fd = open("/dev/ttyS0", O_RDWR | O_NOCTTY | O_NDELAY);

close(fd);

//sc_comm.h
//Server client communication functions
//Written initially to support db_server & db_client, but should be able to be used
//with any tcp/ip communication protocol program
/*********************************************************************************
***  Credits:                                                                  ***
***     A major portion of the TCP/IP code was derived from some excellent     ***
***     short course notes "UNIX, Network Programming with TCP/IP" written by  ***
***     Alan Dix, copyright 1986.  This paper can be found at:                 ***
***     [url]www.hiraeth.com/alan/tutorials[/url].  The code derived herein is derived    ***
***     from his examples.  Any break or misimplementation is due to my less   ***
***     than adequate knowledge of the topic.                                  ***
*********************************************************************************/

#ifndef __SC_COMM
#define __SC_COMM

//System include files to enable tcp/ip communication
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>

//tcp_send WAIT MACROS
#define	WAIT	1
#define	NO_WAIT	0

//Server side functions
int 	tcp_listen(int port, char* ip_add);					//Open a socket and listen for incoming client connections
int 	tcp_loop(int port);									//Begin indefinite loop to process client connections
int		tcp_send(int socket, char* buffer, int wait);		//Send string buffer with optional wait

//Client side functions
int		tcp_connect(char *ip_add, int portno);				//Request client connection
#endif