curl/docs/libcurl/curl_easy_getinfo.3

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.TH curl_easy_getinfo 3 "11 Feb 2009" "libcurl 7.19.4" "libcurl Manual"
.SH NAME
curl_easy_getinfo - extract information from a curl handle
.SH SYNOPSIS
.B #include <curl/curl.h>

.B "CURLcode curl_easy_getinfo(CURL *curl, CURLINFO info, ... );"

.SH DESCRIPTION
Request internal information from the curl session with this function.  The
third argument \fBMUST\fP be a pointer to a long, a pointer to a char *, a
pointer to a struct curl_slist * or a pointer to a double (as this
documentation describes further down).  The data pointed-to will be filled in
accordingly and can be relied upon only if the function returns CURLE_OK.  Use
this function AFTER a performed transfer if you want to get transfer related
data.

You should not free the memory returned by this function unless it is
explicitly mentioned below.
.SH AVAILABLE INFORMATION
The following information can be extracted:
.IP CURLINFO_EFFECTIVE_URL
See \fICURLINFO_EFFECTIVE_URL(3)\fP
.IP CURLINFO_RESPONSE_CODE
See \fICURLINFO_RESPONSE_CODE(3)\fP
.IP CURLINFO_HTTP_CONNECTCODE
See \fICURLINFO_HTTP_CONNECTCODE(3)\fP
.IP CURLINFO_FILETIME
See \fICURLINFO_FILETIME(3)\fP
.IP CURLINFO_TOTAL_TIME
See \fICURLINFO_TOTAL_TIME(3)\fP
.IP CURLINFO_NAMELOOKUP_TIME
See \fICURLINFO_NAMELOOKUP_TIME(3)\fP
.IP CURLINFO_CONNECT_TIME
See \fICURLINFO_CONNECT_TIME(3)\fP
.IP CURLINFO_APPCONNECT_TIME
See \fICURLINFO_APPCONNECT_TIME(3)\fP
.IP CURLINFO_PRETRANSFER_TIME
See \fICURLINFO_PRETRANSFER_TIME(3)\fP
.IP CURLINFO_STARTTRANSFER_TIME
See \fICURLINFO_STARTTRANSFER_TIME(3)\fP
.IP CURLINFO_REDIRECT_TIME
See \fICURLINFO_REDIRECT_TIME(3)\fP
.IP CURLINFO_REDIRECT_COUNT
See \fICURLINFO_REDIRECT_COUNT(3)\fP
.IP CURLINFO_REDIRECT_URL
See \fICURLINFO_REDIRECT_URL(3)\fP
.IP CURLINFO_SIZE_UPLOAD
See \fICURLINFO_SIZE_UPLOAD(3)\fP
.IP CURLINFO_SIZE_DOWNLOAD
See \fICURLINFO_SIZE_DOWNLOAD(3)\fP
.IP CURLINFO_SPEED_DOWNLOAD
See \fICURLINFO_SPEED_DOWNLOAD(3)\fP
.IP CURLINFO_SPEED_UPLOAD
See \fICURLINFO_SPEED_UPLOAD(3)\fP
.IP CURLINFO_HEADER_SIZE
Pass a pointer to a long to receive the total size of all the headers
received. Measured in number of bytes.
.IP CURLINFO_REQUEST_SIZE
Pass a pointer to a long to receive the total size of the issued
requests. This is so far only for HTTP requests. Note that this may be more
than one request if FOLLOWLOCATION is true.
.IP CURLINFO_SSL_VERIFYRESULT
Pass a pointer to a long to receive the result of the certification
verification that was requested (using the \fICURLOPT_SSL_VERIFYPEER(3)\fP
option to \fIcurl_easy_setopt(3)\fP).
.IP CURLINFO_SSL_ENGINES
Pass the address of a 'struct curl_slist *' to receive a linked-list of
OpenSSL crypto-engines supported. Note that engines are normally implemented
in separate dynamic libraries. Hence not all the returned engines may be
available at run-time. \fBNOTE:\fP you must call \fIcurl_slist_free_all(3)\fP
on the list pointer once you're done with it, as libcurl will not free the
data for you. (Added in 7.12.3)
.IP CURLINFO_CONTENT_LENGTH_DOWNLOAD
Pass a pointer to a double to receive the content-length of the download. This
is the value read from the Content-Length: field. Since 7.19.4, this returns -1
if the size isn't known.
.IP CURLINFO_CONTENT_LENGTH_UPLOAD
Pass a pointer to a double to receive the specified size of the upload.  Since
7.19.4, this returns -1 if the size isn't known.
.IP CURLINFO_CONTENT_TYPE
Pass a pointer to a char pointer to receive the content-type of the downloaded
