Regexp match all pieces of a string with `[0-9_]+` and skip optional `_[a-z0-9]{24}`?

Question

Regexp match all pieces of a string with [0-9_]+ and skip optional _[a-z0-9]{24} ?

For instance,

hello word some_stuff other_stuff_607eea770b6d00003d001579 something

Should only capture/match

hello word some_stuff other_stuff something

Here's what I have but it still matches some part of [a-z0-9]{24}

/[a-z]+(_[a-z]+)?(?:[a-z0-9]{24})?/

Grismar · Accepted Answer · 2021-10-18T00:40:20.353

1

You're looking to match strings consisting of letters and underscores, whole words, with the end of the word at the end of the string, or a sequence of 24 more letters and/or numbers preceded by an underscore:

\b[a-z_]+(?=_[0-9a-z]{24}|\b)

edited Oct 18 '21 at 00:40

answered Oct 18 '21 at 00:34

Grismar

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Yep, that works!! Will validate when it let me... – Eric Oct 18 '21 at 00:35
1

Actually, no - I failed to notice you also want to match the starting bit of other_stuff_etc – Grismar Oct 18 '21 at 00:35
Ah yea you're right, got too excited lmao – Eric Oct 18 '21 at 00:36
1

Fixed it - bit more complicated, but still quite straightforward, assuming your engine supports lookahead – Grismar Oct 18 '21 at 00:40

score 1 · Answer 2 · answered Oct 18 '21 at 09:11

As you mention php in the comment of the accepted answer, you might also make use of a SKIP FAIL approach:

_[0-9a-z]{24}(*SKIP)(*FAIL)|[a-z]+(?:_[a-z]+)*

In parts, the pattern matches:

_[0-9a-z]{24} Match _ and 24 repetitions of ranges 0-9a-z
(*SKIP)(*FAIL) The previous matched should not be part of the match result
| or
[a-z]+ Match 1+ chars a-z
(?:_[a-z]+)* Optionally repeat _ and 1+ chars a-z

See a regex demo and a PHP demo

Example code

$re = '/_[0-9a-z]{24}(*SKIP)(*FAIL)|[a-z]+(?:_[a-z]+)*/';
$str = 'hello word some_stuff other_stuff_607eea770b6d00003d001579 something';

preg_match_all($re, $str, $matches);

var_export($matches[0]);

Output

array (
  0 => 'hello',
  1 => 'word',
  2 => 'some_stuff',
  3 => 'other_stuff',
  4 => 'something',
)

Interesting, I didn't know about skip/fail, thanks for reply, upvoted. — Eric, Oct 18 '21 at 13:07

Regexp match all pieces of a string with `[0-9_]+` and skip optional `_[a-z0-9]{24}`?

2 Answers2