gonzui

    1: /*      $OpenBSD: fflush.c,v 1.8 2009/11/09 00:18:27 kurt Exp $ */
    2: /*-
    3:  * Copyright (c) 1990, 1993
    4:  *      The Regents of the University of California.  All rights reserved.
    5:  *
    6:  * This code is derived from software contributed to Berkeley by
    7:  * Chris Torek.
    8:  *
    9:  * Redistribution and use in source and binary forms, with or without
   10:  * modification, are permitted provided that the following conditions
   11:  * are met:
   12:  * 1. Redistributions of source code must retain the above copyright
   13:  *    notice, this list of conditions and the following disclaimer.
   14:  * 2. Redistributions in binary form must reproduce the above copyright
   15:  *    notice, this list of conditions and the following disclaimer in the
   16:  *    documentation and/or other materials provided with the distribution.
   17:  * 3. Neither the name of the University nor the names of its contributors
   18:  *    may be used to endorse or promote products derived from this software
   19:  *    without specific prior written permission.
   20:  *
   21:  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   22:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   23:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   24:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   25:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   26:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   27:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   28:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   29:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   30:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   31:  * SUCH DAMAGE.
   32:  */
   33: 
   34: #include <errno.h>
   35: #include <stdio.h>
   36: #include "local.h"
   37: 
   38: /* Flush a single file, or (if fp is NULL) all files.  */
   39: int
   40: fflush(FILE *fp)
   41: {
   42:         int    r;
   43: 
   44:         if (fp == NULL)
   45:                 return (_fwalk(__sflush_locked));
   46:         FLOCKFILE(fp);
   47:         if ((fp->_flags & (__SWR | __SRW)) == 0) {
   48:                 __sseterr(fp, EBADF);
   49:                 r = EOF;
   50:         } else
   51:                 r = __sflush(fp);
   52:         FUNLOCKFILE(fp);
   53:         return (r);
   54: }
   55: 
   56: int
   57: __sflush(FILE *fp)
   58: {
   59:         unsigned char *p;
   60:         int n, t;
   61: 
   62:         t = fp->_flags;
   63:         if ((t & __SWR) == 0)
   64:                 return (0);
   65: 
   66:         if ((p = fp->_bf._base) == NULL)
   67:                 return (0);
   68: 
   69:         n = fp->_p - p;                /* write this much */
   70: 
   71:         /*
   72:          * Set these immediately to avoid problems with longjmp and to allow
   73:          * exchange buffering (via setvbuf) in user write function.
   74:          */
   75:         fp->_p = p;
   76:         fp->_w = t & (__SLBF|__SNBF) ? 0 : fp->_bf._size;
   77: 
   78:         for (; n > 0; n -= t, p += t) {
   79:                 t = (*fp->_write)(fp->_cookie, (char *)p, n);
   80:                 if (t <= 0) {
   81:                         fp->_flags |= __SERR;
   82:                         return (EOF);
   83:                 }
   84:         }
   85:         return (0);
   86: }
   87: 
   88: int
   89: __sflush_locked(FILE *fp)
   90: {
   91:         int    r;
   92: 
   93:         FLOCKFILE(fp);
   94:         r = __sflush(fp);
   95:         FUNLOCKFILE(fp);
   96:         return (r);
   97: }