active.c

REBIT单片机网络编程例程,跟培训教程.

/**********************************************************************
 *		Samples\TcpIp\active.c
 *		Copyright (c) 2001, Z-World (jjb)
 *		This program demonstrates the tcp_open call.
 *
 * 	A simple demonstration of a TCP/IP session, by retrieving a
 * 	web page from a remote site.  Change DEST and PORT to the
 * 	remote machine.
 *
 **********************************************************************/

#class auto


/***********************************
 * Configuration                   *
 * -------------                   *
 * All fields in this section must *
 * be altered to match your local  *
 * network settings.               *
 ***********************************/

/*
 * Pick the predefined TCP/IP configuration for this sample.  See
 * LIB\TCPIP\TCP_CONFIG.LIB for instructions on how to set the
 * configuration.
 */
#define TCPCONFIG 1


#use "dcrtcp.lib"

/*
 *  Remote computer to contact:
 */
#define  DEST 		"www.zworld.com"
#define  PORT 		80

////////////////////////////////////////////////////////////////////////

void main()
{
	char	buffer[100]; 	/* Currently (DC 7.30), printf() has max 127 bytes it can output. */
	int 	bytes_read;
	longword  destIP;
	tcp_Socket socket;

	printf( "initializing..\n" );
	sock_init();
	// Wait for the interface to come up
	while (ifpending(IF_DEFAULT) == IF_COMING_UP) {
		tcp_tick(NULL);
	}
	
	if( 0L == (destIP = resolve(DEST)) ) {
		printf( "ERROR: Cannot resolve \"%s\" into an IP address\n", DEST );
		exit(2);
	}
	tcp_open(&socket,0,destIP,PORT,NULL);

	printf("Waiting for connection...\n");
	while(!sock_established(&socket) && sock_bytesready(&socket)==-1) {
		tcp_tick(NULL);
	}

	printf("Connection established, sending get request...\n");

	/*
	 *  If don't send the HTTP version number, then server believes we are
	 *  a pre-1.0 version client.
	 */
	sock_write(&socket,"GET /\r\n\r\n",9);

	/*
	 *  When tcp_tick()-ing on a specific socket, we get non-zero return while
	 *  it is active, and zero when it is closed (as used here).
	 */
	do {
		bytes_read=sock_fastread(&socket,buffer,sizeof(buffer)-1);

		if(bytes_read>0) {
			buffer[bytes_read] = '\0';
			/*
			 * By using the "%s" format, if there are "%" in the buffer, printf()
			 *  won't try to interpret them!
			 */
			printf("%s",buffer);
		}
	} while(tcp_tick(&socket));

	sock_abort(&socket);
	printf("\nConnection closed...\n");
}