ack (perl?) regexp matching lines where if is the first word

Posted by Gauthier on Stack Overflow See other posts from Stack Overflow or by Gauthier
Published on 2010-04-14T15:15:15Z Indexed on 2010/04/14 15:33 UTC
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regex

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perl

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ack

Hey. I'm finally learning regexps, training with ack. I believe this uses perl regexp.

I want to match all lines where the first non-blank characters are if (<word> !, with any number of spaces in between the elements.

This is what I came up with:

^[ \t]*if *\(\w+ *!

It only nearly worked. ^[ \t]* is wrong, since it matches one or none [space or tab]. What I want is to match anything that may contain only space or tab (or nothing).

For example these should not match:

// if (asdf != 0)
else if (asdf != 1)

How can I modify my regexp for that?

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