terminal: Create module to consolidate term utils

Terminal application, a variety of shell configurations, terminal file
and session management all consolidated in one place.

terminal/.config/vifm/scripts/vifm-thumbnailer

@@ -0,0 +1,115 @@
+#!/usr/bin/env bash
+
+show_help() {
+    printf """
+vifm-thumbnailer
+
+Easily show images/thumbnails from the vifm file manager.
+
+Usage:  vifm-thumbnailer <current file>
+
+Point it to a file whose directory you want thumbnailed.
+If you point it to a directory itself, it will list its contents.
+
+Options:
+
+    -h      Display this help.
+
+    -r      Show images recursively from current folder.
+
+    -t      Open viewer in thumbnail mode.
+
+    -m      Show thumbnails for video files in addition to image files.
+            Will take longer to load up and requires ffmpeg utilities.
+
+Vifm:
+
+    If the file is on your path (e.g. in ~/.vifm/scripts) from within
+    vifm you can run the script by invoking it with:
+    \`:!vifm-thumbnailer \%%c\`
+    which will show all directory thumbnails with the current file
+    initially shown.
+
+    If you want to have vifm show a filtered view for selected files
+    afterwards add a \%%u to the command.
+
+"""
+}
+
+TMPDIR="$(mktemp -d)"
+valid_files_tmp="$TMPDIR/nsxiv_rifle_$$"
+
+# get all files in directory
+list_img_files() {
+    if exist fd; then
+        fd --max-depth="$maxdepth" -tf . "${1%/*}" | is_img_extension | sort | tee -a "$valid_files_tmp"
+    else
+        find -L "${1%/*}" -maxdepth "$maxdepth" -type f -print | is_img_extension | sort | tee -a "$valid_files_tmp"
+    fi
+}
+
+list_vid_files() {
+    # shellcheck disable=2016
+    find "${1%/*}" -mindepth 1 -maxdepth "$maxdepth" \( -type f -o -type l \) -printf "%P\0" |
+        xargs -r0 -n 20 -P 64 file -00 -L --mime-type -- |
+        xargs -r0 -n 2 sh -c '
+            case "$2" in
+                video/*) printf "%s\0" "$1";;
+            esac
+        ' -- |
+        sort -z |
+        xargs -r0 -I FILE ffmpegthumbnailer -i FILE -o "$TMPDIR/FILE.jpg" -m -s 384
+    find -L "$TMPDIR/" -maxdepth "$maxdepth" -type f -print | sort | tee -a "$valid_files_tmp"
+}
+
+img_ext="jpe?g|png|gif|svg|webp|tiff|heif|avif|ico|bmp"
+is_img_extension() {
+    grep -iE "\.($img_ext)$"
+}
+
+# TODO if marking video thumbnail - will use wrong temporary path on output, makes e.g. vifm %u not work
+open() {
+    trap 'rm -rf -- $TMPDIR' TERM INT EXIT
+    current="$(list_img_files "$1" | grep -nF "$1")"
+    if [ "$videos" = true ]; then
+        list_vid_files "$1"
+    fi
+    [ "$thumbnails" = true ] && nsxiv_args="-t"
+    if [ -n "$current" ]; then
+        nsxiv "$nsxiv_args" -i -n "${current%%:*}" -o -- <"$valid_files_tmp"
+    else
+        # fallback incase file didn't have a valid extension, or we couldn't
+        # find it inside the list
+        nsxiv -o -i -- <"$valid_files_tmp"
+    fi
+}
+
+maxdepth=1
+while getopts "mrt?h" opt; do
+    case "$opt" in
+    r)
+        maxdepth=100
+        ;;
+    m)
+        videos=true
+        ;;
+    t)
+        thumbnails=true
+        ;;
+    h | \? | *)
+        show_help
+        exit 0
+        ;;
+    esac
+done
+shift $((OPTIND - 1))
+[ "$1" = '--' ] && shift
+case "$1" in
+"")
+    echo "Usage: ${0##*/} PICTURES" >&2
+    exit 1
+    ;;
+/*) open "$1" ;;
+"~"/*) open "$HOME/${1#"~"/}" ;;
+*) open "$PWD/$1" ;;
+esac