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32 * @(#)fflush.c 8.1 (Berkeley) 6/4/93
33 * $FreeBSD: src/lib/libc/stdio/fflush.c,v 1.14 2007/01/09 00:28:06 imp Exp $
36 #include "namespace.h"
39 #include "un-namespace.h"
40 #include "libc_private.h"
44 static int sflush_locked(FILE *);
47 * Flush a single file, or (if fp is NULL) all files.
56 return (_fwalk(sflush_locked
));
60 * There is disagreement about the correct behaviour of fflush()
61 * when passed a file which is not open for reading. According to
62 * the ISO C standard, the behaviour is undefined.
63 * Under linux, such an fflush returns success and has no effect;
64 * under Windows, such an fflush is documented as behaving instead
66 * Given that applications may be written with the expectation of
67 * either of these two behaviours, the only safe (non-astonishing)
68 * option is to return EBADF and ask that applications be fixed.
69 * But for c++ compatibility do not enforce it and match FreeBSD.
71 if ((fp
->pub
._flags
& (__SWR
| __SRW
)) == 0)
74 retval
= __sflush(fp
);
80 * Flush a single file, or (if fp is NULL) all files.
89 return (_fwalk(sflush_locked
));
90 if ((fp
->pub
._flags
& (__SWR
| __SRW
)) == 0)
93 retval
= __sflush(fp
);
104 if ((t
& __SWR
) == 0)
107 if ((p
= fp
->_bf
._base
) == NULL
)
110 n
= fp
->pub
._p
- p
; /* write this much */
113 * Set these immediately to avoid problems with longjmp and to allow
114 * exchange buffering (via setvbuf) in user write function.
117 fp
->pub
._w
= t
& (__SLBF
|__SNBF
) ? 0 : fp
->_bf
._size
;
119 for (; n
> 0; n
-= t
, p
+= t
) {
120 t
= _swrite(fp
, (char *)p
, n
);
122 /* Reset _p and _w. */
123 if (p
> fp
->pub
._p
) {
124 /* Some was written. */
125 memmove(fp
->pub
._p
, p
, n
);
127 if ((fp
->pub
._flags
& (__SLBF
| __SNBF
)) == 0)
130 fp
->pub
._flags
|= __SERR
;
138 sflush_locked(FILE *fp
)