From 27eed90c425c407a7232dd69d5b30c6b56693de7 Mon Sep 17 00:00:00 2001 From: dholland Date: Mon, 2 Jan 2012 15:55:29 +0000 Subject: [PATCH] Clarify the behavior of exit(x) for out-of-range x. PR 45769 --- lib/libc/stdlib/exit.3 | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-) diff --git a/lib/libc/stdlib/exit.3 b/lib/libc/stdlib/exit.3 index 27ee4d931062..7668f62a3544 100644 --- a/lib/libc/stdlib/exit.3 +++ b/lib/libc/stdlib/exit.3 @@ -1,4 +1,4 @@ -.\" $NetBSD: exit.3,v 1.14 2003/08/07 16:43:39 agc Exp $ +.\" $NetBSD: exit.3,v 1.15 2012/01/02 15:55:29 dholland Exp $ .\" .\" Copyright (c) 1990, 1991, 1993 .\" The Regents of the University of California. All rights reserved. @@ -33,7 +33,7 @@ .\" .\" from: @(#)exit.3 8.1 (Berkeley) 6/4/93 .\" -.Dd August 11, 2002 +.Dd January 2, 2012 .Dt EXIT 3 .Os .Sh NAME @@ -78,11 +78,19 @@ Following this, .Fn exit calls .Xr _exit 2 . -Note that typically -.Xr _exit 2 -only passes the lower 8 bits of +.Sh RESTRICTIONS +Standard C guarantees only that the values zero, +.Dv EXIT_SUCCESS , +and +.Dv EXIT_FAILURE +produce meaningful results. +POSIX extends this to guarantee that the +least significant 8 bits of .Fa status -on to the parent, thus negative values have less meaning. +are preserved and returned to the parent via +.Xr wait 2 . +Values outside the supported range 0-255 are bitwise-truncated; therefore, +negative values should not be used. .Sh RETURN VALUES The .Fn exit