bionic (3) isatty.3posix.gz

Provided by: manpages-posix-dev_2013a-2_all bug

PROLOG
       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
       isatty — test for a terminal device


SYNOPSIS
       #include <unistd.h>

       int isatty(int fildes);


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


RETURN VALUE
       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
       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
       None.


APPLICATION 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.


RATIONALE
       None.


FUTURE DIRECTIONS
       None.


SEE ALSO
       The Base Definitions volume of POSIX.1‐2008, <unistd.h>


       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 .