stdio/FreeBSD/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  * 4. Neither the name of the University nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 #if defined(LIBC_SCCS) && !defined(lint)
  34 static char sccsid[] = "@(#)stdio.c     8.1 (Berkeley) 6/4/93";
  35 #endif /* LIBC_SCCS and not lint */
  36 #include <sys/cdefs.h>
  37 __FBSDID("$FreeBSD: src/lib/libc/stdio/stdio.c,v 1.28 2008/05/05 16:14:02 jhb Exp $");
  38
  39 #include "namespace.h"
  40 #include <errno.h>
  41 #include <fcntl.h>
  42 #include <limits.h>
  43 #include <stdio.h>
  44 #include <stdlib.h>
  45 #include <unistd.h>
  46 #include "un-namespace.h"
  47 #include "local.h"
  48
  49 /*
  50  * Small standard I/O/seek/close functions.
  51  */
  52 int
  53 __sread(cookie, buf, n)
  54         void *cookie;
  55         char *buf;
  56         int n;
  57 {
  58         FILE *fp = cookie;
  59
  60         return(_read(fp->_file, buf, (size_t)n));
  61 }
  62
  63 int
  64 __swrite(cookie, buf, n)
  65         void *cookie;
  66         char const *buf;
  67         int n;
  68 {
  69         FILE *fp = cookie;
  70
  71         return (_write(fp->_file, buf, (size_t)n));
  72 }
  73
  74 fpos_t
  75 __sseek(cookie, offset, whence)
  76         void *cookie;
  77         fpos_t offset;
  78         int whence;
  79 {
  80         FILE *fp = cookie;
  81
  82         return (lseek(fp->_file, (off_t)offset, whence));
  83 }
  84
  85 int
  86 __sclose(cookie)
  87         void *cookie;
  88 {
  89
  90         return (_close(((FILE *)cookie)->_file));
  91 }
  92
  93 /*
  94  * Higher level wrappers.
  95  */
  96 int
  97 _sread(fp, buf, n)
  98         FILE *fp;
  99         char *buf;
 100         int n;
 101 {
 102         int ret;
 103
 104         ret = (*fp->_read)(fp->_cookie, buf, n);
 105         if (ret > 0) {
 106                 if (fp->_flags & __SOFF) {
 107                         if (fp->_offset <= OFF_MAX - ret)
 108                                 fp->_offset += ret;
 109                         else
 110                                 fp->_flags &= ~__SOFF;
 111                 }
 112         } else if (ret < 0)
 113                 fp->_flags &= ~__SOFF;
 114         return (ret);
 115 }
 116
 117 int
 118 _swrite(fp, buf, n)
 119         FILE *fp;
 120         char const *buf;
 121         int n;
 122 {
 123         int ret;
 124         int serrno;
 125
 126         if (fp->_flags & __SAPP) {
 127                 serrno = errno;
 128                 if (_sseek(fp, (fpos_t)0, SEEK_END) == -1 &&
 129                     (fp->_flags & __SOPT))
 130                         return (-1);
 131                 errno = serrno;
 132         }
 133         ret = (*fp->_write)(fp->_cookie, buf, n);
 134         /* __SOFF removed even on success in case O_APPEND mode is set. */
 135         if (ret >= 0) {
 136                 if ((fp->_flags & (__SAPP|__SOFF)) == (__SAPP|__SOFF) &&
 137                     fp->_offset <= OFF_MAX - ret)
 138                         fp->_offset += ret;
 139                 else
 140                         fp->_flags &= ~__SOFF;
 141
 142         } else if (ret < 0)
 143                 fp->_flags &= ~__SOFF;
 144         return (ret);
 145 }
 146
 147 fpos_t
 148 _sseek(fp, offset, whence)
 149         FILE *fp;
 150         fpos_t offset;
 151         int whence;
 152 {
 153         fpos_t ret;
 154         int serrno, errret;
 155
 156         serrno = errno;
 157         errno = 0;
 158         ret = (*fp->_seek)(fp->_cookie, offset, whence);
 159         errret = errno;
 160         if (errno == 0)
 161                 errno = serrno;
 162         /*
 163          * Disallow negative seeks per POSIX.
 164          * It is needed here to help upper level caller
 165          * in the cases it can't detect.
 166          */
 167         if (ret < 0) {
 168                 if (errret == 0) {
 169                         if (offset != 0 || whence != SEEK_CUR) {
 170                                 if (HASUB(fp))
 171                                         FREEUB(fp);
 172                                 fp->_p = fp->_bf._base;
 173                                 fp->_r = 0;
 174                                 fp->_flags &= ~__SEOF;
 175                         }
 176                         fp->_flags |= __SERR;
 177                         errno = EINVAL;
 178                 } else if (errret == ESPIPE)
 179                         fp->_flags &= ~__SAPP;
 180                 fp->_flags &= ~__SOFF;
 181                 ret = -1;
 182         } else if (fp->_flags & __SOPT) {
 183                 fp->_flags |= __SOFF;
 184                 fp->_offset = ret;
 185         }
 186         return (ret);
 187 }