Mailinglist Archive: opensuse (2532 mails)

["Brian K. White" <brian@xxxxxxxxx>]

----- Original Message ----- 
From: "Jan Engelhardt" <jengelh@xxxxxxxxxxxxxxx>
To: <opensuse@xxxxxxxxxxxx>
Sent: Thursday, May 01, 2008 2:59 AM
Subject: Re: [opensuse] regexp -- defference between \< and \b ? (fwd)


> On Wednesday 2008-04-30 15:53, Randall R Schulz wrote:
> > > >>
> > > >> With regular expressions, what is the difference between \< and
> > > >> \b ? The man page says:
> > > >
> > > > Which man page? ...
> > >
> > > Actually it comes from man grep. Specifically:
> > >
> > >     The Backslash Character and Special Expressions
> > >         The symbols \< and \> respectively match the empty string at
> > > the beginning and end of a word.  The symbol \b matches the empty
> > > string at the edge of a word, ...
> >
> > I guess it's been a long time since I've read the man page for the grep
> > family. I didn't realize \b and \B were a part of Gnu grep.
>
> PCRE does not seem to know \<, so \b is what you would want these days.
>
> \< and \> seem archaic, there does not seem to be a \<-based pattern
> that could not be expressed with \b.

Isn't that like saying any line boundary is the same as begining of line?

To me \< and \> are exactly as useful as ^ and $

Or is the argument that you get the same thing as , \< or \> naturally by 
where you place any further expression context in relation to \b? ie: 
\bstuff or \b.* automatically = \<  and stuff\b or .*\b automatically = \> ? 
does that actually work out? Say if you wanted to match simply the begining 
of every word, or the beginning of the nth word after/before some other 
expression, etc.. but you don't know or care what the word itself is.

--
Brian K. White    brian@xxxxxxxxx    http://www.myspace.com/KEYofR
+++++[>+++[>+++++>+++++++<<-]<-]>>+.>.+++++.+++++++.-.[>+<---]>++.
filePro  BBx    Linux  SCO  FreeBSD    #callahans  Satriani  Filk!





--
To unsubscribe, e-mail: opensuse+unsubscribe@xxxxxxxxxxxx
For additional commands, e-mail: opensuse+help@xxxxxxxxxxxx