c# How to exclude a word from Reg Ex?

Question

I have the following expressions.

The only difference between them is route (.gif and .html)

crystal.ipac.caltech.edu - - [17/Jul/1995:20:00:23 -0400] "GET /facts/faq04.gif HTTP/1.0" 200 27063

crystal.ipac.caltech.edu - - [17/Jul/1995:20:00:23 -0400] "GET /facts/faq04.html HTTP/1.0" 200 27063

And this is RegEx which is used for above ones. And it matchs to both of them.

"^([^\\>]+) (\\S+) (\\S+) \\[([\\w:/]+\\s[+\\-]\\d{4})\\] \"(.+?)\" (\\d{3}) (\\d+|-)"

But I need to exclude a first string with .gif extension. How can i do it?

Thanks

Usually such exclusions are implemented using `negative look ahead`. — PM 77-1, Dec 24 '17 at 00:11
Can't you postprocess the matches? Regex are already hard enough to read as it is. — Caramiriel, Dec 24 '17 at 00:13

score 1 · Accepted Answer · answered Dec 24 '17 at 00:26

1

This may suit your needs:

"^([^\\>]+) (\\S+) (\\S+) \\[([\\w:/]+\\s[+\\-]\\d{4})\\] \"(((?!gif).)+?)\" (\\d{3}) (\\d+|-)"

Note the ((?!gif).) ... that's the negative look-around

answered Dec 24 '17 at 00:26

sorak

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Tip: It is more efficient to use `[0-9]` than it is to use `\d` . See https://stackoverflow.com/questions/16621738 – Josh Withee Dec 24 '17 at 05:12

c# How to exclude a word from Reg Ex?

1 Answers1