Tcl Source Code

The Tcl event loop should be running while an asynchronous connection
is in progress, because it may have to do several connection attempts
in the background. Running the event loop also allows you to set up a
writable channel event on the socket to get notified when the
asynchronous connection has succeeded or failed. See the \fBvwait\fR
and the \fBchan\fR commands for more details on the event loop and
channel events.
.PP
The \fBchan configure\fR option \fB-connecting\fR may be used to check if the connect is still running. To verify a successful connect, the option \fB-error\fR may be checked when \fB-connecting\fR returned 0. 
.PP
Operation without the event queue requires at the moment calls to \fBchan configure\fR to advance the internal state machine. 
.RE
.SH "SERVER SOCKETS"
.PP
If the \fB\-server\fR option is specified then the new socket will be
a server that listens on the given \fIport\fR (either an integer or a
service name, where supported and understood by the host operating
system; if \fIport\fR is zero, the operating system will allocate a

\fB\-peername\fR
.
This option is not supported by server sockets. For client and accepted
sockets, this option returns a list of three elements; these are the
address, the host name and the port to which the peer socket is connected
or bound. If the host name cannot be computed, the second element of the
list is identical to the address, its first element.
.RE
.TP
\fB\-connecting\fR
.
This option is not supported by server sockets. For client sockets, this option returns 1 if an asyncroneous connect is still in progress, 0 otherwise.
.PP
.SH "EXAMPLES"
.PP
Here is a very simple time server:
.PP
.CS
proc Server {startTime channel clientaddr clientport} {

                        "can't get sockname: %s", Tcl_PosixError(interp)));
            }
	    return TCL_ERROR;
	}
    }

    if (len > 0) {
	return Tcl_BadChannelOption(interp, optionName, "peername sockname");
	return Tcl_BadChannelOption(interp, optionName, "connecting peername sockname");
    }

    return TCL_OK;
}

/*
 *----------------------------------------------------------------------

	}
    }
#endif /*TCL_FEATURE_KEEPALIVE_NAGLE*/

    if (len > 0) {
#ifdef TCL_FEATURE_KEEPALIVE_NAGLE
	return Tcl_BadChannelOption(interp, optionName,
		"peername sockname keepalive nagle");
		"connecting peername sockname keepalive nagle");
#else
	return Tcl_BadChannelOption(interp, optionName, "peername sockname");
	return Tcl_BadChannelOption(interp, optionName, "connecting peername sockname");
#endif /*TCL_FEATURE_KEEPALIVE_NAGLE*/
    }

    return TCL_OK;
}

/*