Reading and writing large arrays to and from .txt files - php

Question

I'm trying to execute the code below and I keep on getting a message reading killed when I load the file in my terminal. I'm aware that I'm using lots of memory, so I set the memory limit to the maximum amount allowed on apache. I have a text file called codes.txt that contains a list of numbers from 0 to 1000000. I need to randomize the occurrence of these numbers and then write the new order of them to a new text file. Then, I need to store the new occurrence of them in an array.
ini_set('memory_limit', '2048M');
// Get all of the values from the .txt file
// and store them in an array
$file = fopen("codes.txt", "r");
$codes = array();
while(!feof($file)) {
$codes[] = trim(fgets($file));
}
fclose($file);
// Randomize the elements in the array
shuffle($codes);
// Write each element in the shuffled array to a new .txt file
$new_file = fopen("new_codes.txt", "w");
for($i=0;$i<1000000;$i++) {
fwrite($new_file, $codes[$i].PHP_EOL);
}
fclose($new_file);
// Put all of the new elements into a new array
$new_file = fopen("new_codes.txt", "r");
$code = array();
while(!feof($new_file)) {
$code[] = trim(fgets($new_file));
}
print_r($code);

Answer 1

Don't worry about a new array, $codes already has them. If you need to close, reopen the file and read them into a new array, and memory is the issue, then kill the old array first by using unset($codes) before opening the file.
ini_set('memory_limit', '2048M');
// Get all of the values from the .txt file
// and store them in an array
$file = fopen("codes.txt", "r");
$codes = array();
while (!feof($file)) {
$codes[] = trim(fgets($file));
}
fclose($file);
// Randomize the elements in the array
shuffle($codes);
// Write each element in the shuffled array to a new .txt file
$new_file = fopen("new_codes.txt", "w");
foreach($codes as $k => $v){
fwrite($new_file, $v.PHP_EOL);
}
fclose($new_file);