Home | History | Annotate | Line # | Download | only in stdio
stdio.c revision 1.18 
      1 /*	$NetBSD: stdio.c,v 1.18 2012/03/13 21:13:46 christos 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. Neither the name of the University nor the names of its contributors
     19  *    may be used to endorse or promote products derived from this software
     20  *    without specific prior written permission.
     21  *
     22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     32  * SUCH DAMAGE.
     33  */
     34 
     35 #include <sys/cdefs.h>
     36 #if defined(LIBC_SCCS) && !defined(lint)
     37 #if 0
     38 static char sccsid[] = "@(#)stdio.c	8.1 (Berkeley) 6/4/93";
     39 #else
     40 __RCSID("$NetBSD: stdio.c,v 1.18 2012/03/13 21:13:46 christos Exp $");
     41 #endif
     42 #endif /* LIBC_SCCS and not lint */
     43 
     44 #include "namespace.h"
     45 
     46 #include <assert.h>
     47 #include <errno.h>
     48 #include <fcntl.h>
     49 #include <stdio.h>
     50 #include <unistd.h>
     51 
     52 #include "reentrant.h"
     53 #include "local.h"
     54 
     55 /*
     56  * Small standard I/O/seek/close functions.
     57  * These maintain the `known seek offset' for seek optimisation.
     58  */
     59 int
     60 __sread(cookie, buf, n)
     61 	void *cookie;
     62 	char *buf;
     63 	int n;
     64 {
     65 	FILE *fp = cookie;
     66 	ssize_t ret;
     67 
     68 	_DIAGASSERT(fp != NULL);
     69 	_DIAGASSERT(buf != NULL);
     70 
     71 	ret = read(__sfileno(fp), buf, (size_t)n);
     72 	/* if the read succeeded, update the current offset */
     73 	if (ret >= 0)
     74 		fp->_offset += ret;
     75 	else
     76 		fp->_flags &= ~__SOFF;	/* paranoia */
     77 
     78 	return (int)ret;
     79 }
     80 
     81 int
     82 __swrite(cookie, buf, n)
     83 	void *cookie;
     84 	char const *buf;
     85 	int n;
     86 {
     87 	FILE *fp = cookie;
     88 
     89 	_DIAGASSERT(cookie != NULL);
     90 	_DIAGASSERT(buf != NULL);
     91 
     92 	if (fp->_flags & __SAPP)
     93 		(void) lseek(__sfileno(fp), (off_t)0, SEEK_END);
     94 	fp->_flags &= ~__SOFF;	/* in case FAPPEND mode is set */
     95 	return (int)write(__sfileno(fp), buf, (size_t)n);
     96 }
     97 
     98 off_t
     99 __sseek(cookie, offset, whence)
    100 	void *cookie;
    101 	off_t offset;
    102 	int whence;
    103 {
    104 	FILE *fp = cookie;
    105 	off_t ret;
    106 
    107 	_DIAGASSERT(fp != NULL);
    108 
    109 	ret = lseek(__sfileno(fp), 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 	_DIAGASSERT(cookie != NULL);
    125 
    126 	return close(__sfileno((FILE *)cookie));
    127 }
    128