Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!ncar!tank!mimsy!chris
From: chris@mimsy.UUCP (Chris Torek)
Newsgroups: comp.unix.questions
Subject: Re: u option for ar
Keywords: ar
Message-ID: <17335@mimsy.UUCP>
Date: 6 May 89 04:05:50 GMT
References: <1034@necis.UUCP>
Distribution: usa
Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742
Lines: 24

In article <1034@necis.UUCP> dhm@necis.UUCP (Dave Mitchell) writes:
>... I have used ar with the u option but couldn't determine what it
>does. The source code wasn't a help either.

It was for me :-)

According to the source, `ar u' is an alias for `ar r', except that
it will not replace the sub-file in the archive unless the real file
is newer.  That is:

	% ar crv foo.a foo.o
	a - foo.o
	% ar rv foo.a foo.o
	r - foo.o
	% ar uv foo.a foo.o
	% touch foo.o
	% ar uv foo.a foo.o
	r - foo.o
	%

(and I even tested it, after writing this :-) )
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7163)
Domain:	chris@mimsy.umd.edu	Path:	uunet!mimsy!chris