/* isatty.c */ /* Dumb implementation so programs will at least run. */ #include <sys/stat.h> #include <errno.h> int _DEFUN(_isatty, (fd), int fd) { struct stat buf; if (fstat (fd, &buf) < 0) { errno = EBADF; return 0; } if (S_ISCHR (buf.st_mode)) return 1; errno = ENOTTY; return 0; }