I'd like to see what the post fields in the request are before I send it. (For debugging purposes).
The PHP library (class) I am using is already made (not by me), so I am trying to understand it.
As far as I can tell, it uses curl_setopt() to set different options like headers and such and then it uses curl_exec() to send the request.
Ideas on how to see what post fields are being sent?
Answer
You can enable the CURLOPT_VERBOSE option and log that information to a (temporary) CURLOPT_STDERR:
// CURLOPT_VERBOSE: TRUE to output verbose information. Writes output to STDERR,
// or the file specified using CURLOPT_STDERR.
curl_setopt($handle, CURLOPT_VERBOSE, true);
$verbose = fopen('php://temp', 'w+');
curl_setopt($handle, CURLOPT_STDERR, $verbose);
You can then read it after curl has done the request:
$result = curl_exec($handle);
if ($result === FALSE) {
printf("cUrl error (#%d): %s<br>\n", curl_errno($handle),
htmlspecialchars(curl_error($handle)));
}
rewind($verbose);
$verboseLog = stream_get_contents($verbose);
echo "Verbose information:\n<pre>", htmlspecialchars($verboseLog), "</pre>\n";
(I originally answered similar but more extended in a related question.)
More information like metrics about the last request is available via curl_getinfo. This information can be useful for debugging curl requests, too. A usage example, I would normally wrap that into a function:
$version = curl_version();
extract(curl_getinfo($handle));
$metrics = <<<EOD
URL....: $url
Code...: $http_code ($redirect_count redirect(s) in $redirect_time secs)
Content: $content_type Size: $download_content_length (Own: $size_download) Filetime: $filetime
Time...: $total_time Start @ $starttransfer_time (DNS: $namelookup_time Connect: $connect_time Request: $pretransfer_time)
Speed..: Down: $speed_download (avg.) Up: $speed_upload (avg.)
Curl...: v{$version['version']}
EOD;