object. This is the value read from the Content-Type: field. If you get NULL,
it means that the server didn't send a valid Content-Type header or that the
protocol used doesn't support this.
.IP CURLINFO_PRIVATE
Pass a pointer to a char pointer to receive the pointer to the private data
associated with the curl handle (set with the \fICURLOPT_PRIVATE(3)\fP option
to \fIcurl_easy_setopt(3)\fP). Please note that for internal reasons, the
value is returned as a char pointer, although effectively being a 'void *'.
(Added in 7.10.3)
.IP CURLINFO_HTTPAUTH_AVAIL
Pass a pointer to a long to receive a bitmask indicating the authentication
method(s) available. The meaning of the bits is explained in the
\fICURLOPT_HTTPAUTH(3)\fP option for \fIcurl_easy_setopt(3)\fP.  (Added in
7.10.8)
.IP CURLINFO_PROXYAUTH_AVAIL
Pass a pointer to a long to receive a bitmask indicating the authentication
method(s) available for your proxy authentication.  (Added in 7.10.8)
.IP CURLINFO_OS_ERRNO
Pass a pointer to a long to receive the errno variable from a connect failure.
Note that the value is only set on failure, it is not reset upon a
successful operation.  (Added in 7.12.2)
.IP CURLINFO_NUM_CONNECTS
Pass a pointer to a long to receive how many new connections libcurl had to
create to achieve the previous transfer (only the successful connects are
counted).  Combined with \fICURLINFO_REDIRECT_COUNT\fP you are able to know
how many times libcurl successfully reused existing connection(s) or not.  See
the Connection Options of \fIcurl_easy_setopt(3)\fP to see how libcurl tries
to make persistent connections to save time.  (Added in 7.12.3)
.IP CURLINFO_PRIMARY_IP
Pass a pointer to a char pointer to receive the pointer to a zero-terminated
string holding the IP address of the most recent connection done with this
\fBcurl\fP handle. This string may be IPv6 if that's enabled. Note that you
get a pointer to a memory area that will be re-used at next request so you
need to copy the string if you want to keep the information. (Added in 7.19.0)
.IP CURLINFO_PRIMARY_PORT
Pass a pointer to a long to receive the destination port of the most recent
connection done with this \fBcurl\fP handle. (Added in 7.21.0)
.IP CURLINFO_LOCAL_IP
Pass a pointer to a char pointer to receive the pointer to a zero-terminated
string holding the local (source) IP address of the most recent connection done
with this \fBcurl\fP handle. This string may be IPv6 if that's enabled. The
same restrictions apply as to \fICURLINFO_PRIMARY_IP\fP. (Added in 7.21.0)
.IP CURLINFO_LOCAL_PORT
Pass a pointer to a long to receive the local (source) port of the most recent
connection done with this \fBcurl\fP handle. (Added in 7.21.0)
.IP CURLINFO_COOKIELIST
Pass a pointer to a 'struct curl_slist *' to receive a linked-list of all
cookies cURL knows (expired ones, too). Don't forget to
\fIcurl_slist_free_all(3)\fP the list after it has been used.  If there are no
cookies (cookies for the handle have not been enabled or simply none have been
received) 'struct curl_slist *' will be set to point to NULL. (Added in
7.14.1)
.IP CURLINFO_LASTSOCKET
Pass a pointer to a long to receive the last socket used by this curl
session. If the socket is no longer valid, -1 is returned. When you finish
working with the socket, you must call curl_easy_cleanup() as usual and let
libcurl close the socket and cleanup other resources associated with the
handle. This is typically used in combination with
\fICURLOPT_CONNECT_ONLY(3)\fP.  (Added in 7.15.2)

