X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=driver%2Fsubprocs.c;h=256934b891ce8d5dea5f1341cdc013f89e5c73b9;hb=14463b6ad1ab1ccf81f9c33350b048e410ba94cb;hp=3f43139860243883555f9a910c20f7155c579010;hpb=2a991a811de4c7b22f812682b267b616a809fd9a;p=xscreensaver

diff --git a/driver/subprocs.c b/driver/subprocs.c
index 3f431398..256934b8 100644
--- a/driver/subprocs.c
+++ b/driver/subprocs.c
@@ -71,9 +71,6 @@ extern int kill (pid_t, int);		/* signal() is in sys/signal.h... */
 
 extern saver_info *global_si_kludge;	/* I hate C so much... */
 
-static void hack_subproc_environment (saver_screen_info *ssi);
-
-
 static void
 nice_subproc (int nice_level)
 {
@@ -172,9 +169,49 @@ exec_complex_command (const char *shell, const char *command)
 {
   char *av[5];
   int ac = 0;
-  char *command2 = (char *) malloc (strlen (command) + 6);
-  memcpy (command2, "exec ", 5);
-  memcpy (command2 + 5, command, strlen (command) + 1);
+  char *command2 = (char *) malloc (strlen (command) + 10);
+  const char *s;
+  int got_eq = 0;
+  const char *after_vars;
+
+  /* Skip leading whitespace.
+   */
+  while (*command == ' ' || *command == '\t')
+    command++;
+
+  /* If the string has a series of tokens with "=" in them at them, set
+     `after_vars' to point into the string after those tokens and any
+     trailing whitespace.  Otherwise, after_vars == command.
+   */
+  after_vars = command;
+  for (s = command; *s; s++)
+    {
+      if (*s == '=') got_eq = 1;
+      else if (*s == ' ')
+        {
+          if (got_eq)
+            {
+              while (*s == ' ' || *s == '\t')
+                s++;
+              after_vars = s;
+              got_eq = 0;
+            }
+          else
+            break;
+        }
+    }
+
+  *command2 = 0;
+  strncat (command2, command, after_vars - command);
+  strcat (command2, "exec ");
+  strcat (command2, after_vars);
+
+  /* We have now done these transformations:
+     "foo -x -y"               ==>  "exec foo -x -y"
+     "BLAT=foop      foo -x"   ==>  "BLAT=foop      exec foo -x"
+     "BLAT=foop A=b  foo -x"   ==>  "BLAT=foop A=b  exec foo -x"
+   */
+
 
   /* Invoke the shell as "/bin/sh -c 'exec prog -arg -arg ...'" */
   av [ac++] = (char *) shell;
@@ -248,7 +285,19 @@ exec_screenhack (saver_info *si, const char *command)
   saver_preferences *p = &si->prefs;
 
 #ifndef VMS
-  Bool hairy_p = !!strpbrk (command, "*?$&!<>[];`'\\\"");
+  Bool hairy_p = !!strpbrk (command, "*?$&!<>[];`'\\\"=");
+  /* note: = is in the above because of the sh syntax "FOO=bar cmd". */
+
+  if (getuid() == (uid_t) 0 || geteuid() == (uid_t) 0)
+    {
+      /* If you're thinking of commenting this out, think again.
+         If you do so, you will open a security hole.  Mail jwz
+         so that he may enlighten you as to the error of your ways.
+       */
+      fprintf (stderr, "%s: we're still running as root!  Disaster!\n",
+               blurb());
+      saver_exit (si, 1, 0);
+    }
 
   if (p->verbose_p)
     fprintf (stderr, "%s: spawning \"%s\" in pid %lu%s.\n",
@@ -325,20 +374,27 @@ make_job (pid_t pid, const char *cmd)
   static char name [1024];
   const char *in = cmd;
   char *out = name;
+  int got_eq = 0;
+  int first = 1;
 
   clean_job_list();
 
