nnn/plugins/preview-tui-ext
2021-03-21 00:01:46 +05:30

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#!/usr/bin/env sh
# Description: Terminal based file previewer
#
# Note: This plugin needs a "NNN_FIFO" to work. See man.
#
# Dependencies:
# - Supports 3 independent methods to preview with:
# - tmux (>=3.0), or
# - kitty with allow_remote_control on, or
# - $TERMINAL set to a terminal (it's xterm by default).
# - less or $PAGER
# - tree or exa or ls
# - mediainfo or file
# - mktemp
# - unzip
# - tar
# - man
# - optional: bsdtar or atool for additional archive preview
# - optional: bat for code syntax highlighting
# - optional: ueberzug, kitty terminal, viu or catimg for images.
# - optional: convert(ImageMagick) for playing gif preview
# - optional: ffmpegthumbnailer for video thumbnails (https://github.com/dirkvdb/ffmpegthumbnailer).
# - optional: ffmpeg for audio thumbnails
# - optional: libreoffce for opendocument/officedocument preview
# - optional: pdftoppm(poppler) for pdf thumbnails
# - optional: gnome-epub-thumbnailer for epub thumbnails (https://gitlab.gnome.org/GNOME/gnome-epub-thumbnailer)
# - optional: fontpreview for font preview (https://github.com/sdushantha/fontpreview)
# - optional: glow or lowdown for markdown
# - optional: w3m or lynx or elinks for html
# - optional: scope.sh file viewer from ranger.
# To use:
# 1. drop scope.sh executable in $PATH
# 2. set/export $USE_SCOPE as 1
# - optional: pistol file viewer (https://github.com/doronbehar/pistol).
# To use:
# 1. install pistol
# 2. set/export $USE_PISTOL as 1
#
# Usage:
# You need to set a NNN_FIFO path and a key for the plugin with NNN_PLUG,
# then start `nnn`:
#
# $ nnn -a
#
# or
#
# $ NNN_FIFO=/tmp/nnn.fifo nnn
#
# Then in `nnn`, launch the `preview-tui` plugin.
#
# If you provide the same NNN_FIFO to all nnn instances, there will be a
# single common preview window. If you provide different FIFO path (e.g.
# with -a), they will be independent.
#
# The previews will be shown in a tmux split. If that isn't possible, it
# will try to use a kitty terminal split. And as a final fallback, a
# different terminal window will be used ($TERMINAL).
#
# Tmux and kitty users can configure $SPLIT to either "h" or "v" to set a
# 'h'orizontal split or a 'v'ertical split (as in, the line that splits the
# windows will be horizontal or vertical).
#
# Kitty users need `allow_remote_control` set to `yes`. To customize the
# window split, `enabled_layouts` has to be set to `all` or `splits` (the
# former is the default value). This terminal is also able to show images
# without extra dependencies.
#
# Shell: POSIX compliant
# Authors: Todd Yamakawa, Léo Villeveygoux, @Recidiviste, Mario Ortiz Manero, Luuk van Baal
SPLIT="$SPLIT" # you can set a permanent split here
TERMINAL="$TERMINAL" # same goes for the terminal
USE_SCOPE="${USE_SCOPE:-0}"
USE_PISTOL="${USE_PISTOL:-0}"
PAGER="${PAGER:-less -P?n -R}"
ARCHIVES="$(echo "$NNN_ARCHIVE" | sed 's/.*(\(.*\)).*/\1/;s/|/ /g')"
TMPDIR="${TMPDIR:-/tmp}"
NUMPREVIEWTUI="$(($(find "$TMPDIR" -maxdepth 1 -name 'nnn-preview-tui-pagerpid*' 2>/dev/null | wc -l) + 1))"
PAGERPID="$TMPDIR/nnn-preview-tui-pagerpid.$NUMPREVIEWTUI"
GIFPID="$TMPDIR/nnn-preview-tui-gifpid.$NUMPREVIEWTUI"
FIFO_UEBERZUG="$TMPDIR/nnn-preview-tui-ueberzug-fifo.$NUMPREVIEWTUI"
[ "$PAGER" = "most" ] && PAGER="less -R"
if [ -e "${TMUX%%,*}" ] && tmux -V | grep -q '[ -][3456789]\.'; then
TERMINAL=tmux
elif [ -n "$KITTY_WINDOW_ID" ] && kitty @ ls >/dev/null 2>&1; then
TERMINAL=kitty
else
TERMINAL="${TERMINAL:-xterm}"
fi
if [ -z "$SPLIT" ] && [ $(($(tput lines) * 2)) -gt "$(tput cols)" ]; then
SPLIT='h'
elif [ "$SPLIT" != 'h' ]; then
SPLIT='v'
fi
exists() {
which "$1" >/dev/null 2>&1
}
fifo_pager() {
cmd="$1"
shift
# We use a FIFO to access $PAGER PID in jobs control
tmpfifopath="$TMPDIR/nnn-preview-tui-fifo.$$"
mkfifo "$tmpfifopath" || return
$PAGER < "$tmpfifopath" &
echo "$!" > "$PAGERPID"
(
exec > "$tmpfifopath"
"$cmd" "$@" &
)
rm "$tmpfifopath"
}
# Binary file: show file info inside the pager
print_bin_info() {
printf -- "-------- \033[1;31mBinary file\033[0m --------\n"
if exists mediainfo; then
mediainfo "$1" 2>/dev/null
else
file -b "$1"
