help related to regular expression

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

Hi , i am working with regular expression and got into trouble how to differentiate between two patterns


LETTER          [A-Za-z]
DIGIT           [0-9]
LABELNAME       {LETTER}(_|{LETTER}|{DIGIT})*
[download]

the above rule of labelname will accept anything. now i want to have another rule

REGNAME        [pP] 
REG_NUM        [0-9]+
[download]

if i use first one i need to do further coding to get value of reg_num numerical value that why i want to use second one. problem is second rule fits in 1 rule also and so i get error results. is there any way i can have differen rules for second case and just able to have recognized patterns like p0 , P2 from second rule so that i dont need to do extra calculation to extract values as would have been in first case. Thanks

Comment on help related to regular expression Select or Download Code

Replies are listed 'Best First'.
Re: help related to regular expression by lidden (Curate) on Mar 04, 2010 at 07:56 UTC
I do not know if I understand your question correctly. If you want to match a 'p' followed by some digits you can do it like this. `my $string = 'p23'; if($string =~ /[pP](\d+)/){ print $1 }'` [download]	[reply] [d/l]