How can I use regex to get the part of a string between two specific characters ":" and "@"?

Question

How I can get part of SIP URI? For example I have URI sip:username@sip.somedomain.com, I need get just username and I use [^sip:](.*)[$@]+ expression, but appeared result is username@. How I can exclude from matching @?

Who was looking for a regex to match middle characters in a string: [How to match the middle character in a string with regex?](https://stackoverflow.com/questions/28051651/how-to-match-the-middle-character-in-a-string-with-regex), [finding middle character in string using regex only](https://stackoverflow.com/questions/17313214/finding-middle-character-in-string-using-regex-only) — bobble bubble, Dec 29 '22 at 13:55

score 8 · Accepted Answer · answered Mar 17 '13 at 22:58

8

this should do the job

(?<=^sip:)(.*)(?=[$@])

answered Mar 17 '13 at 22:58

VladL

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score 1 · Answer 2 · answered Mar 17 '13 at 22:59

Use a lookahead instead of actually matching @:

^sip:(.*?)(?=@|\$)

Either you are using a very strange regex flavor, or your starting character class is a mistake. [^sip:] matches a single character that isn't any of s,i,p or :. I am also not certain what the $ character is for, since that isn't a part of SIP syntax.

score 1 · Answer 3 · answered Mar 17 '13 at 23:04

If lookaheads are not available in your regex flavour (for instance POSIX regexes lack them), you can still match parts of the string in your regex you don't eventually want to return, if you use capture groups and only grab the contents of some of them.

For example

^sip:(.*?)[$@]+ Then only return the contents of the first capture group

How can I use regex to get the part of a string between two specific characters ":" and "@"?

3 Answers3

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