Post transfer info
Remember how libcurl transfers are associated with an "easy handle"! Each transfer has such a handle and when a transfer is completed, before the handle is cleaned or reused for another transfer, it can be used to extract information from the previous operation.
Your friend for doing this is called
curl_easy_getinfo() and you tell it which specific information you are interested in and it will return that to you if it can.When you use this function, you pass in the easy handle, which information you want and a pointer to a variable to hold the answer. You must pass in a pointer to a variable of the correct type or you risk that things will go side-ways. These information values are designed to be provided after the transfer is completed.
The data you receive can be a long, a 'char *', a 'struct curl_slist *', a double or a socket.
This is how you extract the
Content-Type: value from the previous HTTP transfer:CURLcode res;
char *content_type;
res = curl_easy_getinfo(curl, CURLINFO_CONTENT_TYPE, &content_type);
If you want to extract the local port number that was used in that connection:
CURLcode res;
long port_number;
res = curl_easy_getinfo(curl, CURLINFO_LOCAL_PORT, &port_number);
Getinfo option | Type | Description |
|---|---|---|
CURLINFO_ACTIVESOCKET | curl_socket_t | The session's active socket |
CURLINFO_APPCONNECT_TIME | double | Time from start until SSL/SSH handshake completed |
CURLINFO_APPCONNECT_TIME_T | curl_off_t | Time from start until SSL/SSH handshake completed (in microseconds) |
CURLINFO_CERTINFO | struct curl_slist * | Certificate chain |
CURLINFO_CONDITION_UNMET | long | Whether or not a time conditional was met |
CURLINFO_CONNECT_TIME | double | Time from start until remote host or proxy completed |
CURLINFO_CONNECT_TIME_T | curl_off_t | Time from start until remote host or proxy completed (in microseconds) |
CURLINFO_CONTENT_LENGTH_DOWNLOAD | double | Content length from the Content-Length header |
CURLINFO_CONTENT_LENGTH_UPLOAD | double | Upload size |
CURLINFO_CONTENT_TYPE | char * | Content type from the Content-Type header |
CURLINFO_COOKIELIST | struct curl_slist * | List of all known cookies |
CURLINFO_EFFECTIVE_METHOD | char * | Last used HTTP request method |
CURLINFO_EFFECTIVE_URL | char * | Last used URL |
CURLINFO_FILETIME | long | Remote time of the retrieved document |
CURLINFO_FTP_ENTRY_PATH | char * | The entry path after logging in to an FTP server |
CURLINFO_HEADER_SIZE | long | Number of bytes of all headers received |
CURLINFO_HTTP_CONNECTCODE | long | Last proxy CONNECT response code |
CURLINFO_HTTP_VERSION | long | The HTTP version used in the connection |
CURLINFO_HTTPAUTH_AVAIL | long | Available HTTP authentication methods (bitmask) |
CURLINFO_LASTSOCKET | long | Last socket used |
CURLINFO_LOCAL_IP | char * | Local-end IP address of last connection |
CURLINFO_LOCAL_PORT | long | Local-end port of last connection |
CURLINFO_NAMELOOKUP_TIME | double | Time from start until name resolving completed |
CURLINFO_NAMELOOKUP_TIME_T | curl_off_t | Time from start until name resolving completed (in microseconds) |
CURLINFO_NUM_CONNECTS | long | Number of new successful connections used for previous transfer |
CURLINFO_OS_ERRNO | long | The errno from the last failure to connect |
CURLINFO_PRETRANSFER_TIME | double | Time from start until just before the transfer begins |
CURLINFO_PRETRANSFER_TIME_T | curl_off_T | Time from start until just before the transfer begins (in microseconds) |
CURLINFO_PRIMARY_IP | char * | IP address of the last connection |
CURLINFO_PRIMARY_PORT | long | Port of the last connection |
CURLINFO_PRIVATE | char * | User's private data pointer |
CURLINFO_PROTOCOL | long | The protocol used for the connection |
CURLINFO_PROXY_ERROR | long | Detailed (SOCKS) proxy error if CURLE_PROXY was returned from the transfer |
CURLINFO_PROXY_SSL_VERIFYRESULT | long | Proxy certificate verification result |
CURLINFO_PROXYAUTH_AVAIL | long | Available HTTP proxy authentication methods |
CURLINFO_REDIRECT_COUNT | long | Total number of redirects that were followed |
CURLINFO_REDIRECT_TIME | double | Time taken for all redirect steps before the final transfer |
CURLINFO_REDIRECT_TIME_T | curl_off_t | Time taken for all redirect steps before the final transfer (in microseconds) |
CURLINFO_REDIRECT_URL | char * | URL a redirect would take you to, had you enabled redirects |
CURLINFO_REQUEST_SIZE | long | Number of bytes sent in the issued HTTP requests |
CURLINFO_RESPONSE_CODE | long | Last received response code |
CURLINFO_RETRY_AFTER | curl_off_t | The value from the response Retry-After: header |
CURLINFO_RTSP_CLIENT_CSEQ | long | RTSP CSeq that will next be used |
CURLINFO_RTSP_CSEQ_RECV | long | RTSP CSeq last received |
CURLINFO_RTSP_SERVER_CSEQ | long | RTSP CSeq that will next be expected |
CURLINFO_RTSP_SESSION_ID | char * | RTSP session ID |
CURLINFO_SCHEME | char * | The scheme used for the connection |
CURLINFO_SIZE_DOWNLOAD | double | Number of bytes downloaded |
CURLINFO_SIZE_UPLOAD | double | Number of bytes uploaded |
CURLINFO_SPEED_DOWNLOAD | double | Average download speed |
CURLINFO_SPEED_UPLOAD | double | Average upload speed |
CURLINFO_SSL_ENGINES | struct curl_slist * | A list of OpenSSL crypto engines |
CURLINFO_SSL_VERIFYRESULT | long | Certificate verification result |
CURLINFO_STARTTRANSFER_TIME | double | Time from start until just when the first byte is received |
CURLINFO_STARTTRANSFER_TIME_T | curl_off_t | Time from start until just when the first byte is received (in microseconds) |
CURLINFO_TLS_SSL_PTR | struct curl_slist * | TLS session info that can be used for further processing |
CURLINFO_TOTAL_TIME | double | Total time of previous transfer |
CURLINFO_TOTAL_TIME_T | curl_off_t | Total time of previous transfer (in microseconds) |
Last modified 1yr ago