refill.c
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上传日期:2007-01-17
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- /* refill.c - file for stdio.h */
- /* Copyright 1992 Wind River Systems, Inc. */
- /*
- modification history
- --------------------
- 01b,20sep92,smb documentation additions
- 01a,29jul92,jcf Flush only the current fp.
- +smb taken from UCB stdio
- */
- /*
- DESCRIPTION
- * Copyright (c) 1990 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.
- INCLUDE FILE: stdio.h, error.h, stdlib.h
- SEE ALSO: American National Standard X3.159-1989
- NOMANUAL
- */
- #include "vxWorks.h"
- #include "stdio.h"
- #include "errno.h"
- #include "stdlib.h"
- #include "private/stdioP.h"
- /******************************************************************************
- *
- * lflush - internal routine.
- *
- * INCLUDE: stdio.h
- *
- * RETURNS:
- * NOMANUAL
- */
- LOCAL int lflush
- (
- FILE *fp
- )
- {
- if ((fp->_flags & (__SLBF | __SWR)) == (__SLBF | __SWR))
- return (__sflush (fp));
- return (0);
- }
- /******************************************************************************
- *
- * __srefill - refill a stdio buffer.
- *
- * INCLUDE: stdio.h
- *
- * RETURNS: EOF on eof or error, 0 otherwise.
- * NOMANUAL
- */
- int __srefill
- (
- FAST FILE *fp
- )
- {
- fp->_r = 0; /* largely a convenience for callers */
- /* SysV does not make this test; take it out for compatibility */
- if (fp->_flags & __SEOF)
- return (EOF);
- /* if not already reading, have to be reading and writing */
- if ((fp->_flags & __SRD) == 0)
- {
- if ((fp->_flags & __SRW) == 0)
- {
- errno = EBADF;
- return (EOF);
- }
- if (fp->_flags & __SWR) /* switch to reading */
- {
- if (__sflush (fp))
- return (EOF);
- fp->_flags &= ~__SWR;
- fp->_w = 0;
- fp->_lbfsize = 0;
- }
- fp->_flags |= __SRD;
- }
- else
- {
- /*
- * We were reading. If there is an ungetc buffer,
- * we must have been reading from that. Drop it,
- * restoring the previous buffer (if any). If there
- * is anything in that buffer, return.
- */
- if (HASUB(fp))
- {
- FREEUB(fp);
- if ((fp->_r = fp->_ur) != 0)
- {
- fp->_p = fp->_up;
- return (0);
- }
- }
- }
- if (fp->_bf._base == NULL)
- __smakebuf (fp);
- /*
- * Before reading from a line buffered or unbuffered file,
- * flush all line buffered output files, per the ANSI C
- * standard.
- */
- if (fp->_flags & (__SLBF|__SNBF))
- lflush(fp); /* flush at least current fp */
- /* XXX lflush(stdin); Someday we could flush these */
- /* XXX lflush(stdout); Someday we could flush these */
- /* XXX lflush(stderr); Someday we could flush these */
- fp->_p = fp->_bf._base;
- fp->_r = __sread (fp, (char *)fp->_p, fp->_bf._size);
- fp->_flags &= ~__SMOD; /* buffer contents are again pristine */
- if (fp->_r <= 0)
- {
- if (fp->_r == 0)
- fp->_flags |= __SEOF;
- else
- {
- fp->_r = 0;
- fp->_flags |= __SERR;
- }
- return (EOF);
- }
- return (0);
- }