Matching string using regex

Question

I want to write a regular expression in a C++ program which checks if a string matches the following expression:

a word not containing '_' but it can contain number followed by

'_' followed by

three digits in a row (i.e. 047)

followed by '_' followed by

a string (can contain anything)

I have tried the following expression but it does seem to find the desired string as described above. I suspect the problem lies in the first part but I cannot detect it in order to modify properly:

static const wregex stringForm("([^_]?)_?(\\d{3})_(.+)");

What is then the proper reg expression?

Could you add a concrete example of a string you want matched? — Some programmer dude
– Some programmer dude, Commented Jul 24, 2012 at 12:36
The first to conditions contradict. "Not containing ... " vs. "can contain ... when followed by ...". This logical error reflects in your regexp. — steffen
– steffen, Commented Jul 24, 2012 at 12:40
your example does not match the above description (the description does not ask for leading underscore before 3 digits number). You should provide several examples, some matching, some not matching to maximize changes to get a usefull answer. — kriss
– kriss, Commented Jul 24, 2012 at 12:54
your example does not have "number followed by '_' followed by three digits" — OrangeDog
– OrangeDog, Commented Jul 24, 2012 at 14:42
@OrangeDog the first part of the string should be a word which can contain number as well, not absolutely a number. — arjacsoh
– arjacsoh, Commented Jul 25, 2012 at 7:35

OrangeDog · Accepted Answer · 2012-07-25 08:40:29Z

2

\b[^_]*?(_\d{3}.+?)?\b

A word (\b is word boundary, quantifiers are non-greedy). Zero or more characters that aren't _ ([^_]*?). Optionally ((...)?), the digit sequence you described (_\d{3}) followed by one or more of any character (.+?).

edited Jul 25, 2012 at 8:40

answered Jul 24, 2012 at 12:41

OrangeDog

39.3k18 gold badges141 silver badges227 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Besnik · Accepted Answer · 2012-07-24 14:17:10Z

0

Have you tried this:

static const wregex stringForm("([a-zA-Z0-9]*_[0-9]{3}.*)");

edited Jul 24, 2012 at 14:17

answered Jul 24, 2012 at 12:39

Besnik

6,5581 gold badge33 silver badges34 bronze badges

Collectives™ on Stack Overflow

Matching string using regex

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related