#include <syslog.h>
#include <errno.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <stdio.h>
#include <string.h>

void checkIsSocket(int fd)
{
	struct stat buf;
	memset(&buf, 0, sizeof (buf));
	if (fstat(fd, &buf) < 0)
	{
		syslog(LOG_INFO, "fstat() failed with %d\n", errno);
		return;
	}

	if (S_ISSOCK(buf.st_mode))
	{
		syslog(LOG_INFO, "fd %d is a socket\n", fd);
	}
	else
	{
		syslog(LOG_INFO, "fd %d is not a socket\n", fd);
	}
}

int main()
{
	checkIsSocket(0);
	checkIsSocket(1);
	checkIsSocket(2);

	char buf[1024];
	if (NULL == fgets(buf, 1024, stdin))
	{
		syslog(LOG_INFO, "stdin %s", strerror(errno));
	}
	if (EOF == fputs("yo", stdout))
	{
		syslog(LOG_INFO, "stdout %s", strerror(errno));
	}
	else
	{
		if (EOF == fflush(stdout))
		{
			syslog(LOG_INFO, "stdout flush %s", strerror(errno));
		}
	}
	if (EOF == fputs("yo", stderr))
	{
		syslog(LOG_INFO, "stderr %s", strerror(errno));
	}
	else
	{
		if (EOF == fflush(stderr))
		{
			syslog(LOG_INFO, "stderr flush %s", strerror(errno));
		}
	}
}