preview-tui: error to foreground (#970)

* preview-tui: error to foreground

* preview-tui: test KITTY_LISTEN_ON

plugins/preview-tui

@@ -8,7 +8,7 @@
 # Dependencies:
 #    - Supports 4 independent methods to preview with:
 #        - tmux (>=3.0), or
-#        - kitty with allow_remote_control on, or
+#        - kitty with allow_remote_control and listen_on set in kitty.conf, or
 #        - QuickLook on WSL (https://github.com/QL-Win/QuickLook)
 #        - $TERMINAL set to a terminal (it's xterm by default).
 #    - less or $PAGER
@@ -79,7 +79,7 @@ startpreview() {
 
     if [ -e "${TMUX%%,*}" ] && tmux -V | grep -q '[ -][3456789]\.'; then
         TERMINAL=tmux
-    elif [ -n "$KITTY_WINDOW_ID" ] && kitty @ ls >/dev/null 2>&1; then
+    elif [ -n "$KITTY_LISTEN_ON" ]; then
         TERMINAL=kitty
     else
         TERMINAL="${TERMINAL:-xterm}"
@@ -240,10 +240,10 @@ image_preview() {
         ueberzug_layer "$1" "$2" "$3"
     elif exists catimg; then
         catimg "$3" &
-        echo "$!" > "$GIFPID"
+        printf "%s" "$!" > "$GIFPID"
     elif exists viu; then
         viu -t "$3" &
-        echo "$!" > "$GIFPID"
+        printf "%s" "$!" > "$GIFPID"
     else
         fifo_pager print_bin_info "$3"
     fi
@@ -264,7 +264,7 @@ ueberzug_refresh() {
     pkill -f -n preview-tui-ext >/dev/null 2>&1
     tail --follow "$FIFO_UEBERZUG" | ueberzug layer --silent --parser json &
     preview_file "$(cat "$CURSEL")"
-    echo > "$NNN_FIFO"
+    printf "\n" > "$NNN_FIFO"
     preview_fifo 2>/dev/null &
     wait
 }
@@ -278,7 +278,7 @@ preview_fifo() {
         kill "$(cat "$PAGERPID" 2>/dev/null)" >/dev/null 2>&1
         [ "$TERMINAL" != "kitty" ] && exists ueberzug && ueberzug_remove
         preview_file "$selection"
-        echo "$selection" > "$CURSEL"
+        printf "%s" "$selection" > "$CURSEL"
     done
     [ "$TERMINAL" != "kitty" ] && exists ueberzug && rm "$FIFO_UEBERZUG"
     rm "$PAGERPID" "$GIFPID" "$CURSEL" >/dev/null 2>&1
@@ -286,12 +286,6 @@ preview_fifo() {
 }
 
 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"
         trap 'ueberzug_refresh; rm $FIFO_UEBERZUG' WINCH
@@ -302,6 +296,18 @@ if [ "$PREVIEW_MODE" ]; then
     preview_file "$1"
     preview_fifo 2>/dev/null &
     wait
-fi
+else
-
+    if [ ! -r "$NNN_FIFO" ]; then
+        clear
+        printf "No FIFO available! (\$NNN_FIFO='%s')\nPlease read the documentation" "$NNN_FIFO"
+        read -r _
+    elif [ "$KITTY_WINDOW_ID" ] && [ -z "$KITTY_LISTEN_ON" ]; then
+        # The escape codes used to control kitty splits cause problems when run from a background process.
+        # Use --listen-on flag or listen_on config variable to avoid(https://sw.kovidgoyal.net/kitty/conf.html)
+        clear
+        printf "\$KITTY_LISTEN_ON not set!\nPlease add listen_on to your kitty.conf or start with the --listen-on flag."
+        read -r _
+    else
         togglepreview "$1" &
+    fi
+fi

plugins/preview-tui-ext

@@ -7,7 +7,7 @@
 # Dependencies:
 #    - Supports 4 independent methods to preview with:
 #        - tmux (>=3.0), or
-#        - kitty with allow_remote_control on, or
+#        - kitty with allow_remote_control and listen_on set in kitty.conf, or
 #        - QuickLook on WSL (https://github.com/QL-Win/QuickLook)
 #        - $TERMINAL set to a terminal (it's xterm by default).
 #    - less or $PAGER
@@ -71,6 +71,7 @@
 #
 # Shell: POSIX compliant
 # Authors: Todd Yamakawa, Léo Villeveygoux, @Recidiviste, Mario Ortiz Manero, Luuk van Baal
+
 SPLIT="$SPLIT"  # you can set a permanent split here
 TERMINAL="$TERMINAL"  # same goes for the terminal
 USE_SCOPE="${USE_SCOPE:-0}"
@@ -94,7 +95,7 @@ startpreview() {
 
     if [ -e "${TMUX%%,*}" ] && tmux -V | grep -q '[ -][3456789]\.'; then
         TERMINAL=tmux
-    elif [ -n "$KITTY_WINDOW_ID" ] && kitty @ ls >/dev/null 2>&1; then
+    elif [ -n "$KITTY_LISTEN_ON" ]; then
         TERMINAL=kitty
     else
         TERMINAL="${TERMINAL:-xterm}"
@@ -169,7 +170,7 @@ fifo_pager() {
     mkfifo "$tmpfifopath" || return
 
