stdio.subproj/stdio.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * Copyright (c) 1990, 1993
  24  *      The Regents of the University of California.  All rights reserved.
  25  *
  26  * This code is derived from software contributed to Berkeley by
  27  * Chris Torek.
  28  *
  29  * Redistribution and use in source and binary forms, with or without
  30  * modification, are permitted provided that the following conditions
  31  * are met:
  32  * 1. Redistributions of source code must retain the above copyright
  33  *    notice, this list of conditions and the following disclaimer.
  34  * 2. Redistributions in binary form must reproduce the above copyright
  35  *    notice, this list of conditions and the following disclaimer in the
  36  *    documentation and/or other materials provided with the distribution.
  37  * 3. All advertising materials mentioning features or use of this software
  38  *    must display the following acknowledgement:
  39  *      This product includes software developed by the University of
  40  *      California, Berkeley and its contributors.
  41  * 4. Neither the name of the University nor the names of its contributors
  42  *    may be used to endorse or promote products derived from this software
  43  *    without specific prior written permission.
  44  *
  45  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  46  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  47  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  48  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  49  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  50  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  51  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  52  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  53  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  54  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  55  * SUCH DAMAGE.
  56  */
  57
  58
  59 #include <fcntl.h>
  60 #include <unistd.h>
  61 #include <stdio.h>
  62 #include "local.h"
  63
  64 /*
  65  * Small standard I/O/seek/close functions.
  66  * These maintain the `known seek offset' for seek optimisation.
  67  */
  68 int
  69 __sread(cookie, buf, n)
  70         void *cookie;
  71         char *buf;
  72         int n;
  73 {
  74         register FILE *fp = cookie;
  75         register int ret;
  76
  77         ret = read(fp->_file, buf, n);
  78         /* if the read succeeded, update the current offset */
  79         if (ret >= 0)
  80                 fp->_offset += ret;
  81         else
  82                 fp->_flags &= ~__SOFF;  /* paranoia */
  83         return (ret);
  84 }
  85
  86 int
  87 __swrite(cookie, buf, n)
  88         void *cookie;
  89         char const *buf;
  90         int n;
  91 {
  92         register FILE *fp = cookie;
  93
  94         if (fp->_flags & __SAPP)
  95                 (void) lseek(fp->_file, (off_t)0, SEEK_END);
  96         fp->_flags &= ~__SOFF;  /* in case FAPPEND mode is set */
  97         return (write(fp->_file, buf, n));
  98 }
  99
 100 fpos_t
 101 __sseek(cookie, offset, whence)
 102         void *cookie;
 103         fpos_t offset;
 104         int whence;
 105 {
 106         register FILE *fp = cookie;
 107         register off_t ret;
 108
 109         ret = lseek(fp->_file, (off_t)offset, whence);
 110         if (ret == -1L)
 111                 fp->_flags &= ~__SOFF;
 112         else {
 113                 fp->_flags |= __SOFF;
 114                 fp->_offset = ret;
 115         }
 116         return (ret);
 117 }
 118
 119 int
 120 __sclose(cookie)
 121         void *cookie;
 122 {
 123
 124         return (close(((FILE *)cookie)->_file));
 125 }