Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!apple!bionet!ames!dftsrv!mimsy!mojo!ziegast
From: ziegast@eng.umd.edu (Eric W. Ziegast)
Newsgroups: comp.lang.perl
Subject: Re: path truncation quest
Keywords: path,truncation
Message-ID: <1991Mar21.064642.29427@eng.umd.edu>
Date: 21 Mar 91 06:46:42 GMT
References: <1991Mar21.010547.13331@convex.com>
Sender: news@eng.umd.edu (C-News)
Organization: University of Merryland, Engineering Computing Services
Lines: 38

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" ?

At first, I thought about using an array:

	@tmp = split(/\//,$path);
	$dir = join("/",pop(@tmp));

But in Perl, there's always a better way of doing things:

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

A simplified version would be:

	/((\/F)+)+)\/(F)/

	F matches a one word file/directory name.
		In my example I use [^\s\/]+ which simply matches
		any word without whitespace or "/" in it.
		You may want to use something more strict instead.

	$1 will match the directory path.  (man dirname)
	$2 is used only for /F grouping
	$3 will match the base name.  (man basename)

This is, of course, only if it's a full path name.  Anything else
won't match (and won't be changed).


--
Perl - 1. (n) The Mother of All Languages
       2. (v) To convert an otherwise boring program to use Perl.
	  [-ed, -ing]
________________________________________________________________________
Eric W. Ziegast, University of Merryland, Engineering Computing Services
ziegast@eng.umd.edu - Eric@(301.405.3689)