isatty(3C)
NAME
isatty − test for a terminal device
SYNOPSIS
#include <unistd.h>
int isatty(int fildes);
DESCRIPTION
The isatty() function tests whether fildes, an open file descriptor, is associated with a terminal device.
RETURN VALUES
The isatty() function returns 1 if fildes is associated with a terminal; otherwise it returns 0 and may set errno to indicate the error.
ERRORS
The isatty() function may fail if:
EBADF The fildes argument is not a valid open file descriptor.
ENOTTY The fildes argument is not associated with a terminal.
USAGE
The isatty() function does not necessarily indicate that a human being is available for interaction via fildes. It is quite possible that non-terminal devices are connected to the communications line.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
| MT-Level | MT-Safe in multi-thread applications |
SEE ALSO
SunOS 5.6 — Last change: 29 Dec 1996