Friends,

I am trying to write a regex for matching "duration" strings. Basically durations are of the form PnYnMnDTnHnMnS with some extra rules which are described in the link provided. Here's what I have so far. 
 #!/usr/bin/perl -w

       while(<DATA>) {
          chomp;
          if ( /^-{0,}P{1,1}T{0,}\d{1,}[Y|M|D|H|S]{1,1}/ ) {
              print "$_ matches\n";
          } else {
              print "$_ NO match\n";
          }
       }
       __DATA__
       PnYnMnDTnHnMnS
       -P1Y
       P3Y3M3DT3H3M3S
       P3M3Y3DT3H3M3S
       P334Y3DT3H3M3S
       PT2H
       5T
       PT
       P5M6DT
       P5M6DT9
       P600T6S

[download]
And here's the output I get ... 
PnYnMnDTnHnMnS NO match
-P1Y matches
P3Y3M3DT3H3M3S matches
P3M3Y3DT3H3M3S matches
P334Y3DT3H3M3S matches
PT2H matches
5T NO match
PT NO match
P5M6DT matches
P5M6DT9 matches
P600T6S NO match

[download]
As you can see my regex is quite cutting it. P5M6DT, P3M3Y3DT3H3M3S, and P5M6DT9 should not match. And tiny brain is fried!

Plankton: 1% Evil, 99% Hot Gas.

In reply to duration regex by Plankton

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