curlopt_sockoptfunction(3) [mojave man page]

CURLOPT_SOCKOPTFUNCTION(3)				     curl_easy_setopt options					CURLOPT_SOCKOPTFUNCTION(3)

NAME

       CURLOPT_SOCKOPTFUNCTION - set callback for setting socket options

SYNOPSIS

       #include <curl/curl.h>

       typedef enum  {
	 CURLSOCKTYPE_IPCXN,  /* socket created for a specific IP connection */
	 CURLSOCKTYPE_ACCEPT, /* socket created by accept() call */
	 CURLSOCKTYPE_LAST    /* never use */
       } curlsocktype;

       #define CURL_SOCKOPT_OK 0
       #define CURL_SOCKOPT_ERROR 1 /* causes libcurl to abort and return
				       CURLE_ABORTED_BY_CALLBACK */
       #define CURL_SOCKOPT_ALREADY_CONNECTED 2

       int sockopt_callback(void *clientp,
			    curl_socket_t curlfd,
			    curlsocktype purpose);

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SOCKOPTFUNCTION, sockopt_callback);

DESCRIPTION

       Pass a pointer to your callback function, which should match the prototype shown above.

       When set, this callback function gets called by libcurl when the socket has been created, but before the connect call to allow applications
       to change specific socket options. The callback's purpose argument identifies the exact purpose for this particular socket:

       CURLSOCKTYPE_IPCXN for actively created connections or since 7.28.0  CURLSOCKTYPE_ACCEPT  for  FTP  when  the  connection  was  setup  with
       PORT/EPSV (in earlier versions these sockets weren't passed to this callback).

       Future  versions  of  libcurl  may  support more purposes. libcurl passes the newly created socket descriptor to the callback in the curlfd
       parameter so additional setsockopt() calls can be done at the user's discretion.

       The clientp pointer contains whatever user-defined value set using the CURLOPT_SOCKOPTDATA(3) function.

       Return CURL_SOCKOPT_OK from the callback on success. Return CURL_SOCKOPT_ERROR from the callback function to signal an unrecoverable  error
       to  the	library and it will close the socket and return CURLE_COULDNT_CONNECT.	Alternatively, the callback function can return CURL_SOCK-
       OPT_ALREADY_CONNECTED, to tell libcurl that the socket is already connected and then libcurl will not attempt to connect it. This allows an
       application  to pass in an already connected socket with CURLOPT_OPENSOCKETFUNCTION(3) and then have this function make libcurl not attempt
       to connect (again).

DEFAULT

       By default, this callback is NULL and unused.

PROTOCOLS

       All

EXAMPLE

       TODO

AVAILABILITY

       Added in 7.16.0. The CURL_SOCKOPT_ALREADY_CONNECTED return code was added in 7.21.5.

RETURN VALUE

       Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.

SEE ALSO

       CURLOPT_SOCKOPTDATA(3), CURLOPT_OPENSOCKETFUNCTION(3),

libcurl 7.54.0							 February 03, 2016					CURLOPT_SOCKOPTFUNCTION(3)

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CURLOPT_IOCTLFUNCTION(3)				     curl_easy_setopt options					  CURLOPT_IOCTLFUNCTION(3)

NAME

       CURLOPT_IOCTLFUNCTION - callback for I/O operations

SYNOPSIS

       #include <curl/curl.h>

       typedef enum {
	 CURLIOE_OK,		/* I/O operation successful */
	 CURLIOE_UNKNOWNCMD,	/* command was unknown to callback */
	 CURLIOE_FAILRESTART,	/* failed to restart the read */
	 CURLIOE_LAST		/* never use */
       } curlioerr;

       typedef enum  {
	 CURLIOCMD_NOP, 	/* no operation */
	 CURLIOCMD_RESTARTREAD, /* restart the read stream from start */
	 CURLIOCMD_LAST 	/* never use */
       } curliocmd;

       curlioerr ioctl_callback(CURL *handle, int cmd, void *clientp);

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_IOCTLFUNCTION, ioctl_callback);

DESCRIPTION

       Pass a pointer to your callback function, which should match the prototype shown above.

       This  callback function gets called by libcurl when something special I/O-related needs to be done that the library can't do by itself. For
       now, rewinding the read data stream is the only action it can request. The rewinding of the read data stream may be necessary when doing  a
       HTTP PUT or POST with a multi-pass authentication method.

       The callback MUST return CURLIOE_UNKNOWNCMD if the input cmd is not CURLIOCMD_RESTARTREAD.

       The clientp argument to the callback is set with the CURLOPT_IOCTLDATA(3) option.

       This  option  is deprecated! Do not use it. Use CURLOPT_SEEKFUNCTION(3) instead to provide seeking! If CURLOPT_SEEKFUNCTION(3) is set, this
       parameter will be ignored when seeking.

DEFAULT

       By default, this parameter is set to NULL. Not used.

PROTOCOLS

       Used with HTTP

EXAMPLE

       TODO

AVAILABILITY

       Added in 7.12.3

RETURN VALUE

       Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.

SEE ALSO

       CURLOPT_IOCTLDATA(3), CURLOPT_SEEKFUNCTION(3),

libcurl 7.54.0							 February 03, 2016					  CURLOPT_IOCTLFUNCTION(3)

Linux and UNIX Man Pages

curlopt_sockoptfunction(3) [mojave man page]

Check Out this Related Man Page