PHP efficiently write and output csv files using fputcsv - php

Question

When writing .csv files i use fputcsv like this:
- open a temporary file $f = tmpfile();
- write content to file using fputcsv($f,$csv_row);
- send appropriate headers for attachment
- read file like this:
# move pointer back to beginning
rewind($f);
while(!feof($f))
echo fgets($f);
# fclose deletes temp file !
fclose($f);
Another aproach would be:
- open file $f = fopen('php://output', 'w');
- send appropriate headers for attachment
- write content to file using fputcsv($f,$csv_row);
- close $f stream
My question is: What would be the best approach to output the data faster and taking into account server resources ?
First method would use more writes and consume more resources but would output very fast.
Second method uses less writes and would output slower i think.
Eagerly waiting for your opinions on this.
Thanks.

Answer 1

fpassthru() will do what you're doing at a lower level. Use it like this:
# move pointer back to beginning
rewind($f);
while(fpassthru($f) !== false);
# fclose deletes temp file !
fclose($f);
Even though it may be a csv file, there is no need to restrict yourself to csv functions, unless you are generating the file at the time of output.
You could probably see a performance gain if you stream the CSV to output instead of to a file.

Answer 2

Why do you need to write the csv content to a tmp file/php's output stream ?
You just need to echo the csv content directly, there should not be any file operations.
send appropriate headers for attachment
echo the csv content.
header("Content-type: application/csv");
header("Content-Disposition: attachment; filename=file.csv");
header("Pragma: no-cache");
header("Expires: 0");
foreach ($csv_rows as $csv_row) {
echo $csv_row;
}
exit;