From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oleg Goldshmidt Subject: Re: errno i xs_wire.h Date: 08 Nov 2005 18:26:01 +0000 Message-ID: References: <200511081325.18626.mark.williamson@cl.cam.ac.uk> Reply-To: xen-devel@lists.xensource.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: In-Reply-To: <200511081325.18626.mark.williamson@cl.cam.ac.uk> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Mark Williamson Cc: xen-devel@lists.xensource.com, Jacob Gorm Hansen List-Id: xen-devel@lists.xenproject.org Mark Williamson writes: > > playing with xenbus support in mini-os, I noticed that xs_wire.h > > references errno constants such as EINVAL. Is the use of these > > constants (which could be guest-OS specific) > > Isn't the basic set of errno vals posix standardised? So even if a guest OS > doesn't deal in errnos itself, it can just import the BSD errno.h or > similar...? POSIX does not standardise errno *values*. It only specifies a set of symbolic error names and their meanings, and says that all the POSIX symbolic error names must have distinct values. So if you need to share the values between entities that may have different error name/value mappings (even if everybody is POSIX-compliant) you need a conversion protocol. I suppose "man errno" will give you the set of POSIX error names. -- Oleg Goldshmidt | pub@NOSPAM.goldshmidt.org | http://www.goldshmidt.org