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stdio.c revision 1.12 
      1 /*	$NetBSD: stdio.c,v 1.12 2003/01/18 11:29:58 thorpej 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 1.12 2003/01/18 11:29:58 thorpej 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 "reentrant.h"
     57 #include "local.h"
     58 
     59 /*
     60  * Small standard I/O/seek/close functions.
     61  * These maintain the `known seek offset' for seek optimisation.
     62  */
     63 int
     64 __sread(cookie, buf, n)
     65 	void *cookie;
     66 	char *buf;
     67 	int n;
     68 {
     69 	FILE *fp = cookie;
     70 	int ret;
     71 
     72 	_DIAGASSERT(fp != NULL);
     73 	_DIAGASSERT(buf != NULL);
     74 
     75 	ret = read(fp->_file, buf, (size_t)n);
     76 	/* if the read succeeded, update the current offset */
     77 	if (ret >= 0)
     78 		fp->_offset += ret;
     79 	else
     80 		fp->_flags &= ~__SOFF;	/* paranoia */
     81 	return (ret);
     82 }
     83 
     84 int
     85 __swrite(cookie, buf, n)
     86 	void *cookie;
     87 	char const *buf;
     88 	int n;
     89 {
     90 	FILE *fp = cookie;
     91 
     92 	_DIAGASSERT(cookie != NULL);
     93 	_DIAGASSERT(buf != NULL);
     94 
     95 	if (fp->_flags & __SAPP)
     96 		(void) lseek(fp->_file, (off_t)0, SEEK_END);
     97 	fp->_flags &= ~__SOFF;	/* in case FAPPEND mode is set */
     98 	return (write(fp->_file, buf, (size_t)n));
     99 }
    100 
    101 fpos_t
    102 __sseek(cookie, offset, whence)
    103 	void *cookie;
    104 	fpos_t offset;
    105 	int whence;
    106 {
    107 	FILE *fp = cookie;
    108 	off_t ret;
    109 
    110 	_DIAGASSERT(fp != NULL);
    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 	_DIAGASSERT(cookie != NULL);
    128 
    129 	return (close(((FILE *)cookie)->_file));
    130 }
    131