#!/bin/bash -x

if [ $1 == "" ] ; then
    echo "Укажите расширение файла, например JPG или png"
    exit 1
fi


if [ $2 == "" ] ; then
    echo "Укажите нужный размер, например 400x300"
    exit 1
fi


DST=`mktemp -d -p .`

for i in *.$1 ; do
    convert -verbose -resize $2 $i $DST/$i
done


if [ $3 != "" ] ; then
## initialise counter
counter=1

## find all JPG files to be renamed
find $DST -type f -name '*'|while read l_orig
do
   if [ $counter -lt 10 ]
   then
      mv "$l_orig" "$DST/$3_000${counter}.jpg"
   else
      if [ $counter -lt 100 ]
      then
         mv "$l_orig" "$DST/$3_00${counter}.jpg"
      else
         if [ $counter -lt 1000 ]
         then
            mv "$l_orig" "$DST/$3_0${counter}.jpg"
         else
            mv "$l_orig" "$DST/$3_${counter}.jpg"
         fi
      fi
   fi

   ## Increment counter
   counter=`expr $counter + 1`
done

fi