     $PAGER < "$tmpfifopath" &
-    echo "$!" > "$PAGERPID"
+    printf "%s" "$!" > "$PAGERPID"
 
     (
         exec > "$tmpfifopath"
@@ -316,7 +317,7 @@ generate_preview() {
                             done
                             [ "$LOOP_GIFS" -eq 0 ] && return
                         done &
-                        echo "$!" > "$GIFPID"
+                        printf "%s" "$!" > "$GIFPID"
                         return
                  else
                     image_preview "$1" "$2" "$3"
@@ -324,7 +325,7 @@ generate_preview() {
                  fi ;;
             image) convert "$3" -flatten -resize "$NNN_PREVIEWWIDTH"x"$NNN_PREVIEWHEIGHT"\> "$NNN_PREVIEWDIR/$3.jpg" ;;
             office) libreoffice --convert-to jpg "$3" --outdir "$NNN_PREVIEWDIR/${3%/*}" > /dev/null 2>&1
-                    filename="$(echo "${3##*/}" | cut -d. -f1)"
+                    filename="$(printf "%s" "${3##*/}" | cut -d. -f1)"
                     mv "$NNN_PREVIEWDIR/${3%/*}/$filename.jpg" "$NNN_PREVIEWDIR/$3.jpg" ;;
             pdf) pdftoppm -jpeg -f 1 -singlefile "$3" "$NNN_PREVIEWDIR/$3" >/dev/null 2>&1 ;;
             video) ffmpegthumbnailer -m -s0 -i "$3" -o "$NNN_PREVIEWDIR/$3.jpg" >/dev/null 2>&1 || rm "$NNN_PREVIEWDIR/$3.jpg" ;;
@@ -346,10 +347,10 @@ image_preview() {
         ueberzug_layer "$1" "$2" "$3"
     elif exists catimg; then
         catimg "$3" &
-        echo "$!" > "$GIFPID"
+        printf "%s" "$!" > "$GIFPID"
     elif exists viu; then
         viu -t "$3" &
-        echo "$!" > "$GIFPID"
+        printf "%s" "$!" > "$GIFPID"
     else
         fifo_pager print_bin_info "$3"
     fi
@@ -370,7 +371,7 @@ ueberzug_refresh() {
     pkill -f -n preview-tui-ext >/dev/null 2>&1
     tail --follow "$FIFO_UEBERZUG" | ueberzug layer --silent --parser json &
     preview_file "$(cat "$CURSEL")"
-    echo > "$NNN_FIFO"
+    printf "\n" > "$NNN_FIFO"
     preview_fifo 2>/dev/null &
     wait
 }
@@ -384,7 +385,7 @@ preview_fifo() {
         kill "$(cat "$PAGERPID" 2>/dev/null)" >/dev/null 2>&1
         [ "$TERMINAL" != "kitty" ] && exists ueberzug && ueberzug_remove
         preview_file "$selection"
-        echo "$selection" > "$CURSEL"
+        printf "%s" "$selection" > "$CURSEL"
     done
     [ "$TERMINAL" != "kitty" ] && exists ueberzug && rm "$FIFO_UEBERZUG"
     rm "$PAGERPID" "$GIFPID" "$CURSEL" >/dev/null 2>&1
@@ -392,12 +393,6 @@ preview_fifo() {
 }
 
 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"
         trap 'ueberzug_refresh; rm $FIFO_UEBERZUG' WINCH
@@ -408,6 +403,18 @@ if [ "$PREVIEW_MODE" ]; then
     preview_file "$1"
     preview_fifo 2>/dev/null &
     wait
-fi
+else
-
+    if [ ! -r "$NNN_FIFO" ]; then
+        clear
+        printf "No FIFO available! (\$NNN_FIFO='%s')\nPlease read the documentation" "$NNN_FIFO"
+        read -r _
+    elif [ "$KITTY_WINDOW_ID" ] && [ -z "$KITTY_LISTEN_ON" ]; then
+        # The escape codes used to control kitty splits cause problems when run from a background process.
+        # Use --listen-on flag or listen_on config variable to avoid(https://sw.kovidgoyal.net/kitty/conf.html)
+        clear
+        printf "\$KITTY_LISTEN_ON not set!\nPlease add listen_on to your kitty.conf or start with the --listen-on flag."
+        read -r _
+    else
         togglepreview "$1" &
+    fi
+fi