From: Eric Blake <eblake@redhat.com>
To: cygwin@cygwin.com
Subject: Re: Redirecting output from running proc doesn't modify the "last modified time" field for target file
Date: Fri, 02 Dec 2011 20:05:00 -0000 [thread overview]
Message-ID: <4ED92F64.4060905@redhat.com> (raw)
In-Reply-To: <CAG_2cTm+VQcNuRmDTFEheEyuOAeWA4tCW5+whH74E6D4UkAFAg@mail.gmail.com>
[-- Attachment #1: Type: text/plain, Size: 909 bytes --]
On 12/02/2011 11:50 AM, Jon Clugston wrote:
> While this loop is running, the timestamp on "x.log" doesn't change
> (whereas on Linux it changes every 10 seconds). It sure looks to me
> that Windows just doesn't bother updating the file timestamp while it
> is open. I don't know if this update is required by POSIX - I would
> doubt that it is.
POSIX requires that any write() to an open file mark it for update; the
update doesn't have to occur right away (so you can batch up several
writes, but only change the mtime metadata once at the end of the
batch), but it DOES require that stat() and several similar functions
flush all marked updates prior to exposing timestamps to the user. So
yes, Windows is violating POSIX, and I have no idea whether cygwin can
work around it.
--
Eric Blake eblake@redhat.com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 620 bytes --]
next prev parent reply other threads:[~2011-12-02 20:05 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-02 16:51 ajshower
2011-12-02 17:20 ` Jon Clugston
2011-12-02 18:43 ` ajshower
2011-12-02 18:50 ` Jon Clugston
2011-12-02 20:05 ` Eric Blake [this message]
2011-12-03 20:37 ` Corinna Vinschen
2011-12-03 20:58 ` Christopher Faylor
2011-12-02 20:23 ` Eliot Moss
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4ED92F64.4060905@redhat.com \
--to=eblake@redhat.com \
--cc=cygwin@cygwin.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).