t_isatty.c

该代码为unix环境高级编程的源代码

#include	"ourhdr.h"

int
main(void)
{
	printf("fd 0: %s\n", isatty(0) ? "tty" : "not a tty");
	printf("fd 1: %s\n", isatty(1) ? "tty" : "not a tty");
	printf("fd 2: %s\n", isatty(2) ? "tty" : "not a tty");
	exit(0);
}