Converting a single column from a CSV in to a simple array using PHP

Question

I've got a csv with a list of emails in a single column with no header.

Very simply, they're like this:

example@123.com
email@somewhere.com
helloworld@email.org

...etc

And there are 30k of them.

I need to convert this list of emails in to a simple array using PHP.

I understand the concept of fgetcsv() but as we know it reads a row at a time, so what I end up with is several arrays by iterating through my csv instead of one.

I need this:

Array
(
    [0] => example@123.com
    [1] => email@somewhere.com
    [2] => helloworld@email.org
)

What I'm getting is this:

Array
(
    [0] => example@123.com
)

Array
(
    [0] => email@somewhere.com
)

Array
(
    [0] => helloworld@email.org
)

Here's my code:

if (($file = fopen("emails.csv", "r")) !== FALSE) {
    while (($data = fgetcsv($file)) !== FALSE) {
          // do stuff
    }

    echo '<pre>';
    print_r($data);
    echo '</pre>';
    echo '<br/>';   

    fclose($file);  
}

Is there a simple way of simply converting a whole CSV column in to an array using PHP? I've been doing my research but have yet to find a solution.

Answer 1

If you have only one column in your file, you really don't need to use fgetcsv. You could use the fgets function (http://us2.php.net/manual/en/function.fgets.php) instead. This function returns a string, which you could easily add to your array like so:

$emails = array();
if (($file = fopen("emails.csv", "r")) !== FALSE) {
    while (($email = fgets($file)) !== FALSE) {
         $emails[] = $email;
    }
    fclose($file);  
}

Alternatively, if you insist upon using fgetcsv, you could alter your code as follows:

$emails = array();
if (($file = fopen("emails.csv", "r")) !== FALSE) {
    while (($arr = fgetcsv($file)) !== FALSE) {
         $emails[] = $arr[0];
    }
    fclose($file);  
}

Finally, I have read, but not tested myself, that the stream_get_line function (http://www.php.net/manual/en/function.stream-get-line.php) is even faster than fgets. You could substitute it above.

Answer 2

Why don't you use SplFileObject? I've done some benchmarking in the past and it's around 2 times faster than fgetcsv

Here is a sample code:

/**
 * Get the CSV file as a SplFileObject so we could easily process it afterwards.
 */
$file = '/path/to/my/file.csv';     
$delimiter = ',';
$csv_file = new SplFileObject($file);
$csv_file->setFlags(SplFileObject::SKIP_EMPTY | SplFileObject::DROP_NEW_LINE);
$csv_file->setCsvControl($delimiter);

/**
 * Process each line from the CSV file
 */
while ($csv_file->current() !== false) {
    $count++;
    $lines[] = trim($csv_file->current());
    $csv_file->next();
}

var_dump($lines);

?>

Also, since your file contains only one column, you could just use file to retrieve the file content as an array. (http://www.php.net/manual/en/function.file.php)

// Get a file into an array.  In this example we'll go through HTTP to get
// the HTML source of a URL.
$lines = file('/path/to/file.csv', FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);