__fbufsize, __flbf, __fpending, __fpurge, __freadable, __freading, __fsetlocking, __fwritable, __fwriting, _flushlbf — interfaces to stdio FILE structure
#include <stdio.h> #include <stdio_ext.h>
size_t __fbufsize( |
FILE * | stream); |
size_t __fpending( |
FILE * | stream); |
int
__flbf( |
FILE * | stream); |
int
__freadable( |
FILE * | stream); |
int
__fwritable( |
FILE * | stream); |
int
__freading( |
FILE * | stream); |
int
__fwriting( |
FILE * | stream); |
int
__fsetlocking( |
FILE * | stream, |
| int | type); |
void
_flushlbf( |
void); |
void
__fpurge( |
FILE * | stream); |
Solaris introduced routines to allow portable access to the internals of the FILE structure, and glibc also implemented these.
The __fbufsize() function
returns the size of the buffer currently used by the given
stream.
The __fpending() function
returns the number of bytes in the output buffer. For
wide-oriented streams the unit is wide characters. This
function is undefined on buffers in reading mode, or opened
read-only.
The __flbf() function
returns a nonzero value if the stream is line-buffered, and
zero otherwise.
The __freadable() function
returns a nonzero value if the stream allows reading, and
zero otherwise.
The __fwritable() function
returns a nonzero value if the stream allows writing, and
zero otherwise.
The __freading() function
returns a nonzero value if the stream is read-only, or if the
last operation on the stream was a read operation, and zero
otherwise.
The __fwriting() function
returns a nonzero value if the stream is write-only (or
append-only), or if the last operation on the stream was a
write operation, and zero otherwise.
The __fsetlocking() function
can be used to select the desired type of locking on the
stream. It returns the current type. The type parameter can take the
following three values:
FSETLOCKING_INTERNALPerform implicit locking around every operation on the given stream (except for the *_unlocked ones). This is the default.
FSETLOCKING_BYCALLERThe caller will take care of the locking (possibly
using flockfile(3) in case
there is more than one thread), and the stdio routines
will not do locking until the state is reset to
FSETLOCKING_INTERNAL.
FSETLOCKING_QUERYDon't change the type of locking. (Only return it.)
The _flushlbf() function
flushes all line-buffered streams. (Presumably so that output
to a terminal is forced out, say before reading keyboard
input.)
The __fpurge() function
discards the contents of the stream's buffer.