NAME
__fpending,
__freadahead, __freading,
__freadptr, __freadptrinc,
__fseterr, __fwriting
— stream extension
functions
SYNOPSIS
#include
<stdio_ext.h>
size_t
__fpending(FILE
*stream);
size_t
__freadahead(FILE
*stream);
int
__freading(FILE
*stream);
const char *
__freadptr(FILE
*stream, size_t
*sizep);
void
__freadptrinc(FILE
*stream, size_t
increment);
void
__fseterr(FILE
*stream);
int
__fwriting(FILE
*stream);
DESCRIPTION
The
__fpending()
function returns the number of bytes of output data currently buffered on
stream.
The
__freadahead()
function returns the number of bytes of input data currently buffered on
stream.
The
__freading()
function returns non-zero if stream either was opened
read-only or if the last operation on the stream was a read or push-back
operation.
The
__freadptr()
function returns either a pointer to the next byte of buffered input data on
stream and stores the number of consecutive bytes of
buffered data available to the location pointed to by
sizep, or return NULL if
there's no buffered input data. The value returned via
sizep may differ from the value that would be returned
by __freadahead().
The
__freadptrinc()
function consumes increment bytes of buffered input
data on stream. This is only valid immediately after a
non-NULL return from __freadptr() and
increment must not be greater than the size value from
that call.
The
__fseterr()
function sets the error indicator for stream.
The
__fwriting()
function returns non-zero if stream either was opened
write-only or append-only or if the last operation on the stream was a write
operation.
ERRORS
These functions should not fail and do not set the external variable errno.
SEE ALSO
HISTORY
The __fpending(),
__freadahead(),
__freading(), __freadptr(),
__freadptrinc(),
__fseterr(), and
__fwriting() functions appeared in
OpenBSD 7.6.
BUGS
These functions are under-specified and non-portable. They exist to permit a particular “portability” library to function without direct manipulation of stdio structures; everyone else should either implement their own stdio layer, do the work of defining and standardizing the required functionality, or reconsider their life decisions.