Determining the common data

• Define KEY for the unique identification number of the queue.

• Define MAXLEN for the maximum message length.

• Define msg_1_t for the client message.

• Define msg_2_t for the response from the server.

message-types.h

#ifndef MSG_TYPES
#define MSG_TYPES

#define KEY 1274
#define MAXLEN 512

struct msg_1_t
{
   long mtype;
   int snd_pid;
   char body[MAXLEN];
};

struct msg_2_t
{
   long mtype;
   int snd_pid;
   int rcv_pid;
   char body[MAXLEN];
};

#endif