如果文件超过10 mb +,PHP TXT文件搜索器崩溃

I got an answer earlier today which can be found here: Searching multiple strings in one txt file

I got a good answer, but there seems to be one last issue with it. When I am searching a file which exceeds 10 mb it doesn't show any more results.

This code allows me to search multiple strings. Which is what I want.

The code:

<?php 
$search1 = "value 1"; 
$search2 = "value 2";

$lines = file('my_file.txt'); 

foreach($lines as $line) 
{ 
    if(stristr($line,$search1) || stristr($line,$search2))

        echo " $line <br>"; 
} 
?>

I would have no clue. I had code which could only search one string but it could go over 10 mb+ files. But now I want to search multiple strings and that is why I have this issue now.

The script which works over 10 mb+, this is the one I used earlier before I got the code above - But can only search one string, but I want to search multiple strings at once.

$search = $_GET["search"]; 
$search2 = $_GET['search2'];
$logfile = $_GET['logfile'];


// Read from file 
$file = fopen($logfile, "r");?> 
<head><title>Searching: <?php echo $search ?></title></head>
<?php
while( ($line =  fgets($file) && $line2 = fgets($file))!= false)
{   if (stristr($line, $search)) { } if (stristr($line2, $search2)) { }  

?><font face='Arial'> <?php $lines = $line + line2; ?><?php echo $lines ?></font><hr><p><?php
}

Thank you for reading.