u option for ar

[Chris Torek]

In article <1034 at necis.UUCP> dhm at 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 at mimsy.umd.edu	Path:	uunet!mimsy!chris