在PHP中搜索非空白正确的字符串

Question

I'm have a project where I need to find occurrences of a string in a large body of text. The search string is known to be present in the larger text, however for reasons beyond my control they are not white-space correct, in that they are missing spaces between some of the words.

For example I the string to find is (not the lack of space between brown and fox:

quick brownfox jumps

And I need to find this in:

The quick brown fox jumps over the lazy dog.

I need to be able to modify the haystack to wrap the found terms with an identifying tag so I'll end up with something like:

The <span class="found">quick brown fox jumps</span> over the lazy dog.

I've looked into using regex in free-spacing mode which seems to not quite do what I need, I considered stripping all white space from the search terms and adding \s* between each character but thought this might have a horrendous effect on performance (can any regex experts could confirm or deny that?).

Are there any possible non-regex solutions to look into.

Thanks

Answer 1

The best way in this case would be to remove all the whitespaces in the search string, and the target string. And then check if the string is present or not:

$haystack = 'The quick brown fox jumps over the lazy dog.';
$needle = 'quick brownfox jumps';

$haystack = preg_replace("\s+", "", $haystack);
$needle = preg_replace("\s+", "", $needle);

if (strpos($haystack, $needle) !== false) {
    echo 'true';
}