#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>

#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/msg.h>


typedef struct	test_message
{
    long	mtype;
    char	mtext[512 - sizeof(long)];
} test_message;


static int	test_pipe(void);
static int	test_msg(void);


int
main(int argc, char *argv[])
{
    if(test_pipe() < 0)
    	return 1;

    if(test_msg() < 0)
    	return 1;

    return 0;
}


static int
test_pipe(void)
{
    int		p[2];
    char	buf[512];
    int		done;
    int		rc;

    if (pipe(p) < 0)
    {
    	perror("pipe(2)");
	return -1;
    }

    if (fcntl(p[1], F_SETFL, O_NONBLOCK) < 0)
    {
    	perror("fcntl(2)");
	return -1;
    }

    for(done = 0; ; )
    {
    	if ((rc = write(p[1], buf, sizeof(buf))) != sizeof(buf))
	{
	    if (rc < 0)
	    {
	    	extern int errno;

	    	if (errno == EAGAIN)
		{
		    printf("Pipe buffer is %d bytes\n", done);
		    return 0;
		}

	    	perror("write(2)");
		return -1;
	    }

	    fprintf(stderr, "whatever happened - rc = %d on write(2)\n", rc);
	    return -1;
	}
	done += rc;
    }

    fprintf(stderr, "Endless write loop returned - what's that?\n");
    return -1;
}


static int
test_msg(void)
{
    int			mq;
    test_message	msg;
    int			done;

    if ((mq = msgget(IPC_PRIVATE, IPC_CREAT | 0600)) < 0)
    {
    	perror("msgget(2)");
	return -1;
    }

    for (done = 0; ; )
    {
    	msg.mtype = 1;
	if (msgsnd(mq, &msg, sizeof(msg), IPC_NOWAIT) < 0)
	{
	    extern int	errno;

	    if (errno == EAGAIN)
	    {
		printf("Sys-V message queue buffer is %d bytes\n", done);
		return 0;
	    }

	    perror("msgsnd(2)");
	    return -1;
	}
	done += sizeof(msg);
    }

    fprintf(stderr, "Endless write loop returned - what's that?\n");
    return -1;
}