www.pudn.com > vxworks_networking.rar > nonBlockReadDemo.c

/* nonBlockReadDemo.c - This is an example of doing a nonBlocking read on a port
 in raw mode*/
 
 
 /*
 modification history
 --------------------
 
 01a,23dec99,cmf   written.
 */
 
 
 /*
 DESCRIPTION:
 This library is provided by Wind River Systems Customer
 Support strictly as an educational example.  It is unsupported
 and provided as-is.
 
 This is an example of doing a nonBlocking read on a port
 in raw mode.
 
 The first read blocks and waits for a character.  It then
 checks to see if additional characters have been sent as
 a result of pressing a special key such as <- (left arrow)
 
 If so, a special case is invoked to handle this (printf in this
 case)  
 
 What to do with the data is left up to the customer.
 
 */
 
 /* includes */
 
 #include 
 #include 
 #include 
 #include 
 #include 
 #include 
 #include 
 #include 
 
 /* defines */
 
 #define DELAY_BETWEEN_WRITES 100
 #define DELAY_BETWEEN_READS  10 
 
 #define NUMBER_OF_WRITES     15
 #define NUMBER_OF_READS	     25
 
 /*globals*/
 
 int  	fd1, fd2=0;
 SEM_ID 	syncSem;
 
 
 /* standard string should be about */
 
 #define READ_BUFFER_SIZE 4
 
 void readPort () 
     {
     int	 j, bytesRecvd, bytesRead=0;
     char * tPtr;
     char * inputString;	
     char inputChar;
    
     inputString = (char *) malloc(READ_BUFFER_SIZE);
 
 
     /* clear inputString */
     tPtr = inputString;
 
     for (j=0; j < READ_BUFFER_SIZE ;j++) 
         {
         *tPtr = '\0';
 	tPtr++;
 	}
 
     /* block waiting for input one character - standard string should 
      *  one charachter.  READ_BUFFER_SIZE allocated in case of special
      *  characters
      */	
 
     bytesRead = fioRdString (fd1,(char *) inputString,1);
     taskDelay(10);
 
     /* do any string processing here */
 	
     if (*inputString == 0x1b) 
         {
 		
 	/* check if more than one char was sent */
 	ioctl(fd1, FIONREAD, &bytesRecvd); 
 		
 	if (bytesRecvd == 0) printf("read: esc\n");
         else 
             {
 	    for (j=0;j