Shell script for fixing non-geotagged photos

geofix.sh

#!/usr/bin/env bash

# Author: Dmitri Popov, dmpop@linux.com

#######################################################################
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#######################################################################

if [ -z "$1" ]; then
  echo "Please specify the file extension"
  echo "For example: " $0 "JPG"
  exit 1
fi

for file in *.$1; do
 GPS=$(exiftool -gpslatitude $file)
 if [ -z "$GPS" ]; then
  echo "$file is not geotagged."
  echo "Coordinates (example: 44.416111,12.201667):"
  read coordinates
  # Extract latitude and longitude from the $coordinates string using the cut tool
  lat=$(echo "$coordinates" | cut -d',' -f1)
  lon=$(echo "$coordinates" | cut -d',' -f2)

  # Calculate the latitude and longitude references
  # The latitude reference is N if the latitude value is positive
  # The latitude reference is S if the latitude value is negative
  # Use the bc tool to compare the value of the $lat variable and assign the correct latitude reference
  if (($(echo "$lat > 0" | bc -l))); then
   latref="N"
  else
   latref="S"
  fi

  # Calculate the correct longitude references for the given longitude value
  # The longitude reference is E if the longitude value is positive
  # The longitude reference is W if the longitude value is negative
  if (($(echo "$lon > 0" | bc -l))); then
   lonref="E"
  else
   lonref="W"
  fi
  # Write the obtained geographical coordinates into EXIF metadata of the file
  echo $lat $lon
  exiftool -overwrite_original -GPSLatitude=$lat -GPSLatitudeRef=$latref -GPSLongitude=$lon -GPSLongitudeRef=$lonref $file
 fi
done