Ubuntu Manpage: curl_easy_getinfo - extract information from a curl handle

Provided by: libcurl4-doc_7.35.0-1ubuntu2.20_all

NAME

       curl_easy_getinfo - extract information from a curl handle

SYNOPSIS

       #include <curl/curl.h>

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

DESCRIPTION

       Request internal information from the curl session with this function.  The third argument
       MUST 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-
       oriented data.

       You should not free the memory returned by this function unless it is explicitly mentioned
       below.

AVAILABLE INFORMATION

The following information can be extracted:

CURLINFO_EFFECTIVE_URL
Pass a pointer to a char pointer to receive the last used effective URL.

CURLINFO_RESPONSE_CODE
Pass a pointer to a long to receive the last received HTTP, FTP or SMTP response
code. This option was previously known as CURLINFO_HTTP_CODE in libcurl 7.10.7 and
earlier. The value will be zero if no server response code has been received. Note
that a proxy's CONNECT response should be read with CURLINFO_HTTP_CONNECTCODE and
not this.

Support for SMTP responses added in 7.25.0.

CURLINFO_HTTP_CONNECTCODE
Pass a pointer to a long to receive the last received proxy response code to a
CONNECT request.

CURLINFO_FILETIME
Pass a pointer to a long to receive the remote time of the retrieved document (in
number of seconds since 1 jan 1970 in the GMT/UTC time zone). If you get -1, it can
be because of many reasons (unknown, the server hides it or the server doesn't
support the command that tells document time etc) and the time of the document is
unknown. Note that you must tell the server to collect this information before the
transfer is made, by using the CURLOPT_FILETIME option to curl_easy_setopt(3) or
you will unconditionally get a -1 back. (Added in 7.5)

CURLINFO_TOTAL_TIME
Pass a pointer to a double to receive the total time in seconds for the previous
transfer, including name resolving, TCP connect etc.

CURLINFO_NAMELOOKUP_TIME
Pass a pointer to a double to receive the time, in seconds, it took from the start
until the name resolving was completed.

CURLINFO_CONNECT_TIME
Pass a pointer to a double to receive the time, in seconds, it took from the start
until the connect to the remote host (or proxy) was completed.

CURLINFO_APPCONNECT_TIME
Pass a pointer to a double to receive the time, in seconds, it took from the start
until the SSL/SSH connect/handshake to the remote host was completed. This time is
most often very near to the PRETRANSFER time, except for cases such as HTTP
pippelining where the pretransfer time can be delayed due to waits in line for the
pipeline and more. (Added in 7.19.0)

CURLINFO_PRETRANSFER_TIME
Pass a pointer to a double to receive the time, in seconds, 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.
It does not involve the sending of the protocol- specific request that triggers a
transfer.

CURLINFO_STARTTRANSFER_TIME
Pass a pointer to a double to receive the time, in seconds, it took from the start
until the first byte is received by libcurl. This includes
CURLINFO_PRETRANSFER_TIME and also the time the server needs to calculate the
result.

CURLINFO_REDIRECT_TIME
Pass a pointer to a double to receive the total time, in seconds, it took for all
redirection steps include name lookup, connect, pretransfer and transfer before
final transaction was started. CURLINFO_REDIRECT_TIME contains the complete
execution time for multiple redirections. (Added in 7.9.7)

CURLINFO_REDIRECT_COUNT
Pass a pointer to a long to receive the total number of redirections that were
actually followed. (Added in 7.9.7)

CURLINFO_REDIRECT_URL
Pass a pointer to a char pointer to receive the URL a redirect would take you to if
you would enable CURLOPT_FOLLOWLOCATION. This can come very handy if you think
using the built-in libcurl redirect logic isn't good enough for you but you would
still prefer to avoid implementing all the magic of figuring out the new URL.
(Added in 7.18.2)

CURLINFO_SIZE_UPLOAD
Pass a pointer to a double to receive the total amount of bytes that were uploaded.

CURLINFO_SIZE_DOWNLOAD
Pass a pointer to a double to receive the total amount of bytes that were
downloaded. The amount is only for the latest transfer and will be reset again for
each new transfer.

CURLINFO_SPEED_DOWNLOAD
Pass a pointer to a double to receive the average download speed that curl measured
for the complete download. Measured in bytes/second.

