Buffering passthru() to allow headers?

robertaccettura

I've got an interesting situation.

I need to run a perl script from within a php application... that's pretty simple

<?PHP passthru('script.cgi'); ?>

Now here is the problem. The script generates a header or two (cookies actually). But since the PHP before the execution sends html... the headers aren't set correctly, they are displayed as text on the page.

So my question is (if you haven't guessed already).

How can output buffering be used to allow the headers to be sent (including those from the perl script) ... then the data (PHP, and perl script's)?

rewriting the script isn't an option. I'm limited to the PHP itself.

mtmosier

Sounds like you need the output control functions.

robertaccettura

Yes, and that's stated within the question :p

The question I have is how to make it work.

You can just wrap

  ob_start();
  ob_end_flush();

around it...

and it doesn't nothing beneficial. You'll still see:

Set-Cookie: foo=bar;

in the page.

mtmosier

Well, is this cgi script outputing binary data, or can you skip the passthru and do exec instead?

You can buffer the php output until you get to the cgi script, capture the output of that, parse out the headers and use the php header function to set them, then echo out the remainder of the cgi script output. The only issue I see there is binary data coming out of the cgi, and only then because I don't know if the output control functions and/or exec are binary safe.

I suppose popen is an option if it is binary data.

mtmosier

function execCGI($command) {
    $pipe = popen($command, 'r');
    if (!$pipe) {
        return false;
    }
    $data = '';
    while (!feof($pipe)) {
        $data .= fread($pipe, 2048);
    }
    pclose($pipe);

$pos = strpos($data, "\r\n\r\n");
if ($pos !== false) {
    $headers = explode("\r\n", substr($data, 0, $pos));
    foreach ($headers as $header) {
        if (strtolower(substr($header, 0, 7)) != 'status:') {
            header($header);
        }
    }

    $data = substr($data, $pos + 4);
}

return $data;
}

Tested with cgis returning html as well jpegs. The header section could probably use some tweaking.