Yes, my brain was asleep today an forgot to throw in the anchors. The
{0,2} construct is a good idea but not required in this instance as the
field cannot exceed 10-characters. Thanks for everyone's help with this.-----Original Message----- From: Lloyd Sartor [mailto:[EMAIL PROTECTED] Sent: Thursday, January 27, 2005 11:50 To: [EMAIL PROTECTED] Cc: Dirk Bremer; perl-win32-users@listserv.ActiveState.com; [EMAIL PROTECTED] Subject: RE: Regex Help The reason that "200412" matches in your first regex is that the first four characters match the pattern (as expected) but there is nothing in the regex that causes the additional characters "12" to result in a mismatch; the regex engine simply ignores them. Adding "$" to the regex (as Mike has done) will disallow any additional characters in the string, and should work as you expected. Furthermore, using * instead of {0,2} will match strings such as 2004-12-01-02-03. <[EMAIL PROTECTED]> Sent by: [EMAIL PROTECTED] 01/27/2005 11:06 AM To: <[EMAIL PROTECTED]>, <perl-win32-users@listserv.ActiveState.com> cc: Subject: RE: Regex Help Dirk, I'm not a regex pro, but this worked for me: /^\d{4}(-\d{2}){0,2}$/ I tested it with this: @test = qw( xxxx 2004 200412 20041201 2004-12 2004-12-01 ); foreach $test (@test) { print "$test : " . ($test =~ /^\d{4}(-\d{2}){0,2}$/ ? "TRUE" : "FALSE") . "\n"; } Regards, Mike -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Dirk Bremer Sent: Thursday, January 27, 2005 10:43 AM To: perl-win32-users Subject: Regex Help I need to test for the following date-type strings: 2004 2004-12 2004-12-01 All of the above would be legal, any other combination would be illegal. I have been using the following data to test the regex: 'xxxx' Should produce a false result. '2004' Should produce a true result. '200412' Should produce a false result. '20041201' Should produce a false result. '2004-12' Should produce a true result. '2004-12-01' Should produce a true result. My first attempt at a regex is /\d{4}(-\d{2})*/. This produces the following result: xxxx is false 2004 is true 200412 is true 20041201 is true 2004-12 is true 2004-12-01 is true I would prefer that '200412' and '20041201' would fail, i.e. be reported as false. I'm not sure what's going on with this regex as I would expect the following: match the first four numeric characters, then match zero or more occurrences of a dash character followed by two numeric characters The next regex /\d{4}(-\d{2})+/ produces the following results: xxxx is false 2004 is false 200412 is false 20041201 is false 2004-12 is true 2004-12-01 is true This is closer, but I also want '2004' to be true. The next regex /\d{4}(?=-\d{2})/ produces the same results as the previous regex: xxxx is false 2004 is false 200412 is false 20041201 is false 2004-12 is true 2004-12-01 is true I've done quite a few regexes in the past but have never used the positive lookahead assertion before because I have never really understood it. Out of the three regexes, I would have expected the first to fulfill my requirements. I do not understand why it is not, although I suspect it has something to do with the dash character. What am I doing wrong here? I should be able to accomplish this test using a single regex, right? Dirk Bremer - Systems Programmer II - ESS/AMS - NISC St. Peters USA Central Time Zone 636-922-9158 ext. 8652 fax 636-447-4471 [EMAIL PROTECTED] www.nisc.cc _______________________________________________ Perl-Win32-Users mailing list Perl-Win32-Users@listserv.ActiveState.com To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs ************************************************************************ ****************** The information contained in this message, including attachments, may contain privileged or confidential information that is intended to be delivered only to the person identified above. If you are not the intended recipient, or the person responsible for delivering this message to the intended recipient, ALLTEL requests that you immediately notify the sender and asks that you do not read the message or its attachments, and that you delete them without copying or sending them to anyone else. _______________________________________________ Perl-Win32-Users mailing list Perl-Win32-Users@listserv.ActiveState.com To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs _______________________________________________ Perl-Win32-Users mailing list Perl-Win32-Users@listserv.ActiveState.com To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs
