Re: questions of a perl beginner on regex

Others have answered your question. Basically you have three different types of question marks: ?:, \? and ? - non capturing matching, escaping, and zero or more matches. But looking at that regex, I wonder if it's all just overkill. It looks like your matching a flash url that may have paramaters. I wonder if this simpler regex will do the job as well:

m/\.swf.*$/oi
[download]

Comments? I know some people wish death to dot-star but what's the downside here?

-derby

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Re^2: questions of a perl beginner on regex by jhourcle (Prior) on Jun 20, 2006 at 13:52 UTC
Maybe, maybe not. I think it's overkill, but your proposal is too simple. It might cause false matches if there were a 'www.swf.com' (or even 'www.swfa.com') I'd probably use something like: `m/[.]swf(?:$\|[?])/i` if we're not capturing, there's no reason to need '.*' to get the rest of the line, so a simple alternate (end of line, or a question mark), will work just fine. It's almost as few characters to use the following, and there would hopefully be less confusion about what it's doing for novices: `m/\.swf$\|\.swf\?/i`	[reply] [d/l] [select]

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Re^2: questions of a perl beginner on regex
by jhourcle (Prior) on Jun 20, 2006 at 13:52 UTC

Maybe, maybe not. I think it's overkill, but your proposal is too simple. It might cause false matches if there were a 'www.swf.com' (or even 'www.swfa.com')

I'd probably use something like:

m/[.]swf(?:$|[?])/i

if we're not capturing, there's no reason to need '.*' to get the rest of the line, so a simple alternate (end of line, or a question mark), will work just fine.

It's almost as few characters to use the following, and there would hopefully be less confusion about what it's doing for novices:

m/\.swf$|\.swf\?/i

[reply]
[d/l]
[select]