diff options
Diffstat (limited to 'lib/libc/stdio/fflush.c')
| -rw-r--r-- | lib/libc/stdio/fflush.c | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/lib/libc/stdio/fflush.c b/lib/libc/stdio/fflush.c new file mode 100644 index 0000000..3090dc9 --- /dev/null +++ b/lib/libc/stdio/fflush.c @@ -0,0 +1,145 @@ +/*- + * Copyright (c) 1990, 1993 + * The Regents of the University of California. All rights reserved. + * + * This code is derived from software contributed to Berkeley by + * Chris Torek. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#if defined(LIBC_SCCS) && !defined(lint) +static char sccsid[] = "@(#)fflush.c 8.1 (Berkeley) 6/4/93"; +#endif /* LIBC_SCCS and not lint */ +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include "namespace.h" +#include <errno.h> +#include <stdio.h> +#include "un-namespace.h" +#include "libc_private.h" +#include "local.h" + +static int sflush_locked(FILE *); + +/* + * Flush a single file, or (if fp is NULL) all files. + * MT-safe version + */ +int +fflush(FILE *fp) +{ + int retval; + + if (fp == NULL) + return (_fwalk(sflush_locked)); + FLOCKFILE(fp); + + /* + * There is disagreement about the correct behaviour of fflush() + * when passed a file which is not open for reading. According to + * the ISO C standard, the behaviour is undefined. + * Under linux, such an fflush returns success and has no effect; + * under Windows, such an fflush is documented as behaving instead + * as fpurge(). + * Given that applications may be written with the expectation of + * either of these two behaviours, the only safe (non-astonishing) + * option is to return EBADF and ask that applications be fixed. + */ + if ((fp->_flags & (__SWR | __SRW)) == 0) { + errno = EBADF; + retval = EOF; + } else + retval = __sflush(fp); + FUNLOCKFILE(fp); + return (retval); +} + +/* + * Flush a single file, or (if fp is NULL) all files. + * Non-MT-safe version + */ +int +__fflush(FILE *fp) +{ + int retval; + + if (fp == NULL) + return (_fwalk(sflush_locked)); + if ((fp->_flags & (__SWR | __SRW)) == 0) { + errno = EBADF; + retval = EOF; + } else + retval = __sflush(fp); + return (retval); +} + +int +__sflush(FILE *fp) +{ + unsigned char *p; + int n, t; + + t = fp->_flags; + if ((t & __SWR) == 0) + return (0); + + if ((p = fp->_bf._base) == NULL) + return (0); + + n = fp->_p - p; /* write this much */ + + /* + * Set these immediately to avoid problems with longjmp and to allow + * exchange buffering (via setvbuf) in user write function. + */ + fp->_p = p; + fp->_w = t & (__SLBF|__SNBF) ? 0 : fp->_bf._size; + + for (; n > 0; n -= t, p += t) { + t = _swrite(fp, (char *)p, n); + if (t <= 0) { + fp->_flags |= __SERR; + return (EOF); + } + } + return (0); +} + +static int +sflush_locked(FILE *fp) +{ + int ret; + + FLOCKFILE(fp); + ret = __sflush(fp); + FUNLOCKFILE(fp); + return (ret); +} |
