msg.h

#define MAX_MSG_PAYLOAD 100

/* The information type */
#define SENDER_DATA_TYPE 1

/* The done message */
#define RECV_DONE_TYPE 2

/* The file name transfer message */
#define FILE_NAME_TRANSFER_TYPE 3

/* The maximum size of the file name */
#define MAX_FILE_NAME_SIZE 100

/**
 * The structure representing the message
 * used by sender to send the name of the file
 * to be transfered to the receiver.
 */
struct fileNameMsg
{	
	/* The message type */
	long mtype;	
	
	/* The name of the file */
	char fileName[MAX_FILE_NAME_SIZE];
	
	/**
 	 * Prints the structure
 	 * @param fp - the file stream to print to
 	 */
	void print(FILE* fp)
	{
		fprintf(fp, "%ld %s\n", mtype, fileName);
	}
};

/**
 * The message structure representing the message
 * sent from the sender to the receiver indicating
 * the number of bytes in the shared memory segment 
 * that are ready to read. 
 */

struct message
{
	/* The message type */
	long mtype;
	
	/* How many bytes in the message */
	int size;
	
	/**
 	 * Prints the structure
 	 * @param fp - the file stream to print to
 	 */
	void print(FILE* fp)
	{
		fprintf(fp, "%ld %d", mtype, size);
	}
};

/* Struct representing the message sent from the receiver
 * to the sender acknowledging the successful reception and
 * saving of data.
 */
struct ackMessage
{
	/* The type of message */
	long mtype;
	
	/**
 	 * Prints the structure
 	 * @param fp - the file stream to print to
 	 */
	
	void print(FILE* fp)
	{
		fprintf(fp, "%ld\n", mtype);
	}
};