mesg_recv.c

让你了解Unix进程间的通信是如何实现的

/* include mesg_recv */
#include	"mesg.h"

ssize_t
mesg_recv(int fd, struct mymesg *mptr)
{
	size_t	len;
	ssize_t	n;

		/* 4read message header first, to get len of data that follows */
	if ( (n = Read(fd, mptr, MESGHDRSIZE)) == 0)
		return(0);		/* end of file */
	else if (n != MESGHDRSIZE)
		err_quit("message header: expected %d, got %d", MESGHDRSIZE, n);

	if ( (len = mptr->mesg_len) > 0)
		if ( (n = Read(fd, mptr->mesg_data, len)) != len)
			err_quit("message data: expected %d, got %d", len, n);
	return(len);
}
/* end mesg_recv */

ssize_t
Mesg_recv(int fd, struct mymesg *mptr)
{
	return(mesg_recv(fd, mptr));
}