Tcl-DP API for C
----------------

The file, dpApi.c, contains functions that can be used to contact
a Tcl-DP server and for sending RPCs and RDOs for evaluation by the
server.

Overview
--------


DpServer Dp_ConnectToServer(int inetAddr, int port);

Opens a connection to a Tcl-DP RPC server.  Note that the remote
server must have been opened using dp_MakeRPCServer or this function
will fail.  -1 will be returned if there was an error.  Both arguments
should be given in host byte order.


char *Dp_RPC(DpServer s, char *msg, struct timeval *tv, int *errorPtr);

This is the function used to send an RPC to server s.  msg is the
Tcl string to evaluate and tv is the timeout length (or NULL for infinite).
errorPtr will be non-zero when the function returns if there was an
error and the return value will be an error message.  Otherwise the
return value is the return value of the remote evaluation of the RPC.


int Dp_RDOSend(DPServer s, char *rdoStr, int flags);

Sends an RDO, rdoStr, to a Tcl-DP RPC server s.  flags is a combonation
of DP_REPORT_ERROR and DP_RETURN_VALUE.  These act the same as the
-callback and -error flags in the DP API.  Returns the amount of data
sent to the server (should be strlen(rdoStr)).


char *Dp_RDORead(DPServer s, int *errorPtr);

Receives a response from a previous RDO.  This will block forever
if there is no response to an RDO (e.g. asking for an error return
but there is no error).  Returns the Tcl return string or, if
errorPtr is non-zero, an error message.


int Dp_WaitForServer(DPServer s, struct timeval *tv);

Sleeps until there is a message from the server or tv expires.
If tv is NULL, we will block until data is received from the server.
Returns 0 if we timed out, < 0 if there was an error or > 0 if
the socket is now readable.


Bugs (oh no!)
-------------

Mail tcl-dp@cs.cornell.edu.