stdio/stdio.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*
  26  * Copyright (c) 1990, 1993
  27  *      The Regents of the University of California.  All rights reserved.
  28  *
  29  * This code is derived from software contributed to Berkeley by
  30  * Chris Torek.
  31  *
  32  * Redistribution and use in source and binary forms, with or without
  33  * modification, are permitted provided that the following conditions
  34  * are met:
  35  * 1. Redistributions of source code must retain the above copyright
  36  *    notice, this list of conditions and the following disclaimer.
  37  * 2. Redistributions in binary form must reproduce the above copyright
  38  *    notice, this list of conditions and the following disclaimer in the
  39  *    documentation and/or other materials provided with the distribution.
  40  * 3. All advertising materials mentioning features or use of this software
  41  *    must display the following acknowledgement:
  42  *      This product includes software developed by the University of
  43  *      California, Berkeley and its contributors.
  44  * 4. Neither the name of the University nor the names of its contributors
  45  *    may be used to endorse or promote products derived from this software
  46  *    without specific prior written permission.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  58  * SUCH DAMAGE.
  59  */
  60
  61
  62 #include <fcntl.h>
  63 #include <unistd.h>
  64 #include <stdio.h>
  65 #include "local.h"
  66
  67 /*
  68  * Small standard I/O/seek/close functions.
  69  * These maintain the `known seek offset' for seek optimisation.
  70  */
  71 int
  72 __sread(cookie, buf, n)
  73         void *cookie;
  74         char *buf;
  75         int n;
  76 {
  77         register FILE *fp = cookie;
  78         register int ret;
  79
  80         ret = read(fp->_file, buf, n);
  81         /* if the read succeeded, update the current offset */
  82         if (ret >= 0)
  83                 fp->_offset += ret;
  84         else
  85                 fp->_flags &= ~__SOFF;  /* paranoia */
  86         return (ret);
  87 }
  88
  89 int
  90 __swrite(cookie, buf, n)
  91         void *cookie;
  92         char const *buf;
  93         int n;
  94 {
  95         register FILE *fp = cookie;
  96
  97         if (fp->_flags & __SAPP)
  98                 (void) lseek(fp->_file, (off_t)0, SEEK_END);
  99         fp->_flags &= ~__SOFF;  /* in case FAPPEND mode is set */
 100         return (write(fp->_file, buf, n));
 101 }
 102
 103 fpos_t
 104 __sseek(cookie, offset, whence)
 105         void *cookie;
 106         fpos_t offset;
 107         int whence;
 108 {
 109         register FILE *fp = cookie;
 110         register off_t ret;
 111
 112         ret = lseek(fp->_file, (off_t)offset, whence);
 113         if (ret == -1L)
 114                 fp->_flags &= ~__SOFF;
 115         else {
 116                 fp->_flags |= __SOFF;
 117                 fp->_offset = ret;
 118         }
 119         return (ret);
 120 }
 121
 122 int
 123 __sclose(cookie)
 124         void *cookie;
 125 {
 126
 127         return (close(((FILE *)cookie)->_file));
 128 }