Used to synchronize photos between a syncthing share folder and an actual Photos folder

sync-photos.sh

#!/usr/bin/env bash

# Synchronize two photo folders using rsync.
# * Handles moves by:
#    1. See if a file to be synched is already on target (with the same name)
#    2. If file is already on target, compare checksums.
#     2a- If checksums match, it was a file move, so delete file from target
#     2b- If checksums don't match, we are possibly talking about different files
# * Deletions are not synchronized to keep all files on target

SRC="$1/"
DST="$2/"

DUPS_TO_DEL=()

if [ ! -d "$SRC" ]; then
  echo "ERROR: source folder '$SRC' does not exist"
  exit 1
fi

if [ ! -d "$DST" ]; then
  echo "ERROR: destination folder '$DST' does not exist"
  exit 1
fi

# find files to be copied
MOD_FILES=$(/usr/bin/rsync -ain --ignore-existing "$SRC" "$DST"  | egrep '^>' | cut -f 1 -d ' ' --complement)

while IFS= read -r f; do
  # get the filename with extension
  FILE_NAME=$(basename "$f")

  # returns something if filename is already present on $DST
  FIND_RESULTS=$(/usr/bin/find "$DST" -type f -name "$FILE_NAME")
  if [ ! -z "$FIND_RESULTS" ]; then
    while IFS= read -r DST_FILE; do
      SRC_MD5=$(md5sum "$SRC/$f" | awk '{print $1}')
      DST_MD5=$(md5sum "$DST_FILE" | awk '{print $1}')
      # do a md5 comparison
      if [ "$SRC_MD5" == "$DST_MD5" ]; then
        DUPS_TO_DEL+=("$DST_FILE")
      fi
    done <<< "$FIND_RESULTS"
  fi
done <<< "$MOD_FILES"

# perform the actual sync
/usr/bin/rsync -av "$SRC" "$DST"

if [ ${#DUPS_TO_DEL[@]} -ne 0 ]; then
  echo
  echo "Duplicated files to be removed on destination path '$DST':"
  echo "${DUPS_TO_DEL[@]}"
  /usr/bin/rm -v "${DUPS_TO_DEL[@]}"
fi