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

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
       isastream -- test a file descriptor (STREAMS)

SYNOPSIS
       #include <stropts.h>

       int isastream(int fildes);

DESCRIPTION
       The isastream() function shall test whether fildes, an open file
       descriptor, is associated with a STREAMS-based file.

RETURN VALUE
       Upon successful completion, isastream() shall return 1 if fildes refers
       to a STREAMS-based file and 0 if not. Otherwise, isastream() shall
       return -1 and set errno to indicate the error.

ERRORS
       The isastream() function shall fail if:

       EBADF  The fildes argument is not a valid open file descriptor.

       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       None.

RATIONALE
       None.

FUTURE DIRECTIONS
       The isastream() function may be removed in a future version.

SEE ALSO
       The Base Definitions volume of POSIX.1-2017, <stropts.h>

COPYRIGHT
       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                        ISASTREAM(3P)