NOTE: this API is deprecated since it is not working on win64 where the SOCKET
type is 64 bits large while its 'long' is 32 bits. Use the
\fICURLINFO_ACTIVESOCKET\fP instead, if possible.
.IP CURLINFO_ACTIVESOCKET
Pass a pointer to a curl_socket_t to receive the active socket used by this
curl session. If the socket is no longer valid, -1 is returned. When you
finish working with the socket, you must call curl_easy_cleanup() as usual and
let libcurl close the socket and cleanup other resources associated with the
handle. This is typically used in combination with
\fICURLOPT_CONNECT_ONLY(3)\fP.

NOTE: this is meant as a cross-platform, safe alternative to
\fICURLINFO_LASTSOCKET\fP, which does not work on win64.
.IP CURLINFO_FTP_ENTRY_PATH
Pass a pointer to a char pointer to receive a pointer to a string holding the
path of the entry path. That is the initial path libcurl ended up in when
logging on to the remote FTP server. This stores a NULL as pointer if
something is wrong. (Added in 7.15.4)

Also works for SFTP since 7.21.4
.IP CURLINFO_CERTINFO
Pass a pointer to a 'struct curl_certinfo *' and you'll get it set to point to
struct that holds a number of linked lists with info about the certificate
chain, assuming you had \fICURLOPT_CERTINFO(3)\fP enabled when the previous
request was done. The struct reports how many certs it found and then you can
extract info for each of those certs by following the linked lists. The info
chain is provided in a series of data in the format "name:content" where the
content is for the specific named data. See also the certinfo.c example. NOTE:
this option is only available in libcurl built with OpenSSL, NSS or GSKit
support. (Added in 7.19.1)
.IP CURLINFO_TLS_SESSION
Pass a pointer to a 'struct curl_tlssessioninfo *'.  The pointer will be
initialized to refer to a 'struct curl_tlssessioninfo *' that will contain an
enum indicating the SSL library used for the handshake and the respective
internal TLS session structure of this underlying SSL library.

This may then be used to extract certificate information in a format
convenient for further processing, such as manual validation. NOTE: this
option may not be available for all SSL backends; unsupported SSL backends
will return 'CURLSSLBACKEND_NONE' to indicate that they are not supported;
this does not mean that no SSL backend was used. (Added in 7.34.0)

.nf
struct curl_tlssessioninfo {
  curl_sslbackend backend;
  void *internals;
};
.fi

The \fIinternals\fP struct member will point to a TLS library specific pointer
with the following underlying types:
.RS
.IP OpenSSL
SSL_CTX *
.IP GnuTLS
gnutls_session_t
.IP NSS
PRFileDesc *
.IP gskit
gsk_handle
.RE

.IP CURLINFO_CONDITION_UNMET
Pass a pointer to a long to receive the number 1 if the condition provided in
the previous request didn't match (see \fICURLOPT_TIMECONDITION(3)\fP). Alas,
if this returns a 1 you know that the reason you didn't get data in return is
because it didn't fulfill the condition. The long ths argument points to will
get a zero stored if the condition instead was met. (Added in 7.19.4)
.IP CURLINFO_RTSP_SESSION_ID
Pass a pointer to a char pointer to receive a pointer to a string holding the
most recent RTSP Session ID.

Applications wishing to resume an RTSP session on another connection should
retrieve this info before closing the active connection.
.IP CURLINFO_RTSP_CLIENT_CSEQ
Pass a pointer to a long to receive the next CSeq that will be used by the
application.
.IP CURLINFO_RTSP_SERVER_CSEQ
Pass a pointer to a long to receive the next server CSeq that will be expected
by the application.

\fI(NOTE: listening for server initiated requests is currently
unimplemented).\fP

Applications wishing to resume an RTSP session on another connection should
retrieve this info before closing the active connection.
.IP CURLINFO_RTSP_CSEQ_RECV
Pass a pointer to a long to receive the most recently received CSeq from the
server. If your application encounters a \fICURLE_RTSP_CSEQ_ERROR\fP then you
may wish to troubleshoot and/or fix the CSeq mismatch by peeking at this value.
.SH TIMES
.nf
An overview of the six time values available from curl_easy_getinfo()

curl_easy_perform()
    |
    |--NAMELOOKUP
    |--|--CONNECT
    |--|--|--APPCONNECT
    |--|--|--|--PRETRANSFER
    |--|--|--|--|--STARTTRANSFER
    |--|--|--|--|--|--TOTAL
    |--|--|--|--|--|--REDIRECT
.fi
.IP NAMELOOKUP
\fICURLINFO_NAMELOOKUP_TIME\fP. The time it took from the start until the name
resolving was completed.
.IP CONNECT
\fICURLINFO_CONNECT_TIME\fP. The time it took from the start until the connect
to the remote host (or proxy) was completed.
.IP APPCONNECT
\fICURLINFO_APPCONNECT_TIME\fP. The time it took from the start until the SSL
connect/handshake with the remote host was completed. (Added in in 7.19.0)
.IP PRETRANSFER
\fICURLINFO_PRETRANSFER_TIME\fP. The time it took from the start until the
file transfer is just about to begin. This includes all pre-transfer commands
and negotiations that are specific to the particular protocol(s) involved.
.IP STARTTRANSFER
\fICURLINFO_STARTTRANSFER_TIME\fP. The time it took from the start until the
first byte is received by libcurl.
.IP TOTAL
\fICURLINFO_TOTAL_TIME\fP. Total time of the previous request.
.IP REDIRECT
\fICURLINFO_REDIRECT_TIME\fP. The time it took for all redirection steps
include name lookup, connect, pretransfer and transfer before final
transaction was started. So, this is zero if no redirection took place.
.SH RETURN VALUE
If the operation was successful, CURLE_OK is returned. Otherwise an
appropriate error code will be returned.
.SH "SEE ALSO"
.BR curl_easy_setopt "(3)"