PROLOG | NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | EXAMPLES | APPLICATION USAGE | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT 

ISATTY(3P)                POSIX Programmer's Manual               ISATTY(3P)

PROLOG         top

       This manual page is part of the POSIX Programmer's Manual.  The Linux
       implementation of this interface may differ (consult the
       corresponding Linux manual page for details of Linux behavior), or
       the interface may not be implemented on Linux.

NAME         top

       isatty — test for a terminal device

SYNOPSIS         top

       #include <unistd.h>
       int isatty(int fildes);

DESCRIPTION         top

       The isatty() function shall test whether fildes, an open file
       descriptor, is associated with a terminal device.

RETURN VALUE         top

       The isatty() function shall return 1 if fildes is associated with a
       terminal; otherwise, it shall return 0 and may set errno to indicate
       the error.

ERRORS         top

       The isatty() function may fail if:
       EBADF  The fildes argument is not a valid open file descriptor.
       ENOTTY The file associated with the fildes argument is not a
              terminal.
       The following sections are informative.

EXAMPLES         top

       None.

APPLICATION USAGE         top

       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.

RATIONALE         top

       None.

FUTURE DIRECTIONS         top

       None.

SEE ALSO         top

       The Base Definitions volume of POSIX.1‐2008, unistd.h(0p)

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The Open
       Group Base Specifications Issue 7, Copyright (C) 2013 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
       applied.) In the event of any discrepancy between this version and
       the original IEEE and The Open Group Standard, the original IEEE and
       The Open Group Standard is the referee document. The original
       Standard can be obtained online at http://www.unix.org/online.html .
       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the
       source files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group                 2013                          ISATTY(3P)

Pages that refer to this page: unistd.h(0p),  tty(1p)