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.
isastream — test a file descriptor ( STREAMS)
int isastream(int fildes);
The isastream() function shall test whether fildes, an open file descriptor, is associated with a STREAMS-based file.
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.
The isastream() function shall fail if:
The following sections are informative.
The isastream() function may be removed in a future version.
The Base Definitions volume of POSIX.1‐2008, <stropts.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 .
- The fildes argument is not a valid open file descriptor.
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