simple regexp question

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

Replies are listed 'Best First'.
Re: simple regexp question by osunderdog (Deacon) on Feb 10, 2006 at 13:05 UTC
Use `?` To indicate a character that can appear zero or one time. For example: `$ perl -e "print '2000-20-30' =~ /\d{4}-?\d{2}-?\d{2}/" 1 $ perl -e "print '20002030' =~ /\d{4}-?\d{2}-?\d{2}/" 1` [download] Hazah! I'm Employed!	[reply] [d/l] [select]
Re: simple regexp question by davorg (Chancellor) on Feb 10, 2006 at 13:06 UTC
Try the most excellent documentation: perldoc perlretut perldoc perlreref (Hint: \| for "or", but you probably want ? instead) -- <http://dave.org.uk> "The first rule of Perl club is you do not talk about Perl club." -- Chip Salzenberg	[reply]
Re: simple regexp question by thedoe (Monk) on Feb 10, 2006 at 15:10 UTC
Instead of using a regex to parse your dates, why not use one of the pre-built modules in CPAN for date parsing? Date::Parse is the first that comes to mind. It is simple to use and will parse just about any common date format. This means that even if the date input changes, your code probably won't have to.	[reply]
Re: simple regexp question by misterb101 (Sexton) on Feb 10, 2006 at 14:59 UTC
Hi, what exactly is 2005100? 2005-1-00 ? 2005-10-0 ? if you don't know how many chars a month/day can have you can never create a clever enough regexp to my humble opinion Rob	[reply]
Re^2: simple regexp question by duff (Parson) on Feb 10, 2006 at 15:13 UTC
It could be that his dates are 4 digit year followed by 3 digit julian day; no one said anything about month/day. duff	[reply]
Re^3: simple regexp question by misterb101 (Sexton) on Feb 10, 2006 at 15:30 UTC
Mixing the Gregorian (2005) and Julian (001) calendar? is that very likely?	[reply]
Re: simple regexp question by grinder (Bishop) on Feb 10, 2006 at 17:21 UTC
Maybe I'm missing something really obvious, but if the - (dash) is optional, then mark it such in the regular expression... `my ($year, $num) = ($_ =~ /^(\d{4})-?(\d+)$/);` [download] This way you will be guaranteed of getting both parts, regardless of whether a dash is present or not. • another intruder with the mooring in the heart of the Perl	[reply] [d/l]