+ AGAIN:
   while (isspace(*in)) in++;		/* skip whitespace */
-  while (!isspace(*in) && *in != ':')
+  while (!isspace(*in) && *in != ':') {
+    if (*in == '=') got_eq = 1;
     *out++ = *in++;			/* snarf first token */
-  while (isspace(*in)) in++;		/* skip whitespace */
-  if (*in == ':')			/* token was a visual name; skip it. */
-    {
-      in++;
+  }
+
+  if (got_eq)				/* if the first token was FOO=bar */
+    {					/* then get the next token instead. */
+      got_eq = 0;
       out = name;
-      while (isspace(*in)) in++;		/* skip whitespace */
-      while (!isspace(*in)) *out++ = *in++;	/* snarf first token */
+      first = 0;
+      goto AGAIN;
     }
+
+  while (isspace(*in)) in++;		/* skip whitespace */
   *out = 0;
 
   job->name = strdup(name);
@@ -703,35 +759,25 @@ init_sigchld (void)
 
 
 static Bool
-select_visual_of_hack (saver_screen_info *ssi, const char *hack)
+select_visual_of_hack (saver_screen_info *ssi, screenhack *hack)
 {
   saver_info *si = ssi->global;
   saver_preferences *p = &si->prefs;
   Bool selected;
-  static char vis [1024];
-  const char *in = hack;
-  char *out = vis;
-  while (isspace(*in)) in++;		/* skip whitespace */
-  while (!isspace(*in) && *in != ':')
-    *out++ = *in++;			/* snarf first token */
-  while (isspace(*in)) in++;		/* skip whitespace */
-  *out = 0;
 
-  if (*in == ':')
-    selected = select_visual(ssi, vis);
+  if (hack->visual && *hack->visual)
+    selected = select_visual(ssi, hack->visual);
   else
     selected = select_visual(ssi, 0);
 
-  if (!selected && (p->verbose_p || si->demo_mode_p))
-    {
-      if (*in == ':') in++;
-      while (isspace(*in)) in++;
-      fprintf (stderr,
-	       (si->demo_mode_p
-		? "%s: warning, no \"%s\" visual for \"%s\".\n"
-		: "%s: no \"%s\" visual; skipping \"%s\".\n"),
-	       blurb(), (vis ? vis : "???"), in);
-    }
+  if (!selected && (p->verbose_p || si->demoing_p))
+    fprintf (stderr,
+             (si->demoing_p
+              ? "%s: warning, no \"%s\" visual for \"%s\".\n"
+              : "%s: no \"%s\" visual; skipping \"%s\".\n"),
+             blurb(),
+             (hack->visual && *hack->visual ? hack->visual : "???"),
+             hack->command);
 
   return selected;
 }
@@ -745,81 +791,82 @@ spawn_screenhack_1 (saver_screen_info *ssi, Bool first_time_p)
   raise_window (si, first_time_p, True, False);
   XFlush (si->dpy);
 
-  if (p->screenhacks_count || si->demo_mode_p)
+  if (p->screenhacks_count)
     {
-      char *hack;
+      screenhack *hack;
       pid_t forked;
       char buf [255];
       int new_hack;
+      int retry_count = 0;
+      Bool force = False;
 
-      if (si->demo_mode_p)
-	{
-	  hack = si->demo_hack;
+    AGAIN:
 
-	  /* Ignore visual-selection failure if in demo mode. */
-	  (void) select_visual_of_hack (ssi, hack);
+      if (p->screenhacks_count == 1)
+	/* If there is only one hack in the list, there is no choice. */
+	new_hack = 0;
+
+      else if (si->selection_mode == -1)
+	/* Select the next hack, wrapping. */
+	new_hack = (ssi->current_hack + 1) % p->screenhacks_count;
+
+      else if (si->selection_mode == -2)
+	/* Select the previous hack, wrapping. */
+	new_hack = ((ssi->current_hack + p->screenhacks_count - 1)
+		    % p->screenhacks_count);
+
+      else if (si->selection_mode > 0)
+	/* Select a specific hack, by number.  No negotiation. */
+	{
+	  new_hack = ((si->selection_mode - 1) % p->screenhacks_count);
+	  force = True;
 	}
       else
 	{
-	  int retry_count = 0;
-
-	AGAIN:
-	  if (p->screenhacks_count == 1)
-	    new_hack = 0;
-	  else if (si->selection_mode == -1)
-	    new_hack = (ssi->current_hack + 1) % p->screenhacks_count;
-	  else if (si->selection_mode == -2)
-	    new_hack = ((ssi->current_hack + p->screenhacks_count - 1)
-			% p->screenhacks_count);
-	  else if (si->selection_mode > 0)
-	    new_hack = ((si->selection_mode - 1) % p->screenhacks_count);
-	  else
-	    while ((new_hack = random () % p->screenhacks_count)
-		   == ssi->current_hack)
-	      ;
-	  ssi->current_hack = new_hack;
-	  hack = p->screenhacks[ssi->current_hack];
+	  /* Select a random hack (but not the one we just ran.) */
+	  while ((new_hack = random () % p->screenhacks_count)
+		 == ssi->current_hack)
+	    ;
+	}
 