fi
}
preview_file () {
clear
# Trying to use pistol if it's available.
if [ "$USE_PISTOL" -ne 0 ] && exists pistol; then
fifo_pager pistol "$1"
return
fi
# Trying to use scope.sh if it's available.
if [ "$USE_SCOPE" -ne 0 ] && exists scope.sh; then
fifo_pager scope.sh "$1" "$cols" "$lines" "$(mktemp -d)" \
"True" 2>/dev/null
return
fi
# Detecting the exact type of the file: the encoding, mime type, and
# extension in lowercase.
encoding="$(file -Lb --mime-encoding -- "$1")"
mimetype="$(file -Lb --mime-type -- "$1")"
ext="${1##*.}"
if [ -n "$ext" ]; then
ext="$(printf "%s" "${ext}" | tr '[:upper:]' '[:lower:]')"
fi
lines=$(($(tput lines)-1))
cols=$(tput cols)
# Otherwise, falling back to the defaults.
if [ -d "$1" ]; then
cd "$1" || return
if exists tree; then
fifo_pager tree -L 1 --dirsfirst -F -C
elif exists exa; then
fifo_pager exa -G --colour=always 2>/dev/null
else
fifo_pager ls --color=always
fi
elif [ "$encoding" = "binary" ]; then
if [ "$ext" = "gif" ]; then
generate_preview "$cols" "$lines" "$1" "gif"
elif [ "${mimetype%%/*}" = "image" ]; then
image_preview "$cols" "$lines" "$1"
elif [ "${mimetype%%/*}" = "audio" ] && exists ffmpeg; then
generate_preview "$cols" "$lines" "$1" "audio"
elif [ "${mimetype%%/*}" = "video" ] && exists ffmpegthumbnailer; then
generate_preview "$cols" "$lines" "$1" "video"
elif [ "$ext" = "pdf" ] && exists pdftoppm; then
generate_preview "$cols" "$lines" "$1" "pdf"
elif [ "$ext" = "epub" ] && exists gnome-epub-thumbnailer; then
generate_preview "$cols" "$lines" "$1" "epub"
elif [ "${mimetype%%/*}" = "font" ] && exists fontpreview; then
generate_preview "$cols" "$lines" "$1" "font"
elif [ "${mimetype#*office}" != "$mimetype" ] || [ "${mimetype#*document}" != "$mimetype" ] && exists libreoffice; then
generate_preview "$cols" "$lines" "$1" "office"
elif [ "${ARCHIVES#*$ext}" != "$ARCHIVES" ]; then
if exists bsdtar; then
fifo_pager bsdtar -tvf "$1"
elif exists atool; then
fifo_pager atool -l "$1"
fi
elif [ "$mimetype" = "application/zip" ]; then
fifo_pager unzip -l "$1"
elif [ "$ext" = "gz" ] || [ "$ext" = "bz2" ]; then
fifo_pager tar -tvf "$1"
else
fifo_pager print_bin_info "$1"
fi
elif [ "$ext" = "md" ]; then
if exists glow; then
fifo_pager glow -s dark "$1"
elif exists lowdown; then
lowdown -Tterm "$1"
fi
elif [ "$ext" = "htm" ] || [ "$ext" = "html" ] || [ "$ext" = "xhtml" ]; then
if exists w3m; then
fifo_pager w3m "$1"
elif exists lynx; then
fifo_pager lynx "$1"
elif exists elinks; then
fifo_pager elinks "$1"
fi
elif [ "$mimetype" = "text/troff" ]; then
fifo_pager man -Pcat -l "$1"
else
if exists bat; then
fifo_pager bat --terminal-width="$cols" --paging=never --decorations=always --color=always \
"$1" 2>/dev/null
else
$PAGER "$1" &
fi
fi
}
generate_preview() {
if [ ! -f "$TMPDIR/$3.png" ]; then
mkdir -p "$TMPDIR/${3%/*}"
case $4 in
audio) ffmpeg -i "$3" "$TMPDIR/$3.png" -y >/dev/null 2>&1 ;;
epub) gnome-epub-thumbnailer "$3" "$TMPDIR/$3.png" >/dev/null 2>&1 ;;
font) fontpreview -i "$3" -o "$TMPDIR/$3.png" >/dev/null 2>&1 ;;
gif) if exists ueberzug || [ "$TERMINAL" = "kitty" ]; then
if [ ! -d "$TMPDIR/$3" ]; then
mkdir -p "$TMPDIR/$3"
convert -coalesce "$3" "$TMPDIR/$3/${3##*/}.png"
fi
while true; do
for frame in $(find "$TMPDIR/$3"/*.png | sort -V); do
image_preview "$1" "$2" "$frame"
sleep 0.1
done
[ "$LOOP_GIFS" -eq 0 ] && return
done &
echo "$!" > "$GIFPID"
return
else
image_preview "$1" "$2" "$3"
return
fi ;;
office) libreoffice --convert-to png "$3" --outdir "$TMPDIR/${3%/*}" > /dev/null 2>&1
filename="$(echo "${3##*/}" | cut -d. -f1)"
mv "$TMPDIR/${3%/*}/$filename.png" "$TMPDIR/$3.png" ;;
pdf) pdftoppm -png -f 1 -singlefile "$3" "$TMPDIR/$3" >/dev/null 2>&1 ;;
video) ffmpegthumbnailer -i "$3" -o "$TMPDIR/$3.png" -s 0 -q 10 >/dev/null 2>&1 ;;
esac
fi
image_preview "$1" "$2" "$TMPDIR/$3.png"
