PHP searching for a string in a file

Question

I'm looking for a function that counts the number of times a string occurs within a file, I tried using $count = preg_match_all("/String/", $file, $matches); but it returns Warning: preg_match_all() expects parameter 2 to be string, resource given. Is there any function that allows me to do this with a file, instead of a string, or is there any way to assign a file to a string (I assume the latter would be a lot slower)?

Answer 1

yes:

file_get_contents() — Reads entire file into a string

http://php.net/manual/en/function.file-get-contents.php

so for you it would be

$file = file_get_contents(PATH_TO_FILE);
$count = preg_match_all("/String/", $file, $matches);

I'm guessing you have used fopen instead by mistake?

Answer 2

$count = substr_count(file_get_contents($file), $string);

Manual:
substr_count
file_get_contents