-	  if (!select_visual_of_hack (ssi, hack))
+      ssi->current_hack = new_hack;
+      hack = p->screenhacks[ssi->current_hack];
+
+      /* If the hack is disabled, or there is no visual for this hack,
+	 then try again (move forward, or backward, or re-randomize.)
+	 Unless this hack was specified explicitly, in which case,
+	 use it regardless.
+       */
+      if (force)
+        select_visual_of_hack (ssi, hack);
+        
+      if (!force &&
+	  (!hack->enabled_p ||
+	   !select_visual_of_hack (ssi, hack)))
+	{
+	  if (++retry_count > (p->screenhacks_count*4))
 	    {
-	      if (++retry_count > (p->screenhacks_count*4))
-		{
-		  /* Uh, oops.  Odds are, there are no suitable visuals,
-		     and we're looping.  Give up.  (This is totally lame,
-		     what we should do is make a list of suitable hacks at
-		     the beginning, then only loop over them.)
-		  */
-		  if (p->verbose_p)
-		    fprintf(stderr,
-			    "%s: no suitable visuals for these programs.\n",
-			    blurb());
-		  return;
-		}
-	      else
-		goto AGAIN;
+	      /* Uh, oops.  Odds are, there are no suitable visuals,
+		 and we're looping.  Give up.  (This is totally lame,
+		 what we should do is make a list of suitable hacks at
+		 the beginning, then only loop over them.)
+	      */
+	      if (p->verbose_p)
+		fprintf(stderr,
+			"%s: no suitable visuals for these programs.\n",
+			blurb());
+	      return;
 	    }
+	  else
+	    goto AGAIN;
 	}
 
+      /* Turn off "next" and "prev" modes now, but "demo" mode is only
+	 turned off by explicit action.
+       */
       if (si->selection_mode < 0)
 	si->selection_mode = 0;
 
-
-      /* If there's a visual description on the front of the command, nuke it.
-       */
-      {
-	char *in = hack;
-	while (isspace(*in)) in++;			/* skip whitespace */
-	hack = in;
-	while (!isspace(*in) && *in != ':') in++;	/* snarf first token */
-	while (isspace(*in)) in++;			/* skip whitespace */
-	if (*in == ':')
-	  {
-	    in++;
-	    while (isspace(*in)) in++;
-	    hack = in;
-	  }
-      }
-
       switch ((int) (forked = fork ()))
 	{
 	case -1:
@@ -832,13 +879,13 @@ spawn_screenhack_1 (saver_screen_info *ssi, Bool first_time_p)
 	  close (ConnectionNumber (si->dpy));	/* close display fd */
 	  nice_subproc (p->nice_inferior);	/* change process priority */
 	  hack_subproc_environment (ssi);	/* set $DISPLAY */
-	  exec_screenhack (si, hack);		/* this does not return */
+	  exec_screenhack (si, hack->command);	/* this does not return */
 	  abort();
 	  break;
 
