按部分划分循环

I have a large text file around 25k lines... I need to divide them into 2000 and put those each 2000 into text file...code i have so far.

<?php

$lines = file("largefile.txt", FILE_IGNORE_NEW_LINES);

$i = 1;
foreach($lines as $lol)
{

//now i need to put first 2000 lines in 1.txt and then next 2000 lines in 2.txt
file_put_contents($i".txt", $lol . PHP_EOL, FILE_APPEND)

}

?>

now i need to put first 2000 lines in 1.txt and then next 2000 lines in 2.txt and so on..

I think you can loop in your lines array and count your loop, so you can change filename according with your total required lines as follow

$i=1;
$o=0;
for($u=0;$u<count($lines);$u++)
{
    if($o<2000)
    {
         file_put_contents($i".txt", $lines[$u] . PHP_EOL, FILE_APPEND);
         $o++;
    } else {
        $i++;
        file_put_contents($i".txt", $lines[$u] . PHP_EOL, FILE_APPEND);           
        $o=1;
    }            
}

Thanks. I think you can use the linux command split like this.

<?php
    exec("split largefile.txt -l 2000");
?>