Rewrite the wgfile on SIGUSR1.

4 files changed, 41 insertions, 14 deletions

diff --git a/zwgc/main.c b/zwgc/main.c
index 83413da..52b9e7a 100644
--- a/zwgc/main.c
+++ b/zwgc/main.c
@@ -461,6 +461,12 @@ static RETSIGTYPE signal_child()
   errno = old_errno;
 }
 
+/* rewrite the wgfile in case it has gone away */
+static RETSIGTYPE signal_usr1()
+{
+    write_wgfile();
+}
+
 static void setup_signals(dofork)
      int dofork;
 {
@@ -493,6 +499,9 @@ static void setup_signals(dofork)
     sa.sa_handler = signal_child;
     sigaction(SIGCHLD, &sa, (struct sigaction *)0);
 
+    sa.sa_handler = signal_usr1;
+    sigaction(SIGUSR1, &sa, (struct sigaction *)0);
+
 #else /* !POSIX */
     if (dofork) {
 	/* Ignore keyboard signals if forking.  Bad things will happen. */
@@ -510,6 +519,7 @@ static void setup_signals(dofork)
     signal(SIGHUP, signal_exit);
     signal(SIGCHLD, signal_child);
     signal(SIGPIPE, SIG_IGN);		/* so that Xlib gets an error */
+    signal(SIGUSR1, signal_usr1);
 #endif
 }
 
diff --git a/zwgc/zephyr.c b/zwgc/zephyr.c
index c3276e5..9ad8dbe 100644
--- a/zwgc/zephyr.c
+++ b/zwgc/zephyr.c
@@ -43,6 +43,9 @@ static const char rcsid_zephyr_c[] = "$Id$";
 extern int zwgc_debug;
 #endif /* DEBUG */
 
+static int zephyr_inited = 0;
+static unsigned short zephyr_port = 0;
+    
 /*
  *  Internal Routine:
  *
@@ -70,6 +73,25 @@ static string get_zwgc_port_number_filename()
 }
 
 /*
+ *  Write out the port number to the wg file.
+ */
+
+void write_wgfile()
+{
+    char *name = get_zwgc_port_number_filename();
+    FILE *port_file;
+
+    port_file = fopen(name, "w");
+    if (port_file) {
+	fprintf(port_file, "%d\n", zephyr_port);
+	fclose(port_file);
+    } else {
+	fprintf(stderr, "zwgc: error while opening %s for writing: ", name);
+	perror("");
+    }
+}
+
+/*
  *
  */
 
@@ -98,8 +120,6 @@ static void handle_zephyr_input(notice_handler)
     }
 }
 
-static int zephyr_inited = 0;
-    
 /*
  *
  */
@@ -107,7 +127,6 @@ static int zephyr_inited = 0;
 void zephyr_init(notice_handler)
      void (*notice_handler)();
 {
-    unsigned short port = 0;           /* Use any old port */
     char *temp;
     char *exposure;
     char *tty = NULL;
@@ -117,14 +136,13 @@ void zephyr_init(notice_handler)
      * Initialize zephyr.  If error, print error message & exit.
      */
     FATAL_TRAP( ZInitialize(), "while initializing Zephyr" );
-    FATAL_TRAP( ZOpenPort(&port), "while opening Zephyr port" );
+    FATAL_TRAP( ZOpenPort(&zephyr_port), "while opening Zephyr port" );
 
     /*
      * Save away our port number in a special place so that zctl and
      * other clients can send us control messages: <<<>>>
      */
     temp = get_zwgc_port_number_filename();
-    errno = 0;
     port_file = fopen(temp, "r");
     if (port_file) {
 	fprintf(stderr, "zwgc: windowgram file already exists.  If you are\n");
@@ -132,14 +150,7 @@ void zephyr_init(notice_handler)
 	fprintf(stderr, "zwgc: and try again.\n");
 	exit(1);
     }
-    port_file = fopen(temp, "w");
-    if (port_file) {
-	fprintf(port_file, "%d\n", port);
-	fclose(port_file);
-    } else {
-	fprintf(stderr, "zwgc: error while opening %s for writing: ", temp);
-	perror("");
-    }
+    write_wgfile();
 
     /* Set hostname and tty for locations.  If we support X, use the
      * display string for the default tty name. */
diff --git a/zwgc/zephyr.h b/zwgc/zephyr.h
index d2e3735..98265df 100644
--- a/zwgc/zephyr.h
+++ b/zwgc/zephyr.h
@@ -19,5 +19,6 @@
 
 extern void zephyr_init();
 extern void finalize_zephyr();
+extern void write_wgfile();
 
 #endif
diff --git a/zwgc/zwgc.1 b/zwgc/zwgc.1
index 48ab388..880d2ad 100644
--- a/zwgc/zwgc.1
+++ b/zwgc/zwgc.1
@@ -963,7 +963,12 @@ SIGINT, SIGQUIT, and SIGTSTP are ignored because they can be sent
 inadvertently, and bizarre side-effects can result.  If you want them
 to be acted on, then run
 .I zwgc -nofork &
-
+.PP
+If
+.I zwgc
+receives a SIGUSR1, it will rewrite the file used to store the
+WindowGram port number ($WGFILE or /tmp/wg.\fIuid\fR), in the event
+that the file has been lost.
 .SH CONTROL MESSAGES
 In order to allow some special user controls over the behavior of
 .IR zwgc ,