Read big file csv

bigfile.php

function file_get_contents_chunked($file,$chunk_size,$callback)
{
    try
    {
        $handle = fopen($file, "r");
        $i = 0;
        while (!feof($handle))
        {
            call_user_func_array($callback,array(fread($handle,$chunk_size),&$handle,$i));
            $i++;
        }

        fclose($handle);

    }
    catch(Exception $e)
    {
         trigger_error("file_get_contents_chunked::" . $e->getMessage(),E_USER_NOTICE);
         return false;
    }

    return true;
}

$success = file_get_contents_chunked("my/large/file",4096,function($chunk,&$handle,$iteration){
    /*
        * Do what you will with the {&chunk} here
        * {$handle} is passed in case you want to seek
        ** to different parts of the file
        * {$iteration} is the section fo the file that has been read so
        * ($i * 4096) is your current offset within the file.
    */

});

if(!$success)
{
    //It Failed
}

https://stackoverflow.com/questions/5249279/file-get-contents-php-fatal-error-allowed-memory-exhausted/5249971#5249971