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  * 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
  37 #if defined(LIBC_SCCS) && !defined(lint)
  38 static char sccsid[] = "@(#)stdio.c     8.1 (Berkeley) 6/4/93";
  39 #endif /* LIBC_SCCS and not lint */
  40 #include <sys/cdefs.h>
  41 __FBSDID("$FreeBSD: src/lib/libc/stdio/stdio.c,v 1.24 2003/01/07 06:17:13 tjr Exp $");
  42
  43 #include "namespace.h"
  44 #include <errno.h>
  45 #include <fcntl.h>
  46 #include <limits.h>
  47 #include <stdio.h>
  48 #include <stdlib.h>
  49 #include <unistd.h>
  50 #include "un-namespace.h"
  51 #include "local.h"
  52
  53 /*
  54  * Small standard I/O/seek/close functions.
  55  */
  56 int
  57 __sread(cookie, buf, n)
  58         void *cookie;
  59         char *buf;
  60         int n;
  61 {
  62         FILE *fp = cookie;
  63
  64         return(_read(fp->_file, buf, (size_t)n));
  65 }
  66
  67 int
  68 __swrite(cookie, buf, n)
  69         void *cookie;
  70         char const *buf;
  71         int n;
  72 {
  73         FILE *fp = cookie;
  74
  75         return (_write(fp->_file, buf, (size_t)n));
  76 }
  77
  78 fpos_t
  79 __sseek(cookie, offset, whence)
  80         void *cookie;
  81         fpos_t offset;
  82         int whence;
  83 {
  84         FILE *fp = cookie;
  85
  86         return (lseek(fp->_file, (off_t)offset, whence));
  87 }
  88
  89 int
  90 __sclose(cookie)
  91         void *cookie;
  92 {
  93
  94         return (_close(((FILE *)cookie)->_file));
  95 }
  96
  97 /*
  98  * Higher level wrappers.
  99  */
 100 int
 101 _sread(fp, buf, n)
 102         FILE *fp;
 103         char *buf;
 104         int n;
 105 {
 106         int ret;
 107
 108         ret = (*fp->_read)(fp->_cookie, buf, n);
 109         if (ret > 0) {
 110                 if (fp->_flags & __SOFF) {
 111                         if (fp->_offset <= OFF_MAX - ret)
 112                                 fp->_offset += ret;
 113                         else
 114                                 fp->_flags &= ~__SOFF;
 115                 }
 116         } else if (ret < 0)
 117                 fp->_flags &= ~__SOFF;
 118         return (ret);
 119 }
 120
 121 int
 122 _swrite(fp, buf, n)
 123         FILE *fp;
 124         char const *buf;
 125         int n;
 126 {
 127         int ret;
 128         int serrno;
 129
 130         if (fp->_flags & __SAPP) {
 131                 serrno = errno;
 132                 if (_sseek(fp, (fpos_t)0, SEEK_END) == -1 &&
 133                     (fp->_flags & __SOPT))
 134                         return (-1);
 135                 errno = serrno;
 136         }
 137         ret = (*fp->_write)(fp->_cookie, buf, n);
 138         /* __SOFF removed even on success in case O_APPEND mode is set. */
 139         if (ret >= 0) {
 140                 if ((fp->_flags & (__SAPP|__SOFF)) == (__SAPP|__SOFF) &&
 141                     fp->_offset <= OFF_MAX - ret)
 142                         fp->_offset += ret;
 143                 else
 144                         fp->_flags &= ~__SOFF;
 145
 146         } else if (ret < 0)
 147                 fp->_flags &= ~__SOFF;
 148         return (ret);
 149 }
 150
 151 fpos_t
 152 _sseek(fp, offset, whence)
 153         FILE *fp;
 154         fpos_t offset;
 155         int whence;
 156 {
 157         fpos_t ret;
 158         int serrno, errret;
 159
 160         serrno = errno;
 161         errno = 0;
 162         ret = (*fp->_seek)(fp->_cookie, offset, whence);
 163         errret = errno;
 164         if (errno == 0)
 165                 errno = serrno;
 166         /*
 167          * Disallow negative seeks per POSIX.
 168          * It is needed here to help upper level caller
 169          * in the cases it can't detect.
 170          */
 171         if (ret < 0) {
 172                 if (errret == 0) {
 173                         if (offset != 0 || whence != SEEK_CUR) {
 174                                 if (HASUB(fp))
 175                                         FREEUB(fp);
 176                                 fp->_p = fp->_bf._base;
 177                                 fp->_r = 0;
 178                                 fp->_flags &= ~__SEOF;
 179                         }
 180                         fp->_flags |= __SERR;
 181                         errno = EINVAL;
 182                 } else if (errret == ESPIPE)
 183                         fp->_flags &= ~__SAPP;
 184                 fp->_flags &= ~__SOFF;
 185                 ret = -1;
 186         } else if (fp->_flags & __SOPT) {
 187                 fp->_flags |= __SOFF;
 188                 fp->_offset = ret;
 189         }
 190         return (ret);
 191 }