showing file thumbnails in terminology

lsthumb.sh

#!/bin/sh

WIDTH=10
HEIGHT=4
LABEL="yes" # show filename under thumbnail
VIDEO="no"  # don't show video thumbnail. only show generic icon
CHAR="."

if [ ! "$TERMINOLOGY" = "1" ]; then
   echo "This script only works in Terminology" >&2
   exit 1
fi

while getopts ":w:h:nv" opt; do
   case "$opt" in
      w) WIDTH="$OPTARG" ;;
      h) HEIGHT="$OPTARG" ;;
      n) LABEL="no" ;;
      v) VIDEO="yes" ;;
      :)
         echo "Option -$OPTARG requires a value" >&2
         exit 1
         ;;
   esac
done

shift $((OPTIND - 1))

if [ $WIDTH -lt 1 ]; then
   WIDTH=10
fi

if [ $HEIGHT -lt 1 ]; then
   HEIGHT=4
fi

if [ -z "$*" ]; then
   PARAM="./*"
else
   PARAM=$*
fi

function get_info {
   local ORIG_STTY="$(stty -g)"
   stty -echo
   echo -ne "\e}qs\0"
   read RESPONSE
   stty "$ORIG_STTY"

   TERM_WIDTH="$(echo "$RESPONSE" | cut -d';' -f1)"
   TERM_HEIGHT="$(echo "$RESPONSE" | cut -d';' -f2)"
}

function print_block {
   echo -ne "\e}ib\0"
   for (( c = 0 ; c < $WIDTH ; c++ )); do
      echo -n "$CHAR"
   done
   echo -ne "\e}ie\0"
}

# $1 = path
function declare_inline_media {
   echo -ne "\e}it$CHAR$WIDTH;$HEIGHT;$1\0"
}

# $1 = direction (left/right/up/down)
# $2 = amount
function move {
   local OP
   case "$1" in
      left)  OP="D" ;;
      right) OP="C" ;;
      up)    OP="A" ;;
      down)  OP="B" ;;
   esac
   echo -ne "\e[${2:-1}$OP"
}

# $1 = absolute path
function get_thumb {
   if [ -d "$1" ]; then
      THUMB="folder"
   else
      EXT="${1##*.}"
      # there are still more file formats supported by terminology.
      # these are just few i used most
      case "$EXT" in
         jpg|jpeg|png|gif|bmp|ico|xcf|svg|pdf)
            THUMB="$1";;

         avi|mp4|mkv|asf|wmv|ogv|mpg|rmvb|flv)
            if [ "$VIDEO" = "yes" ]; then
               THUMB="$1"
            else
               THUMB="video-x-generic"
            fi
            ;;

         mp3|aac|flac|ogg|wma|wav|ape)
            THUMB="audio-x-generic" ;;

         zip|rar|ace|gz|bz2|tbz2|tgz|cbz|cbr|7z|xz)
            THUMB="application-x-archive" ;;

         txt|srt|edc|c|h|sh|py|rb|lua|go|php|cpp|h|hpp|cc|hh|md|vim|conf|ini|am|ac|in|xml|html|xhtml|rss|atom|README|TODO|NOTES|ChangeLog|NEWS|AUTHORS|COPYING|INSTALL)
            THUMB="text-x-generic" ;;

         *) THUMB="empty";;
      esac
   fi
}

get_info

COL=1
for FILENAME in $PARAM; do
   ABSPATH="$(realpath "$FILENAME")"
   BASENAME="$(basename "$ABSPATH")"

   get_thumb "$ABSPATH"

   declare_inline_media "$THUMB"

   for (( ROW = 0 ; ROW < $HEIGHT ; ROW++ )); do
      print_block
      move left $WIDTH
      move down
   done

   if [ "$LABEL" = "yes" ]; then
      CAPTION="${BASENAME:0:$WIDTH}"
      LEFT_PAD=$(( ($WIDTH + ${#CAPTION}) / 2 ))
      printf "%*s" $LEFT_PAD "$CAPTION"
      move left $LEFT_PAD
   fi

   COL=$(( $COL + $WIDTH + 3 ));

   if [ $COL -ge $TERM_WIDTH ]; then
      COL=1
      if [ "$LABEL" = "yes" ]; then
         echo
      fi
      echo
   else
      move right $(( $WIDTH + 2 ))
      move up $HEIGHT
   fi

done

if [ $COL -gt $WIDTH -a $COL -lt $TERM_WIDTH ]; then
   move down $HEIGHT
   if [ "$LABEL" = "yes" ]; then
      echo
   fi
fi
echo