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From: streib@silver.ucs.indiana.edu (Allan Streib)
Newsgroups: comp.unix.questions,comp.unix.ultrix,cs.unix.questions
Subject: file and record locking questions (general)
Summary: are they portable across *nix versions?
Keywords: record,locking,ultrix
Message-ID: <1991Mar29.040736.18783@bronze.ucs.indiana.edu>
Date: 29 Mar 91 04:07:36 GMT
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Just a couple of general questions on file and record locking under
UNIX:

(These questions are all based on my study of Ultrix 4.2 man pages)

- flock (2) and lockf (3) can be used to control concurrent access to
files, allowing cooperating processes to perform consistent operations
on files.  I understand that these system calls are advisory, and do
not (apparently) lock the file to non-cooperating processes.

- I can apparently use fcntl (2) with commands FGETLK, FSETLK, and
FSETLKW to facilitate concurrent file acccess. 

These commands are not mentioned in Rochkind's _Advanced UNIX
Programming_ text.  Are these Ultrix enhancements, or are these
portable?

Thanks for any insight. 

-Allan (streib@silver.ucs.indiana.edu)