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From: composer@chem.bu.edu (Jeff Kellem)
Newsgroups: comp.lang.perl
Subject: Re: path truncation quest
Message-ID: <COMPOSER.91Mar21122116@chem.bu.edu>
Date: 21 Mar 91 17:21:16 GMT
References: <1991Mar21.010547.13331@convex.com>
	<1991Mar21.064642.29427@eng.umd.edu>
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Organization: Boston University Chemistry Department
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In-reply-to: ziegast@eng.umd.edu's message of 21 Mar 91 06:46:42 GMT

In article <1991Mar21.064642.29427@eng.umd.edu> ziegast@eng.umd.edu (Eric W. Ziegast) writes:
 > In article <1991Mar21.010547.13331@convex.com> you write:
 > >Any suggestions on how, given the argument "/directory/sub/100.host.0"
 > >that one could take off the "100.host.0" component, leaving
 > >"/directory/sub" ?
 >
 > But in Perl, there's always a better way of doing things:
 >
 >	   $path =~ s/((\/[^\s\/]+)+)\/([^\s\/]+)/$1/;

You could make the above a tiny bit more readable by writing it as:

	   $path =~ s:((/[^\s/]+)+)/([^\s/]+):$1:;

or, use whatever delimiters you'd like.  That way you don't have to deal
with quoting the slashes.  On the other hand, if I was to write the above,
assuming I didn't want to save the filename component, I'd probably write
it as:

	   $path =~ s|/[^/]*$||;

This would get rid of any trailing slash, but will also turn "/" to ""..
which is probably not what's wanted .. If you wanted to leave any trailing
slash, you could write it as:

	   $path =~ s|[^/]*$||;
or
	   $path =~ s|/[^/]+$||;

There are, of course, other ways of dealing with the problem.  That should
give you a start, though...

Cheers...

			-jeff

Jeff Kellem
Internet: composer@chem.bu.edu