exif-timestamp

#! /bin/bash

getopt -T &> /dev/null
if [ $? -ne 4 ]; then
  echo "${0##*/}: GNU's enhanced version of getopt is not installed" > /dev/stderr
  exit 1
fi

OPTIONS="z:tr"

PTimeZone=""
PEnableTouch="no"
PEnableRename="no"

ARGS="$(getopt -o "$OPTIONS" -n "${0##*/}" -- "$@")" || exit
eval set -- "$ARGS"

while true; do
  getopts "$OPTIONS" opt || break
  case "$opt" in
    "z")
      PTimeZone="$OPTARG"
      ;;
    "t")
      PEnableTouch="yes"
      ;;
    "r")
      PEnableRename="yes"
      ;;
  esac
done

shift "$(($OPTIND-1))"

if [ $# -lt 1 ]; then
  cat << EOF > /dev/stderr

Touch and/or rename photos based on EXIF timestamp

Usage: ${0##*/} [ <options> ] <filename> [ <filename> ... ]

Options:
  -z	Set EXIF timestamp's timezone (default is the local timezone)
  -t	Enable touch mode
  -r	Enable rename mode

EOF
  exit 1
fi

command="exif"
commandvar="${command//[-.]/_}"
eval "$commandvar"="$(command -v "$command")"
if [ -z "${!commandvar}" ]; then
  echo "${0##*/}: $command not installed" > /dev/stderr
  exit 1
fi

for filename in "$@"; do
  if [ ! -r "$filename" ]; then
    echo "${0##*/}: $filename: file not found or not readable" > /dev/stderr
    continue
  fi
  printf "%-16s    " "$filename"
  exif_datestamp="$("$exif" -t "DateTimeOriginal" "$filename")"
  if [ -z "$exif_datestamp" ]; then
    echo "EXIF entry \"Date and Time (original)\" not found"
    continue
  fi
  unset ExifYear ExifMonth ExifDay ExifHour ExifMin ExifSec
  eval "$(echo "$exif_datestamp" | awk 'BEGIN { FS="[ :]+" } $2=="Value" && $3!="" && $4!="" && $5!="" && $6!="" && $7!="" && $8!="" { printf "ExifYear=%u\nExifMonth=%u\nExifDay=%u\nExifHour=%u\nExifMin=%u\nExifSec=%u\n",$3,$4,$5,$6,$7,$8 }')"
  if [ -z "$ExifYear" -o -z "$ExifMonth" -o -z "$ExifDay" -o -z "$ExifHour" -o -z "$ExifMin" -o -z "$ExifSec" ]; then
    echo "EXIF entry \"Date and Time (original)\" empty or invalid"
    continue
  fi
  ExifTimeStamp="$ExifYear-$ExifMonth-$ExifDay $ExifHour:$ExifMin:$ExifSec $PTimeZone"
  if [ "$PEnableTouch" = "yes" ]; then
    touch -t "$(date -d "$ExifTimeStamp" "+%Y%m%d%H%M.%S")" "$filename"
  fi
  if [ "$PEnableRename" = "yes" ]; then
    filename_dirname="$(dirname "$filename")"
    filename_basename="$(basename "$filename")"
    new_basename="$(date -d "$ExifTimeStamp" "+%Y%m%d-%H%M%S")-${filename_basename##*-}"
    if [ "$new_basename" != "$filename_basename" ]; then
      mv -f "$filename" "$filename_dirname/$new_basename"
    fi
  fi
  date -d "$ExifTimeStamp" "+%Y-%m-%d %H:%M:%S %z"
done.