Perl extended regexp problems...
Liyang Hu
liyang at nerv.cx
Sun Sep 16 08:48:58 CDT 2001
Hi,
On Sun, Sep 16, 2001 at 08:51:33AM -0400, Wesley Darlington wrote:
> On Sun, Sep 16, 2001 at 10:12:30AM +0100, Liyang Hu wrote:
> > echo -e "foobar\ncowbar\ncowmoo" | perl -ne 'print if /(?<!=cow)bar/x'
> Do you have a superfluous equals sign in there...? /(?<!cow)bar/
I do? O_O
Perl in a Nutshell (First Edition, December 1998) tells me:
----8<----
4.6.8 Extended Regular Expressions
(?<!=...)
A zero-width negative lookbehind assertion. For example,
/(?<!=bad)boy/ matches any occurrence of "boy" that doesn't
follow "bad". This only works for fixed-width lookbehind.
----8<----
Grr... This is the last time I read the FM. -_-
^^;;;
/Liyang
--
.----| Liyang Hu /aka/ DenseBoy |---| http://www.nerv.cx/ |----.
| drug, n: A substance that, when injected into a rat, |
| produces a scientific paper. |
More information about the Belfast-pm
mailing list