 	default:
 	  ssi->pid = forked;
-	  (void) make_job (forked, hack);
+	  (void) make_job (forked, hack->command);
 	  break;
 	}
     }
@@ -848,22 +895,21 @@ spawn_screenhack_1 (saver_screen_info *ssi, Bool first_time_p)
 void
 spawn_screenhack (saver_info *si, Bool first_time_p)
 {
-  int i;
-
-  if (!monitor_powered_on_p (si))
+  if (monitor_powered_on_p (si))
     {
-      if (si->prefs.verbose_p)
-	fprintf (stderr,
-		 "%s: server reports that monitor has powered down; "
-		 "not launching a new hack.\n", blurb());
-      return;
+      int i;
+      for (i = 0; i < si->nscreens; i++)
+        {
+          saver_screen_info *ssi = &si->screens[i];
+          spawn_screenhack_1 (ssi, first_time_p);
+        }
     }
+  else if (si->prefs.verbose_p)
+    fprintf (stderr,
+             "%s: server reports that monitor has powered down; "
+             "not launching a new hack.\n", blurb());
 
-  for (i = 0; i < si->nscreens; i++)
-    {
-      saver_screen_info *ssi = &si->screens[i];
-      spawn_screenhack_1 (ssi, first_time_p);
-    }
+  store_saver_status (si);  /* store current hack numbers */
 }
 
 
@@ -958,7 +1004,7 @@ hack_environment (saver_info *si)
 }
 
 
-static void
+void
 hack_subproc_environment (saver_screen_info *ssi)
 {
   /* Store $DISPLAY into the environment, so that the $DISPLAY variable that
@@ -1007,7 +1053,6 @@ static char **saved_argv;
 void
 save_argv (int argc, char **argv)
 {
-  /* Leave room for one more argument, the -initial-demo-mode switch. */
   saved_argv = (char **) calloc (argc+2, sizeof (char *));
   saved_argv [argc] = 0;
   while (argc--)
@@ -1018,45 +1063,24 @@ save_argv (int argc, char **argv)
     }
 }
 
-/* Modifies saved_argv to either contain or not contain "-initial-demo-mode".
+
+/* Re-execs the process with the arguments in saved_argv.
+   Does not return unless there was an error.
  */
-static void
-hack_saved_argv (Bool demo_mode_p)
+void
+restart_process (saver_info *si)
 {
-  static char *demo_mode_switch = "-initial-demo-mode";
-
-  if (demo_mode_p)		/* We want the switch to be in the args. */
-    {
-      /* See if the switch is there already.  If so, we're done. */
-      int i;
-      for (i = 0; saved_argv[i]; i++)
-	if (!strcmp (saved_argv[i], demo_mode_switch))
-	  return;
-
-      /* If it wasn't there, add it to the end.  save_argv() made room. */
-      saved_argv [i] = demo_mode_switch;
-      saved_argv [i+1] = 0;
-    }
-  else				/* We want the switch to not be in the args. */
+  if (si->prefs.verbose_p)
     {
       int i;
+      fprintf (real_stderr, "%s: re-executing", blurb());
       for (i = 0; saved_argv[i]; i++)
-	while (!strcmp (saved_argv [i], demo_mode_switch))
-	  {
-	    int j;
-	    for (j = i; saved_argv[j]; j++)
-	      saved_argv [j] = saved_argv [j+1];
-	  }
+	fprintf (real_stderr, " %s", saved_argv[i]);
+      fprintf (real_stderr, "\n");
     }
-}
+  describe_uids (si, real_stderr);
+  fprintf (real_stderr, "\n");
 
-
-/* Re-execs the process with the arguments in saved_argv.
-   Does not return unless there was an error.
- */
-static void
-restart_process_1 (saver_info *si)
-{
   fflush (real_stdout);
   fflush (real_stderr);
   execvp (saved_argv [0], saved_argv);	/* shouldn't return */
@@ -1068,26 +1092,3 @@ restart_process_1 (saver_info *si)
   }
   XBell(si->dpy, 0);
 }
-
-
-/* Re-execs the process with the arguments in saved_argv,
-   minus -initial-demo-mode.
-   Does not return unless there was an error.
- */
-void
-restart_process (saver_info *si)
-{
-  hack_saved_argv (True);
-  restart_process_1 (si);
-}
-
-/* Re-execs the process with the arguments in saved_argv,
-   plus -initial-demo-mode.
-   Does not return unless there was an error.
- */
-void
-demo_mode_restart_process (saver_info *si)
-{
-  hack_saved_argv (False);
-  restart_process_1 (si);
-}