opensolaris man page for isatty

isatty(3C)						   Standard C Library Functions 						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	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |MT-Safe			   |
       +-----------------------------+-----------------------------+

SEE ALSO
       ttyname(3C), attributes(5), standards(5)

SunOS 5.11							    24 Jul 2002 							isatty(3C)