New source file for manipulating atom-valued window properties.

[xtoys] / xwait.c

diff --git a/xwait.c b/xwait.c
index 06e0e5c..c74d2e2 100644 (file)
--- a/xwait.c
+++ b/xwait.c
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: xwait.c,v 1.3 1998/11/21 22:30:27 mdw Exp $
+ * $Id: xwait.c,v 1.7 1999/06/19 23:42:37 mdw Exp $
  *
  * Wait until prodded by another X client
  *
@@ -29,6 +29,18 @@
 /*----- Revision history --------------------------------------------------* 
  *
  * $Log: xwait.c,v $
+ * Revision 1.7  1999/06/19 23:42:37  mdw
+ * Improve signal handling.
+ *
+ * Revision 1.6  1998/12/11 09:50:07  mdw
+ * Minor modifications to work with mLib and mgLib.
+ *
+ * Revision 1.5  1998/11/30 22:36:53  mdw
+ * Tidy up tabbing in help texts very slightly.
+ *
+ * Revision 1.4  1998/11/21 22:41:19  mdw
+ * Reap children which die before I get my signal handler installed.
+ *
  * Revision 1.3  1998/11/21 22:30:27  mdw
  * Support GNU-style long options throughout, and introduce proper help
  * text to all programs.  Update manual pages to match.
@@ -44,6 +56,7 @@
 
 /*----- Header files ------------------------------------------------------*/
 
+#include <errno.h>
 #include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -56,8 +69,9 @@
 #include <X11/Xlib.h>
 #include <X11/Xutil.h>
 
-#include "mdwopt.h"
-#include "quis.h"
+#include <mLib/mdwopt.h>
+#include <mLib/quis.h>
+
 #include "xwait.h"
 
 /*----- Main code ---------------------------------------------------------*/
@@ -66,8 +80,10 @@
 
 static void sigchld(int sig)
 {
+  int e = errno;
   while (waitpid(-1, 0, WNOHANG) > 0)
     ;
+  errno = e;
 }
 
 /* --- @main@ --- */
@@ -135,7 +151,7 @@ int main(int argc, char *argv[])
 "-d, --display=DISPLAY Choose X display to connect to\n"
 "-f, --force           Run even if this property is waited for by another\n"
 "                      process\n"
-"-a, --atom=ATOM               Choose property name to listen for\n"
+"-a, --atom=ATOM\t     Choose property name to listen for\n"
 "-m, --msg=MSG         Choose value of property to wait for\n",
           stdout);
        exit(0);
@@ -222,12 +238,26 @@ int main(int argc, char *argv[])
 
   {
     struct sigaction sa;
+    sigset_t ss, oss;
+
+    /* --- Set the handler up --- */
 
     sa.sa_handler = sigchld;
     sigemptyset(&sa.sa_mask);
     sigaddset(&sa.sa_mask, SIGCHLD);
-    sa.sa_flags = 0;
+    sa.sa_flags = SA_NOCLDSTOP;
+#ifdef SA_RESTART
+    sa.sa_flags |= SA_RESTART;
+#endif
     sigaction(SIGCHLD, &sa, 0);
+
+    /* --- Now reap any which have been waiting around so far --- */
+
+    sigemptyset(&ss);
+    sigaddset(&ss, SIGCHLD);
+    sigprocmask(SIG_BLOCK, &ss, &oss);
+    sigchld(SIGCHLD);
+    sigprocmask(SIG_SETMASK, &oss, 0);
   }
 
   /* --- Now wait for an event --- */