FILENO
Section: POSIX Programmer's Manual (P)
Updated: 2003
NAME
fileno - map a stream pointer to a file descriptor
SYNOPSIS
#include <stdio.h>
int fileno(FILE *stream);
DESCRIPTION
The fileno() function shall return the integer file descriptor
associated with the stream pointed to by
stream.
RETURN VALUE
Upon successful completion, fileno() shall return the integer
value of the file descriptor associated with stream.
Otherwise, the value -1 shall be returned and errno set to indicate
the error.
ERRORS
The fileno() function may fail if:
- EBADF
-
The stream argument is not a valid stream.
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
None.
RATIONALE
Without some specification of which file descriptors are associated
with these streams, it is impossible for an application to
set up the streams for another application it starts with fork()
and exec. In particular, it would not be possible to write a
portable version of the sh command interpreter (although there
may be other constraints that would prevent that
portability).
FUTURE DIRECTIONS
None.
SEE ALSO
Interaction of File Descriptors and Standard I/O Streams , fdopen()
, fopen() , stdin() , the Base
Definitions volume of IEEE Std 1003.1-2001, <stdio.h>
COPYRIGHT
Portions 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 .
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUE
-
- ERRORS
-
- EXAMPLES
-
- APPLICATION USAGE
-
- RATIONALE
-
- FUTURE DIRECTIONS
-
- SEE ALSO
-
- COPYRIGHT
-
This document was created by
man2html,
using the manual pages.
Time: 07:35:27 GMT, March 26, 2013