Newsgroups: comp.compilers Path: gmd.de!xlink.net!sol.ctr.columbia.edu!math.ohio-state.edu!cs.utexas.edu!swrinde!elroy.jpl.nasa.gov!ames!olivea!hal.com!decwrl!world!iecc!compilers-sender From: h...@zoo.toronto.edu (Henry Spencer) Subject: Re: Regular expression implementations ? Message-ID: <93-08-038@comp.compilers> Keywords: lex, DFA Sender: compilers-sen...@chico.iecc.com Organization: U of Toronto Zoology References: <93-08-031@comp.compilers> <93-08-035@comp.compilers> Date: Sat, 7 Aug 1993 23:14:02 GMT Approved: compil...@chico.iecc.com Lines: 31 arn...@cc.gatech.edu (Arnold Robbins) writes: >>Where can I find information on regular expressions implementations in C? > >Two and a half choices. >1) Flex, which is a lex clone... >2) Gnu regex, prep.ai.mit.edu:/pub/gnu/regex-0.12.tar.gz (slow) >3) Gnu RX, a regex re-implementation... >[There's more regexps than that. What about Henry Spencer's package? -John] In fact, there are at least two more, because I wrote them both. :-) There's my old package, dating back to 1986 or thereabouts, which is in widespread use (including several commercial products -- it helps that its copyright terms are much more liberal than the GNU ones). A slightly updated version of that will appear in a few months, in conjunction with a new book -- Software Solutions In C, ed. Dale Schumacher, Academic Press -- which will have a chapter (by me) that walks through the code explaining how it works. Meanwhile, you can find the old code lots of places, including zoo.toronto.edu/dtr/regexp.shar . Then there's my new one, which is the regular-expression implementation shipping with 4.4BSD. The good news is that it's completely POSIX.2 compliant. The bad news is that it's pretty slow; it's basically an alpha release, and I'd really hoped to get at least to a beta before 4.4 shipped, but that didn't happen. Eventually there will be a faster release, but don't ask me to set a date just yet. -- Henry Spencer @ U of Toronto Zoology, h...@zoo.toronto.edu utzoo!henry -- Send compilers articles to compil...@iecc.com or {ima | spdcc | world}!iecc!compilers. Meta-mail to compilers-requ...@iecc.com. |