CURLINFO_SPEED_UPLOAD
Pass a pointer to a double to receive the average upload speed that curl measured
for the complete upload. Measured in bytes/second.

CURLINFO_HEADER_SIZE
Pass a pointer to a long to receive the total size of all the headers received.
Measured in number of bytes.

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.

CURLINFO_SSL_VERIFYRESULT
Pass a pointer to a long to receive the result of the certification verification
that was requested (using the CURLOPT_SSL_VERIFYPEER option to
curl_easy_setopt(3)).

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.
NOTE: you must call curl_slist_free_all(3) on the list pointer once you're done
with it, as libcurl will not free the data for you. (Added in 7.12.3)

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.

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.

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.

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 CURLOPT_PRIVATE option to
curl_easy_setopt(3)). Please note that for internal reasons, the value is returned
as a char pointer, although effectively being a 'void *'. (Added in 7.10.3)

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 CURLOPT_HTTPAUTH
option for curl_easy_setopt(3). (Added in 7.10.8)

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)

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)

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 CURLINFO_REDIRECT_COUNT you are able to know how many times libcurl
successfully reused existing connection(s) or not. See the Connection Options of
curl_easy_setopt(3) to see how libcurl tries to make persistent connections to save
time. (Added in 7.12.3)

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 curl 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)

CURLINFO_PRIMARY_PORT
Pass a pointer to a long to receive the destination port of the most recent
connection done with this curl handle. (Added in 7.21.0)

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
curl handle. This string may be IPv6 if that's enabled. The same restrictions apply
as to CURLINFO_PRIMARY_IP. (Added in 7.21.0)

CURLINFO_LOCAL_PORT
Pass a pointer to a long to receive the local (source) port of the most recent
connection done with this curl handle. (Added in 7.21.0)

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 curl_slist_free_all(3) 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)

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 CURLOPT_CONNECT_ONLY. (Added in 7.15.2)

NOTE: this API is not really working on win64, since the SOCKET type on win64 is 64
bit large while its 'long' is only 32 bits.

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

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 CURLOPT_CERTINFO 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, GSKit or QsoSSL support. (Added in 7.19.1)

CURLINFO_TLS_SESSION
Pass a pointer to a 'struct curl_tlsinfo *'. The pointer will be initialized to
refer to a 'struct curl_tlsinfo *' 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)

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 CURLOPT_TIMECONDITION). 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)

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.

CURLINFO_RTSP_CLIENT_CSEQ
Pass a pointer to a long to receive the next CSeq that will be used by the
application.

CURLINFO_RTSP_SERVER_CSEQ
Pass a pointer to a long to receive the next server CSeq that will be expected by
the application.

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

Applications wishing to resume an RTSP session on another connection should
retrieve this info before closing the active connection.

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 CURLE_RTSP_CSEQ_ERROR then you may wish to
troubleshoot and/or fix the CSeq mismatch by peeking at this value.

TIMES

       An overview of the six time values available from curl_easy_getinfo()

       curl_easy_perform()
           |
           |--NAMELOOKUP
           |--|--CONNECT
           |--|--|--APPCONNECT
           |--|--|--|--PRETRANSFER
           |--|--|--|--|--STARTTRANSFER
           |--|--|--|--|--|--TOTAL
           |--|--|--|--|--|--REDIRECT

       NAMELOOKUP
              CURLINFO_NAMELOOKUP_TIME. The time it took from the start until the name  resolving
              was completed.

       CONNECT
              CURLINFO_CONNECT_TIME.  The  time  it  took from the start until the connect to the
              remote host (or proxy) was completed.

       APPCONNECT
              CURLINFO_APPCONNECT_TIME.  The  time  it  took  from  the  start  until   the   SSL
              connect/handshake with the remote host was completed. (Added in in 7.19.0)

       PRETRANSFER
              CURLINFO_PRETRANSFER_TIME.  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.

       STARTTRANSFER
              CURLINFO_STARTTRANSFER_TIME.  The  time it took from the start until the first byte
              is received by libcurl.

       TOTAL  CURLINFO_TOTAL_TIME. Total time of the previous request.

       REDIRECT
              CURLINFO_REDIRECT_TIME. 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.

RETURN VALUE