* src/main.c: include sys/wait.h

(chld_handler): new function

* src/events.c: include sys/wait.h
(handle_signals): Print an error message in the case of a child
signal.

* src/data.h (struct rp_child_info): New struct.
(child_info): New global.
(chld_signalled): likewise

* src/actions.c (spawn): Let the SIGCHLD handler handle process
completion instead of doing an ugly dance.

4 files changed, 64 insertions, 16 deletions

diff --git a/src/actions.c b/src/actions.c
index 2779101..d02a983 100644
--- a/src/actions.c
+++ b/src/actions.c
@@ -973,29 +973,27 @@ void
 spawn(void *data)
 {
   char *cmd = data;
-  /* Ugly dance to avoid leaving zombies.  Could use SIGCHLD, but it's
-     not very portable. */
-  if (fork() == 0) 
+  int pid;
+
+  pid = fork();
+  if (pid == 0) 
     {
-      if (fork() == 0) 
-	{
-	  /* Some process setup to make sure the spawned process runs
-	     in its own session. */
-	  putenv(current_screen()->display_string);
+      /* Some process setup to make sure the spawned process runs
+	 in its own session. */
+      putenv(current_screen()->display_string);
 #ifdef HAVE_SETSID
-	  setsid();
+      setsid();
 #endif
 #if defined (HAVE_SETPGID)
-	  setpgid (0, 0);
+      setpgid (0, 0);
 #elif defined (HAVE_SETPGRP)
-	  setpgrp (0, 0);
+      setpgrp (0, 0);
 #endif
-	  execl("/bin/sh", "sh", "-c", cmd, 0);
-	  _exit(EXIT_FAILURE);
-	}
-      _exit(EXIT_SUCCESS);
+      execl("/bin/sh", "sh", "-c", cmd, 0);
+      _exit(EXIT_FAILURE);
     }
-  wait((int *) 0);
+
+/*   wait((int *) 0); */
   PRINT_DEBUG ("spawned %s\n", cmd);
 }
 
diff --git a/src/data.h b/src/data.h
index eae7df7..d81918d 100644
--- a/src/data.h
+++ b/src/data.h
@@ -165,6 +165,17 @@ struct rp_defaults
   int warp;
 };
 
+/* Information about a child process. */
+struct rp_child_info
+{
+  int pid;
+  int status;
+};
+
+/* When a child process exits this structure holds the information
+   about it to be used to report back to the user. */
+extern struct rp_child_info child_info;
+
 extern struct rp_defaults defaults;
 
 /* The prefix key also known as the command character under screen. */
@@ -250,6 +261,7 @@ extern struct modifier_info rp_modifier_info;
 extern int alarm_signalled;
 extern int kill_signalled;
 extern int hup_signalled;
+extern int chld_signalled;
 
 /* rudeness levels */
 extern int rp_honour_transient_raise;
diff --git a/src/events.c b/src/events.c
index 4004c61..54270c3 100644
--- a/src/events.c
+++ b/src/events.c
@@ -33,6 +33,7 @@
 #include <errno.h>
 #include <unistd.h>
 #include <sys/time.h>
+#include <sys/wait.h>
 
 #include "ratpoison.h"
 
@@ -782,6 +783,12 @@ handle_signals ()
       alarm_signalled = 0;
     }
 
+  if (chld_signalled > 0)
+    {
+      marked_message_printf (0,0, " Command not found ");
+      chld_signalled = 0;
+    }
+
   if (hup_signalled > 0)
     {
       clean_up (); 
diff --git a/src/main.c b/src/main.c
index d5d5417..4f4e9af 100644
--- a/src/main.c
+++ b/src/main.c
@@ -33,6 +33,7 @@
 #include <unistd.h>
 #include <getopt.h>
 #include <string.h>
+#include <sys/wait.h>
 
 #include "ratpoison.h"
 
@@ -41,6 +42,7 @@ static void init_screen (screen_info *s, int screen_num);
 int alarm_signalled = 0;
 int kill_signalled = 0;
 int hup_signalled = 0;
+int chld_signalled = 0;
 int rat_x;
 int rat_y;
 int rat_visible = 1;		/* rat is visible by default */
@@ -61,6 +63,7 @@ screen_info *screens;
 int num_screens;
 Display *dpy;
 
+struct rp_child_info child_info;
 struct rp_defaults defaults;
 
 int ignore_badwindow = 0;
@@ -201,6 +204,33 @@ alrm_handler (int signum)
   alarm_signalled++;
 }
 
+void
+chld_handler (int signum)
+{
+  int pid, status, serrno;
+  serrno = errno;
+
+  while (1)
+    {
+      pid = waitpid (WAIT_ANY, &status, WNOHANG);
+      if (pid <= 0)
+	break;
+
+      PRINT_DEBUG("Child status: %d\n", WEXITSTATUS (status));
+
+      /* Tell ratpoison about the CHLD signal. We are only interested
+	 in reporting commands that failed to execute. These processes
+	 have a return value of 127 (according to the sh manual). */
+      if (WEXITSTATUS (status) == 127)
+	{
+	  chld_signalled = 1;
+	  child_info.pid = pid;
+	  child_info.status = status;
+	}
+    }
+  errno = serrno;  
+}
+
 int
 handler (Display *d, XErrorEvent *e)
 {
@@ -537,6 +567,7 @@ main (int argc, char *argv[])
   set_sig_handler (SIGTERM, sighandler);
   set_sig_handler (SIGINT, sighandler);
   set_sig_handler (SIGHUP, hup_handler);
+  set_sig_handler (SIGCHLD, chld_handler);
 
   /* Setup ratpoison's internal structures */
   init_defaults();