.\" $Id: libssh2_session_callback_set.3,v 1.2 2009/03/17 10:34:27 bagder Exp $
.\"
.TH libssh2_session_callback_set 3 "1 Jun 2007" "libssh2 0.15" "libssh2 manual"
.SH NAME
libssh2_session_callback_set - set a callback function
.SH SYNOPSIS
.nf
#include <libssh2.h>

void *libssh2_session_callback_set(LIBSSH2_SESSION *session,
                                   int cbtype, void *callback);
.SH DESCRIPTION
Sets a custom callback handler for a previously initialized session
object. Callbacks are triggered by the receipt of special packets at the
Transport layer. To disable a callback, set it to NULL.

\fIsession\fP - Session instance as returned by 
.BR libssh2_session_init_ex(3)

\fIcbtype\fP - Callback type. One of the types listed in Callback Types.

\fIcallback\fP - Pointer to custom callback function. The prototype for 
this function must match the associated callback declaration macro.
.SH CALLBACK TYPES
.IP LIBSSH2_CALLBACK_IGNORE
Called when a SSH_MSG_IGNORE message is received
.IP LIBSSH2_CALLBACK_DEBUG
Called when a SSH_MSG_DEBUG message is received
.IP LIBSSH2_CALLBACK_DISCONNECT
Called when a SSH_MSG_DISCONNECT message is received
.IP LIBSSH2_CALLBACK_MACERROR
Called when a mismatched MAC has been detected in the transport layer. If the
function returns 0, the packet will be accepted nonetheless.
.IP LIBSSH2_CALLBACK_X11
Called when an X11 connection has been accepted
.SH RETURN VALUE
Pointer to previous callback handler. Returns NULL if no prior callback
handler was set or the callback type was unknown.
.SH SEE ALSO
.BR libssh2_session_init_ex(3)