Swayimg: add the ability to navigate to the other images in the folder, starting at the selected image

swayimg.sh

#!/usr/bin/env bash

# Swayimg: add the ability to navigate to the other images in the folder,
# starting at the selected image or the first image by default.
#
# Links:
#      https://gist.github.com/willemw12
#      https://github.com/artemsen/swayimg

SWAYIMG_FIND_OPTS="${SWAYIMG_FIND_OPTS:--maxdepth 1}"
#SWAYIMG_SORT_OPTS="${SWAYIMG_SORT_OPTS:-}"

####

if (( $# == 0 )); then
  printf "usage: [SWAYIMG_FIND_OPTS=<OPTION>...] [SWAYIMG_SORT_OPTS=<OPTION>...] %s [<SWAYIMG_OPTION>...] <FILE|FOLDER>\n" "${0##*/}" >&2
  exit 1
fi

FILE="${*:$#:1}"
REST_ARGS=("${@:1:$#-1}")

SWAYIMG_OPTS=(--order=none)

# shellcheck disable=SC2048,SC2086
if [ -d "$FILE" ]; then
  readarray -d '' FILES < <(find -L            "$FILE"   ${SWAYIMG_FIND_OPTS[*]} -mindepth 1 -type f -print0 | sort ${SWAYIMG_SORT_OPTS[*]} -z)
elif [ -f "$FILE" ]; then
  readarray -d '' FILES < <(find -L "$(dirname "$FILE")" ${SWAYIMG_FIND_OPTS[*]} -mindepth 1 -type f -print0 | sort ${SWAYIMG_SORT_OPTS[*]} -z)

  # Rotate the filenames in the FILES array to make FILE the selected file for swaymg,
  # i.e. make it the first file in the array.

  I=0
  for F in "${FILES[@]}"; do
    [ "$(realpath "$F")" = "$(realpath "$FILE")" ] && break

    HEAD+=("$F")
    (( I++ ))
  done

  # File not found
  (( I == ${#FILES[@]} )) && exit 0

  for F in "${FILES[@]:I:${#FILES[@]}}"; do
    TAIL+=("$F")
  done

  FILES=("${TAIL[@]}" "${HEAD[@]}")
else
  exit 1
fi

(( "${#FILES[@]}" > 0 )) || exit

exec swayimg "${SWAYIMG_OPTS[@]}" "${REST_ARGS[@]}" "${FILES[@]}"