emacs-framebuffer

commit e99f1fc059555a07291c6b437f3feb0c39ad404c
parent e75ca19318dcfaef7750b422baa5463125638e7f
Author: Tomas Hlavaty <tom@logand.com>
Date:   Sat, 17 Oct 2020 19:49:02 +0200

more robust w3mimgdisplay invocation

on debian 10:
- the program is not in the path
- W3M_TTY needs to be set

Diffstat:
M
emacs-framebuffer.el
 | 
43
++++++++++++++++++++++++++++++++++++++++++-

1 file changed, 42 insertions(+), 1 deletion(-)
diff --git a/emacs-framebuffer.el b/emacs-framebuffer.el
@@ -25,6 +25,11 @@
 ;;;   (require 'framebuffer)
 ;;;   (framebuffer-install))
 
+(defcustom framebuffer-w3mimgdisplay-program nil
+  "Specify the path to w3mimgdisplay program."
+  :type 'string
+  :group 'framebuffer)
+
 (defcustom framebuffer-width nil
   "Specify the framebuffer width."
   :type 'number
@@ -159,6 +164,26 @@
       (call-process "convert" nil nil nil (expand-file-name file) ofile))
     ofile))
 
+(defun framebuffer-tty-p (filename)
+  (when (string-match "^/dev/tty[0-9]+$" filename)
+    filename))
+
+(defvar framebuffer-tty nil)
+(defun framebuffer-tty ()
+  (or framebuffer-tty
+      (setq framebuffer-tty
+	    (framebuffer-tty-p
+	     (file-chase-links (format "/proc/%d/fd/0" (emacs-pid)))))))
+
+(defun framebuffer-file-exists-p (filename)
+  (when (file-exists-p filename)
+    filename))
+
+(defun framebuffer-w3mimgdisplay-program ()
+  (or framebuffer-w3mimgdisplay-program
+      (framebuffer-file-exists-p "/usr/lib/w3m/w3mimgdisplay") ;; debian10
+      "w3mimgdisplay"))
+
 (defun framebuffer-draw (x y w h sx sy sw sh file)
   (let ((format (framebuffer-file-format file)))
     (case format
@@ -175,7 +200,23 @@
     (insert (format "0;1;%d;%d;%d;%d;%s;%s;%s;%s;%s\n" x y w h
                     (or sx "") (or sy "") (or sw "") (or sh "")
                     (expand-file-name file)))
-    (call-process-region (point-min) (point-max) "w3mimgdisplay")))
+    (let ((z (call-process-region (point-min)
+				  (point-max)
+				  (framebuffer-w3mimgdisplay-program))))
+      (unless (zerop z)
+	(if (getenv "W3M_TTY")
+	    (error "w3mimgdisplay failed with code %d" z)
+	  (let ((tty (framebuffer-tty)))
+	    (cond
+	     (tty
+	      (setenv "W3M_TTY" tty)
+	      (let ((z (call-process-region (point-min)
+					    (point-max)
+					    (framebuffer-w3mimgdisplay-program))))
+		(unless (zerop z)
+		  (error "w3mimgdisplay failed with code %d, try setting W3M_TTY=$(tty)" z))))
+	     (t
+	      (error "w3mimgdisplay failed with code %d, try setting W3M_TTY=$(tty)" z)))))))))
 
 (defun framebuffer-buffer-brook ()
   (lambda ()