Article View: comp.std.unix
Article #391_POSIX_VDISABLE
From: Roland McGrath
Date: Mon, 23 Jul 1990 22:07
Date: Mon, 23 Jul 1990 22:07
29 lines
1686 bytes
1686 bytes
From: mcgrath%tully.Berkeley.EDU@ucbvax.Berkeley.EDU (Roland McGrath)
>From 1003.1 2.10.4 it seems that if _POSIX_VDISABLE is defined as -1 in
<unistd.h>, it is supposed to mean there is no VDISABLE value for any file.
This precludes the value being -1. Was this the intent?
Similarly, 5.7.1.3 says:
If the variable corresponding to NAME has no limit for the path or file
descriptor, the pathconf() and fpathconf() functions shall return -1 without
changing `errno'.
Though in the case of NAME == _PC_VDISABLE, the value in question is not a
"limit", this seems to imply that if pathconf("file", _PC_VDISABLE) returns -1
without changing `errno', then there is no VDISABLE for value for "file".
The problem is that the wording of the standard and the sysconf, pathconf, and
fpathconf functions were designed for boolean options and for limits which are
required to be positive integers. In these cases, -1 is a reasonable
out-of-range value. But _POSIX_VDISABLE is a character value, not restricted
to any specific range, and doesn't fit in right.
--
Roland McGrath
Free Software Foundation, Inc.
roland@ai.mit.edu, uunet!ai.mit.edu!roland
Volume-Number: Volume 20, Number 139
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!jbc From: mcgrath%tully.Berkeley.EDU@ucbvax.Berkeley.EDU (Roland McGrath) Newsgroups: comp.std.unix Subject: _POSIX_VDISABLE Message-ID: <10462@cs.utexas.edu> Date: 23 Jul 90 22:07:06 GMT Sender: jbc@cs.utexas.edu Reply-To: std-unix@uunet.uu.net Organization: Hackers Anonymous International, Ltd., Inc. (Applications Lines: 29 Approved: jbc@cs.utexas.edu (Guest Moderator, John B. Chambers)