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Re:Detailed guide on Regex by jwilk on Tuesday July 25, 2017 @10:07AM (#14847779)
There are many incompatible regexp dialects. This describes one of the dialects, but it doesn't even say which one.

It is full of errors and omissions. It's certainly not "detailed".

I don't recommend this as a learning source. Sorry.

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Re:Detailed guide on Regex by tyingq on Tuesday July 25, 2017 @09:42AM (#14847627)
"Just like above example the regular expression ar[.] means: an lowercase character a, followed by letter r, followed by any character."

A period inside a character class is just a period. So that's only going to match "ar."

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Re:Detailed guide on Regex by ggus on Tuesday July 25, 2017 @10:39AM (#14848035)
the example is even worse: the string should match three times, not two. (it misses the a, followed by r, followed by space)
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Re:Detailed guide on Regex by ddebernardy on Tuesday July 25, 2017 @09:43AM (#14847631)
Haven't read the guide, but off the bat it would benefit by at least mentioning the potential for regex with poor performance characteristics or even catastrophic backtracking, and give a few tips on how to avoid them. Neither performance nor backtracking appear in the text anywhere, nor do possessive or atomic.
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Re:Detailed guide on Regex by tyingq on Tuesday July 25, 2017 @09:53AM (#14847690)
Word boundaries aren't mentioned either. I use \b quite a bit, was surprised to see it skipped.
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