From owner-freebsd-questions Mon Feb 17 1: 3:30 2003 Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 9491A37B401 for ; Mon, 17 Feb 2003 01:03:29 -0800 (PST) Received: from segfault.monkeys.com (segfault.monkeys.com [66.60.157.246]) by mx1.FreeBSD.org (Postfix) with ESMTP id DC9BD43FA3 for ; Mon, 17 Feb 2003 01:03:26 -0800 (PST) (envelope-from rfg@monkeys.com) Received: from monkeys.com (localhost [127.0.0.1]) by segfault.monkeys.com (Postfix) with ESMTP id 954DF41F68 for ; Mon, 17 Feb 2003 01:03:26 -0800 (PST) To: freebsd-questions@freebsd.org Subject: A small question on msgrcv(3) semantics Date: Mon, 17 Feb 2003 01:03:26 -0800 Message-ID: <53158.1045472606@monkeys.com> From: "Ronald F. Guilmette" Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG The man page for msgrcv(3) indicates that any type of message on the specified message queue may be received by setting the `mtype' field of the following value/result structure to zero before issuing the call to msgrcv(3): long mtype; /* message type */ char mtext[1]; /* body of message */ Unfortunately, the man page leaves unspecified whether or not the `mtype' field is itself treated as a value/result parameter to the call. What I mean is: After a call to msgrcv(3) in which mtype was set to zero before the call, will mtype sill be set to zero after the call, or will it receive the mtype value of the message that was received? (For my purposes, the latter behavior would be most helpful.) To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message