//pipemesg/mesg.h
#include "unpipc.h"

/*   "",     , FIFO    */
/*  ,  sizeof(struct mymesg) <= PIPE_BUF */
#define MAXMESGDATA (PIPE_BUF - 2*sizeof(long))
/*  mesg_len  mesg_type */
#define MESGHDRSIZE (sizeof(struct mymesg) - MAXMESGDATA)
struct mymesg {
long mesg_len;	//   mesg_data,   0
long mesg_type;// ,   > 0
char mesg_data[MAXMESGDATA];
};
ssize_t mesg_send(int, struct mymesg *);
void Mesg_send(int, struct mymesg *);
ssize_t mesg_recv(int, struct mymesg *);
ssize_t Mesg_recv(int, struct mymesg *);