}
image_preview() {
clear
if [ "$TERMINAL" = "kitty" ]; then
# Kitty terminal users can use the native image preview method.
kitty +kitten icat --silent --place "$1"x"$2"@0x0 --transfer-mode=stream --stdin=no \
"$3"
elif exists ueberzug; then
ueberzug_layer "$1" "$2" "$3"
elif exists catimg; then
catimg "$3" &
echo "$!" > "$GIFPID"
elif exists viu; then
viu -t "$3" &
echo "$!" > "$GIFPID"
else
fifo_pager print_bin_info "$1"
fi
}
ueberzug_layer() {
printf '{"action": "add", "identifier": "nnn_ueberzug", "x": 0, "y": 0, "width": "%s", "height": "%s", "path": "%s"}\n' "$1" "$2" "$3" > "$FIFO_UEBERZUG"
}
ueberzug_remove() {
printf '{"action": "remove", "identifier": "nnn_ueberzug"}\n' > "$FIFO_UEBERZUG"
}
ueberzug_refresh() {
clear
pkill -P "$$" >/dev/null 2>&1
pkill -f -n preview-tui-ext >/dev/null 2>&1
echo > "$NNN_FIFO"
tail --follow "$FIFO_UEBERZUG" | ueberzug layer --silent --parser json &
preview_fifo &
wait
}
if [ "$TERMINAL" != "kitty" ] && [ "$PREVIEW_MODE" ] && exists ueberzug; then
trap 'ueberzug_refresh' WINCH
trap 'rm "$FIFO_UEBERZUG" "$PAGERPID" "$GIFPID"' INT HUP EXIT
fi
preview_fifo() {
# use cat instead of 'exec <' to avoid issues with dash shell
# shellcheck disable=SC2002
cat "$NNN_FIFO" |\
while read -r selection ; do
kill "$(cat "$GIFPID" 2>/dev/null)" >/dev/null 2>&1
kill "$(cat "$PAGERPID" 2>/dev/null)" >/dev/null 2>&1
[ "$TERMINAL" != "kitty" ] && exists ueberzug && ueberzug_remove
preview_file "$selection"
done
[ "$TERMINAL" != "kitty" ] && exists ueberzug && rm "$FIFO_UEBERZUG"
rm "$PAGERPID" "$GIFPID" >/dev/null 2>&1
}
if [ "$PREVIEW_MODE" ]; then
if [ ! -r "$NNN_FIFO" ]; then
echo "No FIFO available! (\$NNN_FIFO='$NNN_FIFO')" >&2
read -r
exit 1
fi
if [ "$TERMINAL" != "kitty" ] && exists ueberzug; then
mkfifo "$FIFO_UEBERZUG"
tail --follow "$FIFO_UEBERZUG" | ueberzug layer --silent --parser json &
fi
preview_file "$1"
preview_fifo &
wait
# Restoring the previous layout for kitty users. This will only work for
# kitty >= 0.18.0.
if [ "$TERMINAL" = "kitty" ]; then
kitty @ last-used-layout --no-response >/dev/null 2>&1
fi
exit 0
fi
if [ "$TERMINAL" = "tmux" ]; then
# tmux splits are inverted
if [ "$SPLIT" = "v" ]; then SPLIT="h"; else SPLIT="v"; fi
tmux split-window -e "NNN_FIFO=$NNN_FIFO" -e "PREVIEW_MODE=1" -d"$SPLIT" "$0" "$1"
elif [ "$TERMINAL" = "kitty" ]; then
# Setting the layout for the new window. It will be restored after the
# script ends.
kitty @ goto-layout splits >/dev/null
# Trying to use kitty's integrated window management as the split window.
# All environmental variables that will be used in the new window must
# be explicitly passed.
kitty @ launch --no-response --title "nnn preview" --keep-focus \
--cwd "$PWD" --env "PATH=$PATH" --env "NNN_FIFO=$NNN_FIFO" \
--env "PREVIEW_MODE=1" --env "PAGER=$PAGER" \
--env "USE_SCOPE=$USE_SCOPE" --env "SPLIT=$SPLIT" \
--env "USE_PISTOL=$USE_PISTOL" \
--location "${SPLIT}split" "$0" "$1" >/dev/null
else
PREVIEW_MODE=1 $TERMINAL -e "$0" "$1" &
fi