xref: /onnv-gate/usr/src/lib/libbc/libc/stdio/common/fwrite.c (revision 0:68f95e015346)
1*0Sstevel@tonic-gate /*
2*0Sstevel@tonic-gate  * CDDL HEADER START
3*0Sstevel@tonic-gate  *
4*0Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*0Sstevel@tonic-gate  * Common Development and Distribution License, Version 1.0 only
6*0Sstevel@tonic-gate  * (the "License").  You may not use this file except in compliance
7*0Sstevel@tonic-gate  * with the License.
8*0Sstevel@tonic-gate  *
9*0Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10*0Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
11*0Sstevel@tonic-gate  * See the License for the specific language governing permissions
12*0Sstevel@tonic-gate  * and limitations under the License.
13*0Sstevel@tonic-gate  *
14*0Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
15*0Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16*0Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
17*0Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
18*0Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
19*0Sstevel@tonic-gate  *
20*0Sstevel@tonic-gate  * CDDL HEADER END
21*0Sstevel@tonic-gate  */
22*0Sstevel@tonic-gate /*
23*0Sstevel@tonic-gate  * Copyright 1989 Sun Microsystems, Inc.  All rights reserved.
24*0Sstevel@tonic-gate  * Use is subject to license terms.
25*0Sstevel@tonic-gate  */
26*0Sstevel@tonic-gate 
27*0Sstevel@tonic-gate /*      Copyright (c) 1984 AT&T */
28*0Sstevel@tonic-gate /*        All Rights Reserved   */
29*0Sstevel@tonic-gate 
30*0Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"  /* from S5R2 3.6 */
31*0Sstevel@tonic-gate 
32*0Sstevel@tonic-gate /*LINTLIBRARY*/
33*0Sstevel@tonic-gate /*
34*0Sstevel@tonic-gate  * This version writes directly to the buffer rather than looping on putc.
35*0Sstevel@tonic-gate  * Ptr args aren't checked for NULL because the program would be a
36*0Sstevel@tonic-gate  * catastrophic mess anyway.  Better to abort than just to return NULL.
37*0Sstevel@tonic-gate  *
38*0Sstevel@tonic-gate  * This version does buffered writes larger than BUFSIZ directly, when
39*0Sstevel@tonic-gate  * the buffer is empty.
40*0Sstevel@tonic-gate  */
41*0Sstevel@tonic-gate #include <stdio.h>
42*0Sstevel@tonic-gate #include "stdiom.h"
43*0Sstevel@tonic-gate 
44*0Sstevel@tonic-gate #define MIN(x, y)       (x < y ? x : y)
45*0Sstevel@tonic-gate 
46*0Sstevel@tonic-gate extern char *memcpy();
47*0Sstevel@tonic-gate 
48*0Sstevel@tonic-gate int
fwrite(ptr,size,count,iop)49*0Sstevel@tonic-gate fwrite(ptr, size, count, iop)
50*0Sstevel@tonic-gate char *ptr;
51*0Sstevel@tonic-gate int size, count;
52*0Sstevel@tonic-gate register FILE *iop;
53*0Sstevel@tonic-gate {
54*0Sstevel@tonic-gate 	register unsigned nleft;
55*0Sstevel@tonic-gate 	register int n;
56*0Sstevel@tonic-gate 	register unsigned char *cptr, *bufend;
57*0Sstevel@tonic-gate 	register unsigned char *prev_ptr;
58*0Sstevel@tonic-gate 
59*0Sstevel@tonic-gate 	if (size <= 0 || count <= 0 || _WRTCHK(iop))
60*0Sstevel@tonic-gate 	        return (0);
61*0Sstevel@tonic-gate 
62*0Sstevel@tonic-gate 	bufend = iop->_base + iop->_bufsiz;
63*0Sstevel@tonic-gate 	nleft = count*size;
64*0Sstevel@tonic-gate 
65*0Sstevel@tonic-gate 	/* if the file is unbuffered, or if the iop->ptr = iop->base, and there
66*0Sstevel@tonic-gate 	   is > BUFSZ chars to write, we can do a direct write */
67*0Sstevel@tonic-gate 	prev_ptr = iop->_ptr;
68*0Sstevel@tonic-gate 	if (iop->_base >= iop->_ptr)  {	/*this covers the unbuffered case, too*/
69*0Sstevel@tonic-gate 		if (((iop->_flag & _IONBF) != 0) || (nleft >= BUFSIZ))  {
70*0Sstevel@tonic-gate 			if ((n=write(fileno(iop),ptr,nleft)) != nleft)
71*0Sstevel@tonic-gate 			    {
72*0Sstevel@tonic-gate 				iop->_flag |= _IOERR;
73*0Sstevel@tonic-gate 				n = (n >= 0) ? n : 0;
74*0Sstevel@tonic-gate 			}
75*0Sstevel@tonic-gate 			return n/size;
76*0Sstevel@tonic-gate 		}
77*0Sstevel@tonic-gate 	}
78*0Sstevel@tonic-gate 	/* Put characters in the buffer */
79*0Sstevel@tonic-gate 	/* note that the meaning of n when just starting this loop is
80*0Sstevel@tonic-gate 	   irrelevant.  It is defined in the loop */
81*0Sstevel@tonic-gate 	for (; ; ptr += n) {
82*0Sstevel@tonic-gate 	        while ((n = bufend - (cptr = iop->_ptr)) <= 0)  /* full buf */
83*0Sstevel@tonic-gate 	                if (_xflsbuf(iop) == EOF)
84*0Sstevel@tonic-gate 	                        return (count - (nleft + size - 1)/size);
85*0Sstevel@tonic-gate 	        n = MIN(nleft, n);
86*0Sstevel@tonic-gate 	        (void) memcpy((char *) cptr, ptr, n);
87*0Sstevel@tonic-gate 	        iop->_cnt -= n;
88*0Sstevel@tonic-gate 	        iop->_ptr += n;
89*0Sstevel@tonic-gate 	        _BUFSYNC(iop);
90*0Sstevel@tonic-gate 		/* done; flush if linebuffered with a newline */
91*0Sstevel@tonic-gate 	        if ((nleft -= n) == 0)  {
92*0Sstevel@tonic-gate 			if (iop->_flag & (_IOLBF | _IONBF)) {
93*0Sstevel@tonic-gate 	               		if ((iop->_flag & _IONBF) || (memchr(prev_ptr,
94*0Sstevel@tonic-gate 					'\n',iop->_ptr - prev_ptr) != NULL))  {
95*0Sstevel@tonic-gate 				     	(void) _xflsbuf(iop);
96*0Sstevel@tonic-gate 				}
97*0Sstevel@tonic-gate 			}
98*0Sstevel@tonic-gate 	                return (count);
99*0Sstevel@tonic-gate 	        }
100*0Sstevel@tonic-gate 	}
101*0Sstevel@tonic-gate }
102