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stdio.c revision 1.10 
      1 /*	$NetBSD: stdio.c,v 1.10 1999/09/16 11:45:31 lukem Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1990, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * This code is derived from software contributed to Berkeley by
      8  * Chris Torek.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *	This product includes software developed by the University of
     21  *	California, Berkeley and its contributors.
     22  * 4. Neither the name of the University nor the names of its contributors
     23  *    may be used to endorse or promote products derived from this software
     24  *    without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     36  * SUCH DAMAGE.
     37  */
     38 
     39 #include <sys/cdefs.h>
     40 #if defined(LIBC_SCCS) && !defined(lint)
     41 #if 0
     42 static char sccsid[] = "@(#)stdio.c	8.1 (Berkeley) 6/4/93";
     43 #else
     44 __RCSID("$NetBSD: stdio.c,v 1.10 1999/09/16 11:45:31 lukem Exp $");
     45 #endif
     46 #endif /* LIBC_SCCS and not lint */
     47 
     48 #include "namespace.h"
     49 
     50 #include <assert.h>
     51 #include <errno.h>
     52 #include <fcntl.h>
     53 #include <stdio.h>
     54 #include <unistd.h>
     55 
     56 #include "local.h"
     57 
     58 /*
     59  * Small standard I/O/seek/close functions.
     60  * These maintain the `known seek offset' for seek optimisation.
     61  */
     62 int
     63 __sread(cookie, buf, n)
     64 	void *cookie;
     65 	char *buf;
     66 	int n;
     67 {
     68 	FILE *fp = cookie;
     69 	int ret;
     70 
     71 	_DIAGASSERT(fp != NULL);
     72 	_DIAGASSERT(buf != NULL);
     73 #ifdef _DIAGNOSTIC
     74 	if (fp == NULL) {
     75 		errno = EBADF;
     76 		return (-1);
     77 	}
     78 	if (buf == NULL) {
     79 		errno = EFAULT;
     80 		return (-1);
     81 	}
     82 #endif
     83 
     84 	ret = read(fp->_file, buf, (size_t)n);
     85 	/* if the read succeeded, update the current offset */
     86 	if (ret >= 0)
     87 		fp->_offset += ret;
     88 	else
     89 		fp->_flags &= ~__SOFF;	/* paranoia */
     90 	return (ret);
     91 }
     92 
     93 int
     94 __swrite(cookie, buf, n)
     95 	void *cookie;
     96 	char const *buf;
     97 	int n;
     98 {
     99 	FILE *fp = cookie;
    100 
    101 	_DIAGASSERT(cookie != NULL);
    102 	_DIAGASSERT(buf != NULL);
    103 #ifdef _DIAGNOSTIC
    104 	if (fp == NULL) {
    105 		errno = EBADF;
    106 		return (-1);
    107 	}
    108 	if (buf == NULL) {
    109 		errno = EFAULT;
    110 		return (-1);
    111 	}
    112 #endif
    113 
    114 	if (fp->_flags & __SAPP)
    115 		(void) lseek(fp->_file, (off_t)0, SEEK_END);
    116 	fp->_flags &= ~__SOFF;	/* in case FAPPEND mode is set */
    117 	return (write(fp->_file, buf, (size_t)n));
    118 }
    119 
    120 fpos_t
    121 __sseek(cookie, offset, whence)
    122 	void *cookie;
    123 	fpos_t offset;
    124 	int whence;
    125 {
    126 	FILE *fp = cookie;
    127 	off_t ret;
    128 
    129 	_DIAGASSERT(fp != NULL);
    130 #ifdef _DIAGNOSTIC
    131 	if (fp == NULL) {
    132 		errno = EBADF;
    133 		return (-1);
    134 	}
    135 #endif
    136 
    137 	ret = lseek(fp->_file, (off_t)offset, whence);
    138 	if (ret == -1L)
    139 		fp->_flags &= ~__SOFF;
    140 	else {
    141 		fp->_flags |= __SOFF;
    142 		fp->_offset = ret;
    143 	}
    144 	return (ret);
    145 }
    146 
    147 int
    148 __sclose(cookie)
    149 	void *cookie;
    150 {
    151 
    152 	_DIAGASSERT(cookie != NULL);
    153 #ifdef _DIAGNOSTIC
    154 	if (cookie == NULL) {
    155 		errno = EBADF;
    156 		return (-1);
    157 	}
    158 #endif
    159 
    160 	return (close(((FILE *)cookie)->_file));
    161 }
    162