Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!usc!elroy.jpl.nasa.gov!jpl-devvax!lwall
From: lwall@jpl-devvax.JPL.NASA.GOV (Larry Wall)
Newsgroups: comp.lang.perl
Subject: Re: What's a Word Boundary?
Message-ID: <11598@jpl-devvax.JPL.NASA.GOV>
Date: 27 Feb 91 00:58:20 GMT
References: <1991Feb26.183337.24976@holos0.uucp>
Reply-To: lwall@jpl-devvax.JPL.NASA.GOV (Larry Wall)
Distribution: usa
Organization: Jet Propulsion Laboratory, Pasadena, CA
Lines: 17

In article <1991Feb26.183337.24976@holos0.uucp> lbr@holos0.uucp (Len Reed) writes:
: The manual speaks of, but does not define, a "word boundary" in
: regular expressions.  I presume that a word is \w+ and that a word
: boundary will match at ^ and $ and at the edges of, but not
: within, \w+ .

That's more or less correct.  \b matches between \w and \W (in either order),
where the beginning and end of the string are considered to be bounded by \W.

: I'm trying to match 6 digit strings, but I don't want to match a
: six digit string that is part of a larger alphanumeric string.
: The following seems to work.  Is it in fact what I want?
: 	/\b\d{6}\b/

Yes.

Larry