If the handler for SIGCHLD is set to SIG_IGN, act as if the

SA_NOCLDWAIT (don't create zombies) flag has been specified.  This
is consistent with most other operating systems and is what XPG4.2
specifies.

1 files changed, 25 insertions, 1 deletions

diff --git a/lib/libc/gen/signal.3 b/lib/libc/gen/signal.3
index 4d0c379267a..d694fb107f7 100644
--- a/lib/libc/gen/signal.3
+++ b/lib/libc/gen/signal.3
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: signal.3,v 1.16 2001/11/07 18:46:58 deraadt Exp $
+.\"	$OpenBSD: signal.3,v 1.17 2002/01/07 16:16:32 millert Exp $
 .\"
 .\" Copyright (c) 1980, 1991, 1993
 .\"	The Regents of the University of California.  All rights reserved.
@@ -160,6 +160,30 @@ automatically blocked and
 .Fa func
 is called.
 .Pp
+If the
+.Fa func
+is set to
+.Dv SIG_IGN
+for the
+.Dv SIGCHLD
+signal, the system will not create zombie processes when children of
+the calling process exit.
+If the calling process subsequently issues a
+.Xr wait 2
+(or equivalent), it blocks until all of the calling process's child
+processes terminate, and then returns a value of \-1 with
+.Va errno
+set to
+.Dv ECHILD .
+.Bf -symbolic
+This differs from historical
+.Bx
+behavior but is consistent with
+.At V
+as well as the
+.St -xpg4.2 .
+.Ef
+.Pp
 The handled signal is unblocked when
 .Fa func
 returns and