http://packetstormsecurity.org/UNIX/admin/xscreensaver-4.01.tar.gz

[xscreensaver] / driver / stderr.c

diff --git a/driver/stderr.c b/driver/stderr.c
index 4258f874c5328319df5d886f934dc4d65d58b249..5f337c0059c059ed147db3ab6a2d575b583bd6d0 100644 (file)
--- a/driver/stderr.c
+++ b/driver/stderr.c
@@ -1,5 +1,5 @@
 /* stderr.c --- capturing stdout/stderr output onto the screensaver window.
- * xscreensaver, Copyright (c) 1991-1998 Jamie Zawinski <jwz@jwz.org>
+ * xscreensaver, Copyright (c) 1991-1998, 2001 Jamie Zawinski <jwz@jwz.org>
  *
  * Permission to use, copy, modify, distribute, and sell this software and its
  * documentation for any purpose is hereby granted without fee, provided that
@@ -47,9 +47,14 @@ static char stderr_buffer [4096];
 static char *stderr_tail = 0;
 static time_t stderr_last_read = 0;
 
+static int stderr_stdout_read_fd = -1;
+
 static void make_stderr_overlay_window (saver_screen_info *);
 
 
+/* Recreates the stderr window or GCs: do this when the xscreensaver window
+   on a screen has been re-created.
+ */
 void
 reset_stderr (saver_screen_info *ssi)
 {
@@ -75,6 +80,10 @@ reset_stderr (saver_screen_info *ssi)
   ssi->stderr_cmap = 0;
 }
 
+/* Erases any stderr text overlaying the screen (if possible) and resets
+   the stderr output cursor to the upper left.  Do this when the xscreensaver
+   window is cleared.
+ */
 void
 clear_stderr (saver_screen_info *ssi)
 {
@@ -86,6 +95,8 @@ clear_stderr (saver_screen_info *ssi)
 }
 
 
+/* Draws the string on the screen's window.
+ */
 static void
 print_stderr_1 (saver_screen_info *ssi, char *string)
 {
@@ -163,15 +174,17 @@ print_stderr_1 (saver_screen_info *ssi, char *string)
              ssi->stderr_text_y = 0;
 #else
              int offset = ssi->stderr_line_height * 5;
+              XWindowAttributes xgwa;
+              XGetWindowAttributes (dpy, window, &xgwa);
+
              XCopyArea (dpy, window, window, ssi->stderr_gc,
                         0, v_border + offset,
-                        WidthOfScreen (screen),
-                        (HeightOfScreen (screen) - v_border - v_border
-                         - offset),
+                        xgwa.width,
+                        (xgwa.height - v_border - v_border - offset),
                         0, v_border);
              XClearArea (dpy, window,
-                         0, HeightOfScreen (screen) - v_border - offset,
-                         WidthOfScreen (screen), offset, False);
+                         0, xgwa.height - v_border - offset,
+                         xgwa.width, offset, False);
              ssi->stderr_text_y -= offset;
 #endif
            }
@@ -202,7 +215,9 @@ make_stderr_overlay_window (saver_screen_info *ssi)
     {
       int depth = visual_depth (ssi->screen, visual);
       XSetWindowAttributes attrs;
+      XWindowAttributes xgwa;
       unsigned long attrmask;
+      XGetWindowAttributes (si->dpy, ssi->screensaver_window, &xgwa);
 
       if (si->prefs.debug_p)
        fprintf(real_stderr,
@@ -224,13 +239,15 @@ make_stderr_overlay_window (saver_screen_info *ssi)
 
       ssi->stderr_overlay_window =
        XCreateWindow(si->dpy, ssi->screensaver_window, 0, 0,
-                     WidthOfScreen(ssi->screen), HeightOfScreen(ssi->screen),
+                     xgwa.width, xgwa.height,
                      0, depth, InputOutput, visual, attrmask, &attrs);
       XMapRaised(si->dpy, ssi->stderr_overlay_window);
     }
 }
 
 
+/* Draws the string on each screen's window as error text.
+ */
 static void
 print_stderr (saver_info *si, char *string)
 {
@@ -246,6 +263,9 @@ print_stderr (saver_info *si, char *string)
 }
 
 
+/* Polls the stderr buffer every few seconds and if it finds any text,
+   writes it on all screens.
+ */
 static void
 stderr_popup_timer_fn (XtPointer closure, XtIntervalId *id)
 {
@@ -268,6 +288,9 @@ stderr_popup_timer_fn (XtPointer closure, XtIntervalId *id)
 }
 
 
+/* Called when data becomes available on the stderr pipe.  Copies it into
+   stderr_buffer where stderr_popup_timer_fn() can find it later.
+ */
 static void
 stderr_callback (XtPointer closure, int *fd, XtIntervalId *id)
 {
@@ -277,6 +300,9 @@ stderr_callback (XtPointer closure, int *fd, XtIntervalId *id)
   int size;
   int read_this_time = 0;
 
+  if (!fd || *fd < 0 || *fd != stderr_stdout_read_fd)
+    abort();
+
   if (stderr_tail == 0)
     stderr_tail = stderr_buffer;
 
@@ -329,6 +355,10 @@ stderr_callback (XtPointer closure, int *fd, XtIntervalId *id)
     }
 }
 
+/* If stderr capturing is desired, this replaces `stdout' and `stderr'
+   with a pipe, so that any output written to them will show up on the
+   screen as well as on the original value of those streams.
+ */
 void
 initialize_stderr (saver_info *si)
 {
@@ -435,6 +465,43 @@ initialize_stderr (saver_info *si)
        }
     }
 
+  stderr_stdout_read_fd = in;
   XtAppAddInput (si->app, in, (XtPointer) XtInputReadMask, stderr_callback,
                 (XtPointer) si);
 }
+
+
+/* If there is anything in the stderr buffer, flush it to the real stderr.
+   This does no X operations.  Call this when exiting to make sure any
+   last words actually show up.
+ */
+void
+shutdown_stderr (saver_info *si)
+{
+  fflush (stdout);
+  fflush (stderr);
+
+  if (!real_stderr || stderr_stdout_read_fd < 0)
+    return;
+
+  stderr_callback ((XtPointer) si, &stderr_stdout_read_fd, 0);
+
+  if (stderr_buffer &&
+      stderr_tail &&
+      stderr_buffer < stderr_tail)
+    {
+      *stderr_tail = 0;
+      fprintf (real_stderr, "%s", stderr_buffer);
+      stderr_tail = stderr_buffer;
+    }
+
+  if (real_stdout) fflush (real_stdout);
+  if (real_stderr) fflush (real_stderr);
+
+  if (stdout != real_stdout)
+    dup2 (fileno(real_stdout), fileno(stdout));
+  if (stderr != real_stderr)
+    dup2 (fileno(real_stderr), fileno(stderr));
+
+  stderr_stdout_read_fd = -1;
+}