   echo "--------------------------------------"
   pngcrush "$i" $tmp
   if [ $? -eq 0 -a -s $tmp ]; then
     mv $tmp "$i"
   else
     echo >&2 "Pngcrush failed for file \"$i\" -- ABORTING"
     exit 1
   fi
done