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man pages section 3: Library Interfaces and Headers

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Updated: Thursday, June 13, 2019

curl_easy_recv (3)


curl_easy_recv - receives raw data on an "easy" connection


#include <curl/easy.h>

CURLcode  curl_easy_recv(  CURL  *curl,  void  *buffer,  size_t buflen,
size_t *n);


curl_easy_recv(3)               libcurl Manual               curl_easy_recv(3)

       curl_easy_recv - receives raw data on an "easy" connection

       #include <curl/easy.h>

       CURLcode  curl_easy_recv(  CURL  *curl,  void  *buffer,  size_t buflen,
       size_t *n);

       This function receives raw data from the  established  connection.  You
       may  use  it together with curl_easy_send(3) to implement custom proto-
       cols using libcurl. This functionality can be  particularly  useful  if
       you  use proxies and/or SSL encryption: libcurl will take care of proxy
       negotiation and connection set-up.

       buffer is a pointer to your buffer that will  get  the  received  data.
       buflen  is  the  maximum amount of data you can get in that buffer. The
       variable n points to will receive the number of received bytes.

       To establish the connection, set CURLOPT_CONNECT_ONLY(3) option  before
       calling   curl_easy_perform(3)   or  curl_multi_perform(3).  Note  that
       curl_easy_recv(3) does not work on connections that were created  with-
       out this option.

       The  call  will  return  CURLE_AGAIN  if there is no data to read - the
       socket is used in non-blocking mode  internally.  When  CURLE_AGAIN  is
       returned,  use  your operating system facilities like select(2) to wait
       for data. The socket may be obtained  using  curl_easy_getinfo(3)  with

       Wait  on the socket only if curl_easy_recv(3) returns CURLE_AGAIN.  The
       reason for this is libcurl or the SSL library may internally cache some
       data,  therefore  you  should  call curl_easy_recv(3) until all data is
       read which would include any cached data.

       Furthermore if you wait on the socket and it tells you there is data to
       read,  curl_easy_recv(3)  may  return CURLE_AGAIN if the only data that
       was read was for internal SSL processing, and no other data  is  avail-

       Added in 7.18.2.

       On success, returns CURLE_OK, stores the received data into buffer, and
       the number of bytes it actually read into *n.

       On failure, returns the appropriate error code.

       The function may return CURLE_AGAIN. In this case, use  your  operating
       system facilities to wait until data can be read, and retry.

       Reading exactly 0 bytes indicates a closed connection.

       If  there's no socket available to use from the previous transfer, this
       function returns CURLE_UNSUPPORTED_PROTOCOL.

       See sendrecv.c in docs/examples directory for usage example.

       See attributes(7) for descriptions of the following attributes:

       |Availability   | web/curl         |
       |Stability      | Uncommitted      |
       curl_easy_setopt(3),    curl_easy_perform(3),     curl_easy_getinfo(3),

       This     software     was    built    from    source    available    at
       https://github.com/oracle/solaris-userland.   The  original   community
       source    was    downloaded    from    https://github.com/curl/curl/ar-

       Further information about this software can be found on the open source
       community website at http://curl.haxx.se/.

libcurl 7.18.2                   29 April 2008               curl_easy_recv(3)