#! /bin/sh
# Program to rename picture files with .jpg extensions sequentially
# 2 command line parameters are allowed, the base name, and optionally a start
# count
#
# procedure:
#
#   1)  place yourself in the directory where your pictures are.
#   2)  type: picnamer fred 13
#
#   Picnamer will rename all *.jpg files fred_xxx.jpg
#   in your directory beginning with fred_013.jpg.
#
#   If the second command line argument is missing, the count will
#   begin at 1.
#
#   If the first command line argument is missing, the pictures will be
#   named px_xxx.jpg beginning at px_001.jpg
#
#   The standard output produces a sed file to allow the pictures to be
#   renamed back to their original name.
#
###############################################################################

DATE=`date +%y%m%d`

#If a parameter is given ($# >= 1), we accept it as the prefix
if [ "$#" != "0" ]; then
    PREFIX=$1_
else
    PREFIX="px_"
fi

#If a second parameter is given, we assume it is a target prefix
if [ $# -gt 1 ]; then
    LOOP=$2
else
    LOOP=1
fi


echo "# jpgnamer's revert sed file"
echo

# Process the jpg or jpeg files
for file in  *.jpg
do
    if [ "$file" != "*.jpg" ]; then
if [ $LOOP -lt 10 ]; then
    file2=${PREFIX}00$LOOP.jpg
else   
    if [ $LOOP -lt 100 ]; then
file2=${PREFIX}0$LOOP.jpg
    else   
file2=${PREFIX}$LOOP.jpg
    fi
fi   
if [ -f $file2 ]; then   # If file2 exists, copy it with date stamp
    cp "$file2" "$file2.$DATE"
fi
mv "$file" "$file2"    # rename the file
# Increment the counter
LOOP=`expr $LOOP + 1`
echo "s/$file2/$file/"
    fi
done
echo
echo "# End of sedfile"
exit 0