lib/libc/stdio/stdio.c

   1 /*-
   2  * Copyright (c) 1990, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * This code is derived from software contributed to Berkeley by
   6  * Chris Torek.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. All advertising materials mentioning features or use of this software
  17  *    must display the following acknowledgement:
  18  *      This product includes software developed by the University of
  19  *      California, Berkeley and its contributors.
  20  * 4. Neither the name of the University nor the names of its contributors
  21  *    may be used to endorse or promote products derived from this software
  22  *    without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  *
  36  * @(#)stdio.c  8.1 (Berkeley) 6/4/93
  37  * $FreeBSD: src/lib/libc/stdio/stdio.c,v 1.9 2000/01/27 23:06:46 jasone Exp $
  38  * $DragonFly: src/lib/libc/stdio/stdio.c,v 1.7 2005/11/20 11:07:30 swildner Exp $
  39  */
  40
  41 #include "namespace.h"
  42 #include <fcntl.h>
  43 #include <unistd.h>
  44 #include <stdio.h>
  45 #include "un-namespace.h"
  46
  47 #include "local.h"
  48 #include "priv_stdio.h"
  49
  50 /*
  51  * Small standard I/O/seek/close functions.
  52  * These maintain the `known seek offset' for seek optimisation.
  53  */
  54 int
  55 __sread(void *cookie, char *buf, int n)
  56 {
  57         FILE *fp = cookie;
  58         int ret;
  59
  60         ret = _read(fp->pub._fileno, buf, (size_t)n);
  61         /* if the read succeeded, update the current offset */
  62         if (ret >= 0)
  63                 fp->_offset += ret;
  64         else
  65                 fp->pub._flags &= ~__SOFF;      /* paranoia */
  66         return (ret);
  67 }
  68
  69 int
  70 __swrite(void *cookie, char const *buf, int n)
  71 {
  72         FILE *fp = cookie;
  73
  74         if (fp->pub._flags & __SAPP)
  75                 lseek(fp->pub._fileno, (off_t)0, SEEK_END);
  76         fp->pub._flags &= ~__SOFF;      /* in case FAPPEND mode is set */
  77         return (_write(fp->pub._fileno, buf, (size_t)n));
  78 }
  79
  80 fpos_t
  81 __sseek(void *cookie, fpos_t offset, int whence)
  82 {
  83         FILE *fp = cookie;
  84         off_t ret;
  85
  86         ret = lseek(fp->pub._fileno, (off_t)offset, whence);
  87         if (ret == -1)
  88                 fp->pub._flags &= ~__SOFF;
  89         else {
  90                 fp->pub._flags |= __SOFF;
  91                 fp->_offset = ret;
  92         }
  93         return (ret);
  94 }
  95
  96 int
  97 __sclose(void *cookie)
  98 {
  99
 100         return (_close(((FILE *)cookie)->pub._fileno));
 101 }