Search all php files for a string in between a class - php

Question

I am using a simple php translation class and I have about more than 2000 php files which the translation class was implemented and new strings are as well implemented so I need an updated text file with all the translation strings.
I need to get all the translated values from each php file and save it into a text file without any repeated value.
Translation class
<?php $translate->__('Calendar'); ?>
So I need to get Calendar saved into a txt file and this should be done for all the files in all folders.
Everything in between $translate->__(' and ') should be saved.
The below code not working for some reason.
$fn = $_SERVER['DOCUMENT_ROOT']."/apps/test/test2/calendar.php";
$handle = fopen($fn, 'r');
$valid = false;
$search = "\/\\$translate\\-\\>__\\(\\'(.*?)'\\)\/g";
while (($buffer = fgets($handle)) !== false) {
if(preg_match_all($search, $buffer, $m)) {
print $m[1];
} else {
}
}
fclose($handle);

Answer 1

You're extracting strings with this pattern:
/\$translate\-\>__\(\'(.*?)'\)/g
extract all of matched items and save them any where.
Demo and Details : https://regex101.com/r/LzMyJY/1
$fn = $_SERVER['DOCUMENT_ROOT']."/apps/test/test2/calendar.php";
$handle = fopen($fn, 'r');
$valid = false;
$search = "/\\".'$'."translate\\-\\>__\\(\\'(.*?)'\\)/g";
while (($buffer = fgets($handle)) !== false) {
if(preg_match_all($search, $buffer, $m)) {
print $m[1];
} else {
}
}
fclose($handle);
Note:
In use of regex patterns, remember handle backslash \ when putting pattern in ".." (change all \ to \\ in this case)
If using '...' don't change \ with \\ !