isatty (3p) - Linux Man Pages
isatty: test for a terminal device
PROLOGThis 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.
isatty - test for a terminal device
The isatty() function may fail if:
- The fildes argument is not a valid open file descriptor.
The fildes argument is not associated with a terminal.
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.
COPYRIGHTPortions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 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 .