According to Wikipedia, a regular expression (abbreviated regex or regexp) is a sequence of characters that forms a search pattern, mainly for use in pattern matching with strings, or string matching, i.e. "find and replace"-like operations.

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12
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6answers
523 views

What can / should be done with regular expressions?

I've recently learnt regular expressions and I love writing / using them. I'm looking for ideas and more opportunities to use them, however I don't want to overuse them as an all purpose tool, as ...
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1answer
725 views

can a regex search engine for the web be done and if so, how?

I think it would be a great idea if we had a regular expression search engine, but can it be done? It seems impossible since there's no feasible way of indexing such a huge amount of data properly and ...
1
vote
2answers
322 views

Regexp or custom parsing algo?

I was trying to parse a java properties file to avoid some Properties loading pitfalls (non ordering, loss of comments). (Property are of the form 'key = value' where the value can span on multiple ...
36
votes
0answers
4k views

What does the Jamie Zawinski's quotation about regular expressions mean? [duplicate]

In a message to comp.emacs.xemacs, Jamie Zawinski once said: Some people, when confronted with a problem, think "I know, I'll use regular expressions." Now they have two problems. I've always ...
76
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25answers
14k views

How far should one take e-mail address validation?

I'm wondering how far people should take the validation of e-mail address. My field is primarily web-development, but this applies anywhere. I've seen a few approaches: simply checking if there is ...