[php] Creating csv file with php

I want to create a csv file, but when I run the code, it returns a blank page and no csv file. I use PHP 5. I use the following code:

<?php
    $data = array ('aaa,bbb,ccc,dddd',
                   '123,456,789',
                   '"aaa","bbb"');

    $fp = fopen('data.csv', 'w');
    foreach($data as $line){
             $val = explode(",",$line);
             fputcsv($fp, $val);
    }
    fclose($fp);
?>

Thank you!

Just in case if someone is wondering to save the CSV file to a specific path for email attachments. Then it can be done as follows

I know I have added a lot of comments just for newbies :)

I have added an example so that you can summarize well.

$activeUsers = /** Query to get the active users */

/** Following is the Variable to store the Users data as 
    CSV string with newline character delimiter, 

    its good idea of check the delimiter based on operating system */

$userCSVData = "Name,Email,CreatedAt\n";

/** Looping the users and appending to my earlier csv data variable */
foreach ( $activeUsers as $user ) {
    $userCSVData .= $user->name. "," . $user->email. "," . $user->created_at."\n";
}
/** Here you can use with H:i:s too. But I really dont care of my old file  */
$todayDate  = date('Y-m-d');
/** Create Filname and Path to Store */
$fileName   = 'Active Users '.$todayDate.'.csv';
$filePath   = public_path('uploads/'.$fileName); //I am using laravel helper, in case if your not using laravel then just add absolute or relative path as per your requirements and path to store the file

/** Just in case if I run the script multiple time 
    I want to remove the old file and add new file.

    And before deleting the file from the location I am making sure it exists */
if(file_exists($filePath)){
    unlink($filePath);
}
$fp = fopen($filePath, 'w+');
fwrite($fp, $userCSVData); /** Once the data is written it will be saved in the path given */
fclose($fp);

/** Now you can send email with attachments from the $filePath */

NOTE: The following is a very bad idea to increase the memory_limit and time limit, but I have only added to make sure if anyone faces the problem of connection time out or any other. Make sure to find out some alternative before sticking to it.

You have to add the following at the start of the above script.

ini_set("memory_limit", "10056M");
set_time_limit(0);
ini_set('mysql.connect_timeout', '0');
ini_set('max_execution_time', '0');

@Baba's answer is great. But you don't need to use explode because fputcsv takes an array as a parameter

For instance, if you have a three columns, four lines document, here's a more straight version:

header('Content-Type: text/csv');
header('Content-Disposition: attachment; filename="sample.csv"');

$user_CSV[0] = array('first_name', 'last_name', 'age');

// very simple to increment with i++ if looping through a database result 
$user_CSV[1] = array('Quentin', 'Del Viento', 34);
$user_CSV[2] = array('Antoine', 'Del Torro', 55);
$user_CSV[3] = array('Arthur', 'Vincente', 15);

$fp = fopen('php://output', 'wb');
foreach ($user_CSV as $line) {
    // though CSV stands for "comma separated value"
    // in many countries (including France) separator is ";"
    fputcsv($fp, $line, ',');
}
fclose($fp);