PHP HTTP内容范围混乱[重复]

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Uses of content-disposition in an HTTP response header 6 answers

Im looking at a snippet i found on the internet but im not sure what one part of the script does.

// parse the Content-Disposition header, if available:
$file_name = $this->getServerVar('HTTP_CONTENT_DISPOSITION') ?
rawurldecode(preg_replace('/(^[^"]+")|("$)/', '', $this->getServerVar('HTTP_CONTENT_DISPOSITION'))) : null;


protected function getServerVar($id)
{
    return isset($_SERVER[$id]) ? $_SERVER[$id] : '';
}

I tried to print this "print_r($this->getServerVar('HTTP_CONTENT_RANGE') ?"

But i get nothing.

Could someone provide in depth information on what exactly HTTP_CONTENT_DISPOSITION is and what is happening in the above code

Also does what does HTTP_CONTENT_RANGE mean?

Thanks!!!

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I would have left this as a comment if I had enough creds. But here is a link you might find helpful

Uses of content-disposition in an HTTP response header