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stdio.c revision 1.5 
      1 /*	$NetBSD: stdio.c,v 1.5 1996/03/29 23:29:25 jtc 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 #if defined(LIBC_SCCS) && !defined(lint)
     40 #if 0
     41 static char sccsid[] = "@(#)stdio.c	8.1 (Berkeley) 6/4/93";
     42 #endif
     43 static char rcsid[] = "$NetBSD: stdio.c,v 1.5 1996/03/29 23:29:25 jtc Exp $";
     44 #endif /* LIBC_SCCS and not lint */
     45 
     46 #include <fcntl.h>
     47 #include <unistd.h>
     48 #include <stdio.h>
     49 #include "local.h"
     50 
     51 /*
     52  * Small standard I/O/seek/close functions.
     53  * These maintain the `known seek offset' for seek optimisation.
     54  */
     55 int
     56 __sread(cookie, buf, n)
     57 	void *cookie;
     58 	char *buf;
     59 	int n;
     60 {
     61 	register FILE *fp = cookie;
     62 	register int ret;
     63 
     64 	ret = read(fp->_file, buf, n);
     65 	/* if the read succeeded, update the current offset */
     66 	if (ret >= 0)
     67 		fp->_offset += ret;
     68 	else
     69 		fp->_flags &= ~__SOFF;	/* paranoia */
     70 	return (ret);
     71 }
     72 
     73 int
     74 __swrite(cookie, buf, n)
     75 	void *cookie;
     76 	char const *buf;
     77 	int n;
     78 {
     79 	register FILE *fp = cookie;
     80 
     81 	if (fp->_flags & __SAPP)
     82 		(void) lseek(fp->_file, (off_t)0, SEEK_END);
     83 	fp->_flags &= ~__SOFF;	/* in case FAPPEND mode is set */
     84 	return (write(fp->_file, buf, n));
     85 }
     86 
     87 fpos_t
     88 __sseek(cookie, offset, whence)
     89 	void *cookie;
     90 	fpos_t offset;
     91 	int whence;
     92 {
     93 	register FILE *fp = cookie;
     94 	register off_t ret;
     95 
     96 	ret = lseek(fp->_file, (off_t)offset, whence);
     97 	if (ret == -1L)
     98 		fp->_flags &= ~__SOFF;
     99 	else {
    100 		fp->_flags |= __SOFF;
    101 		fp->_offset = ret;
    102 	}
    103 	return (ret);
    104 }
    105 
    106 int
    107 __sclose(cookie)
    108 	void *cookie;
    109 {
    110 
    111 	return (close(((FILE *)cookie)->_file));
    112 }
    113