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From: guy%gorodish@Sun.COM (Guy Harris)
Newsgroups: comp.unix.wizards
Subject: Re: BSD to SysV
Message-ID: <31892@sun.uucp>
Date: Fri, 23-Oct-87 21:28:21 EST
Article-I.D.: sun.31892
Posted: Fri Oct 23 21:28:21 1987
Date-Received: Sun, 25-Oct-87 18:44:07 EST
References: <9940@brl-adm.ARPA>
Sender: news@sun.uucp
Lines: 14

> Has anyone figured out how to perform the BSD functions ``fsync()''
> and ``ftruncate()'' in System V?

You can get the same general effect as "fsync" in some S5 implementations by
using "fcntl" to turn the O_SYNC flag on for a file descriptor; this flag
causes all writes to that descriptor to be done synchronously.

Unless you're truncating a file to zero length, you can't do "ftruncate()"
except by making a copy of the file up to the new length, doing a "creat" or
"open" with O_TRUNC to truncate the original file to zero length, and then
copying the truncated copy on top of the original file.
	Guy Harris
	{ihnp4, decvax, seismo, decwrl, ...}!sun!guy
	guy@sun.com