Regex is matching all combinations

Question

I have the following text below. How do I write the regex to capture all text related to REQ_XXX?

This is my expression .*(REQ_.*)\|, but it captures |3 |4 |5. I just want it to stop after the first | it sees.

Answer 1

You can use :

.*(REQ_[^|]*)\|

The "|" character will be exclude.

Answer 2

Edit:

.*(REQ_.*?)\|

The trick is ? tells preceding .* to stop as early as possible. This way the first | that follows terminates the scope of .*. This is exactly what you want.

My old answer is below. It works well but I think the above is The Right Way.

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Old answer:

.* matches (almost) everything, including |. Use [^|\n]* to match everything but | and newline.

.*(REQ_[^|]*)\|

\n is needed because pure [^|]* could span its match over multiple lines. I guess you don't want this.

Answer 3

Some of the solutions are already posted in other answers, I'm giving a summary here.

You can follow multiple approaches here, you need to decide based on your needs which one you use:

1. give a positive list of characters appearing in your code:
   .*(REQ_[\w]+)[\s]*\|
   • in this case [\w]+ matches all word characters (letters, numbers and "_")
   • whitespaces before | are not included in your captured result ([\s]* is out of the brackets)
2. give a negative list of characters, where you want your regex to stop:
   .*(REQ_[^|]+)\|
3. use lazy match to stop at first possibility: .*(REQ_.+?)\|

Answer 4

If REQ_ is allways followed by word characters, you can simply use REQ_w+ or if you don't want to match ABCREQ_123, use a word boundary: \bREQ_\w+.

See in action