isatty(3p) — Linux manual page

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.1‐2017, unistd.h(0p)

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic
       form from IEEE Std 1003.1-2017, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The
       Open Group Base Specifications Issue 7, 2018 Edition, Copyright
       (C) 2018 by the Institute of Electrical and Electronics Engineers,
       Inc and The Open Group.  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.opengroup.org/unix/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                2017                        ISATTY(3P)

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

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