/*
Copyright (C) Magna Carta Software, Inc. 1990.  All Rights Reserved
C COMMUNICATIONS TOOLKIT
RXCOUNT.C -- Return the number of bytes in the RX buffer.
*/


#include <ccttype.h>


/*
C_RXCOUNT -- return the number of bytes in the receive buffer.
Parameters:
COMM_PORT *p -- pointer to the port;
*/
WORD c_rxcount(COMM_PORT *p)
{
    if (!(p->intr & 1)) return (0);
    if (p->rxbufhead >= p->rxbuftail) return(p->rxbufhead - p->rxbuftail);
    else return(p->rx_bufsiz - (p->rxbuftail - p->rxbufhead));
}