How to make fputcsv "echo" the data

As the original asker wanted to "write to the browser on the fly", maybe is worth noting (as was my case and noone mentioned it) that if you want to force a file name and a dialog asking to download a file in the browser, you must set the proper headers before outputting anything with fputcsv:

header('Content-Type: text/csv; charset=utf-8');
header('Content-Disposition: attachment; filename=myFile.csv');

By a comment on the PHP site

<?php
$out = fopen('php://output', 'w');
fputcsv($out, array('this','is some', 'csv "stuff", you know.'));
fclose($out);
?>

Found this on the PHP docs website, first comment under the function reference:

function outputCSV($data) {
  $outstream = fopen("php://output", 'w');
  function __outputCSV(&$vals, $key, $filehandler) {
    fputcsv($filehandler, $vals, ';', '"');
  }
  array_walk($data, '__outputCSV', $outstream);
  fclose($outstream);
}

And a second option:

$csv = fopen('php://temp/maxmemory:'. (5*1024*1024), 'r+');
fputcsv($csv, array('blah','blah'));
rewind($csv);

// put it all in a variable
$output = stream_get_contents($csv);

Hope this helps!

BTW the PHP docs should always be your first stop when trying to figure things out. :-)