Regex won't match.

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

To the most erudite Perl savants,

I have the following regex

s/^ \s* (?<term> \b\w+\b|(?:'.+?')|(?:".+?") )//isx

Because I will use part of that regex in another piece of code, I am trying to simplify things by having the variable $TERMSDEF hold this text:

\b\w+\b|(?:'.+?')|(?:".+?")

and then interpolating it into the regex like so:

s/^ \s* (?<term> $TERMSDEF)//isx

But now the code that matched the old regex doesn't match the new regex. What am I doing wrong?

Comment on Regex won't match. Select or Download Code

Replies are listed 'Best First'.
Re: Regex won't match. by Sue D. Nymme (Monk) on Sep 20, 2009 at 22:52 UTC
Probably what you're doing wrong is assigning the string to the variable wrong. But since you didn't show how you did that, it's just a guess. Usually, what you want to do is this: `$TERMSDEF = qr/\b\w+\b\|(?:'.+?')\|(?:".+?")/;` That will preserve all the regex semantics, keep your code readable, cure cancer, etc.	[reply] [d/l]
Re^2: Regex won't match. by ikegami (Patriarch) on Sep 21, 2009 at 02:19 UTC
To be equivalent, it should be: `$TERMSDEF = qr/\b\w+\b\|(?:'.+?')\|(?:".+?")/isx;` [download] Mind you, the "i" and "x" are useless here, but the "s" is necessary.	[reply] [d/l]
Re^2: Regex won't match. by Anonymous Monk on Sep 20, 2009 at 22:57 UTC
Excellent! It works now. Thank you.	[reply]
Re: Regex won't match. by ikegami (Patriarch) on Sep 21, 2009 at 02:20 UTC
What am I doing wrong? Hard to tell, since you didn't show us what you did. But I bet if you printed `$TERMSDEF`, you would have noticed it didn't contain what you'd hope it would contain because you didn't escape your slashes properly.	[reply] [d/l]