Executing the PHP/CURL command sets into action all the options defined with the curl_setopt() function. This command executes the previously configured session (referenced by $s in Listing A-18).
$downloaded_page = curl_exec($s);
Listing A-18: Executing a PHP/CURL command for session $s
You can execute the same command multiple times or use curl_setopt() to change configurations between calls of curl_exec(), as long as the session is defined and hasn't been closed. Typically, I create a new PHP/CURL session for every page I access.
Additional information about the current PHP/CURL session is available once a curl_exec() command is executed. Listing A-19 shows how to use this command.
$info_array = curl_getinfo($s);
Listing A-19: Getting additional information about the current PHP/CURL session
The curl_getinfo() command returns an array of information, including connect and transfer times, as shown in Listing A-20.
array(20)
{
["url"]=> string(22) "http://www.schrenk.com"
["content_type"]=> string(29) "text/html; charset=ISO-8859-1"
["http_code"]=> int(200) ["header_size"]=> int(247)
["request_size"]=> int(125)
["filetime"]=> int(-1)
["ssl_verify_result"]=> int(0)
["redirect_count"]=> int(0)
["total_time"]=> float(0.884)
["namelookup_time"]=> float(0)
["connect_time"]=> float(0.079)
["pretransfer_time"]=> float(0.079)
["size_upload"]=> float(0)
["size_download"]=> float(19892)
["speed_download"]=> float(22502.2624434)
["speed_upload"]=> float(0)
["download_content_length"]=> float(0)
["upload_content_length"]=> float(0)
["starttransfer_time"]=> float(0.608)
["redirect_time"]=> float(0)
}
Listing A-20: Data made available by the curl_getinfo() command
The curl_error() function returns any errors that may have occurred during a PHP/CURL session. The usage for this function is shown in Listing A-21.
$errors = curl_error($s);
Listing A-21: Accessing PHP/CURL session errors
A typical error response is shown in Listing A-22.
Couldn't resolve host 'www.webbotworld.com'
Listing A-22: Typical PHP/CURL session error