Any way to use "POSIX Extended Regular Expressions"?

Lightknight has asked for the wisdom of the Perl Monks concerning the following question:

Hi,

I need some regexps to match consistently in perl and MySQL.

MySQL doesn't use Perl compatible regular expressions but "MySQL uses Henry Spencer's implementation of regular expressions".

And there is a way to use Perl compatible regular expressions in MySQL but that requires modification of the MySQL server, and I'd like to avoid that. I'm surprised I can't find a way (even on CPAN?) to use exactly "POSIX Extended Regular Expressions" in perl. (Which is not the same as /foo/x)

Am I missing something obvious? Is there a way to match against "POSIX Extended Regular Expressions" in perl?

Comment on Any way to use "POSIX Extended Regular Expressions"?

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Re: Any way to use "POSIX Extended Regular Expressions"? by Khen1950fx (Canon) on May 21, 2010 at 10:32 UTC
Take a look at POSIX::Regex by jettero, specifically the REG_EXTENDED option.	[reply]
Re^2: Any way to use "POSIX Extended Regular Expressions"? by Lightknight (Beadle) on May 21, 2010 at 10:53 UTC
How could I have missed that? It's perfect! Thanks BTW: I wish there was a way to navigate the tree easily so I could find all packages =~ /^POSIX::/ such as in http://cpan.uwinnipeg.ca/search?query=^POSIX%3A%3A&mode=module Thanks again, Peter	[reply]
Re^2: Any way to use "POSIX Extended Regular Expressions"? by jettero (Monsignor) on May 21, 2010 at 13:42 UTC
I ♥ you for the mention. -Paul	[reply]
Re: Any way to use "POSIX Extended Regular Expressions"? by moritz (Cardinal) on May 21, 2010 at 10:22 UTC
Since version 5.10 perl supports pluggable regex engines, and there's re::engine::PCRE on CPAN that should pretty much do what you want.	[reply]
Re^2: Any way to use "POSIX Extended Regular Expressions"? by ambrus (Abbot) on May 21, 2010 at 13:21 UTC
You must mean re::engine::POSIX or re::engine::TRE. These modules, which give you posix regular expressions got pulled from CPAN, but you can still find them on backpan. They interpret the /x re option as the regex being an extended re.	[reply]
Re^3: Any way to use "POSIX Extended Regular Expressions"? by Lightknight (Beadle) on May 25, 2010 at 09:48 UTC
In perldoc POSIX::Regex, jettero writes: Yes, I'm aware there's special support for alternate regular expression systems in perl 5.10.x ... let me know when people are done with perl 5.6 and 5.8 and I'll delete this from CPAN. Thanks. I'm assuming that is a reference to re::engine::.* packages on CPAN that got pulled. But I've never heard of backpan before this. I would like to move forward in a way least likely to cause problems in the future. re::engine::.* seems to provide the cleanest syntax, but until I know better I prefer CPAN to "backpan" packages. I don't know why they got pulled from CPAN. Does anyone why that happened? Which would you use: POSIX::Regex from CPAN or re::engine::POSIX from backpan?	[reply]
Re^4: Any way to use "POSIX Extended Regular Expressions"? by ambrus (Abbot) on May 25, 2010 at 17:59 UTC
Re^2: Any way to use "POSIX Extended Regular Expressions"? by JavaFan (Canon) on May 21, 2010 at 12:29 UTC
PCRE stands for "Perl Compatible Regular Expressions". Which used to implement a superset of Perl regular expression, but we have since (5.10) caught up. But the OP asked for POSIX regular expressions. Which, except for syntax differences, actually behave differently: `"abc" =~ /.\|../ && print $&;` [download] Prints 'a' with Perl, but a POSIX style regexp engine would result in 'ab' being printed. With POSIX style, "longest" trumps "leftmost".	[reply] [d/l]
Re^2: Any way to use "POSIX Extended Regular Expressions"? by Lightknight (Beadle) on May 21, 2010 at 10:49 UTC
Thanks for your reply, but as I said in my original post: "MySQL doesn't use Perl compatible regular expressions"	[reply]


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