xref: /onnv-gate/usr/src/lib/libc/port/print/snprintf.c (revision 6812:febeba71273d)
10Sstevel@tonic-gate /*
20Sstevel@tonic-gate  * CDDL HEADER START
30Sstevel@tonic-gate  *
40Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*6812Sraf  * Common Development and Distribution License (the "License").
6*6812Sraf  * You may not use this file except in compliance with the License.
70Sstevel@tonic-gate  *
80Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
90Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
100Sstevel@tonic-gate  * See the License for the specific language governing permissions
110Sstevel@tonic-gate  * and limitations under the License.
120Sstevel@tonic-gate  *
130Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
140Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
150Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
160Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
170Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
180Sstevel@tonic-gate  *
190Sstevel@tonic-gate  * CDDL HEADER END
200Sstevel@tonic-gate  */
21*6812Sraf 
220Sstevel@tonic-gate /*
23*6812Sraf  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
240Sstevel@tonic-gate  * Use is subject to license terms.
250Sstevel@tonic-gate  */
260Sstevel@tonic-gate 
270Sstevel@tonic-gate /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
280Sstevel@tonic-gate /*	  All Rights Reserved	*/
290Sstevel@tonic-gate 
300Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
310Sstevel@tonic-gate 
32*6812Sraf #include "lint.h"
330Sstevel@tonic-gate #include <mtlib.h>
340Sstevel@tonic-gate #include <stdarg.h>
350Sstevel@tonic-gate #include <values.h>
360Sstevel@tonic-gate #include <thread.h>
370Sstevel@tonic-gate #include <synch.h>
380Sstevel@tonic-gate #include <errno.h>
390Sstevel@tonic-gate #include <sys/types.h>
400Sstevel@tonic-gate #include "print.h"
410Sstevel@tonic-gate #include "libc.h"
420Sstevel@tonic-gate 
430Sstevel@tonic-gate /*VARARGS2*/
440Sstevel@tonic-gate int
snprintf(char * string,size_t n,const char * format,...)450Sstevel@tonic-gate snprintf(char *string, size_t n, const char *format, ...)
460Sstevel@tonic-gate {
470Sstevel@tonic-gate 	ssize_t count;
480Sstevel@tonic-gate 	FILE siop;
490Sstevel@tonic-gate 	va_list ap;
500Sstevel@tonic-gate 	size_t	max = MAXINT;
510Sstevel@tonic-gate 	unsigned char tmpbuf[1]; /* dummy buffer for _doprnt() if NULL string */
520Sstevel@tonic-gate 
530Sstevel@tonic-gate 	siop._cnt = n - 1;
540Sstevel@tonic-gate 	siop._base = siop._ptr = (unsigned char *)string;
550Sstevel@tonic-gate 	siop._flag = _IOREAD;   /* distinguish dummy file descriptor */
560Sstevel@tonic-gate #ifdef _LP64
570Sstevel@tonic-gate 	/*
580Sstevel@tonic-gate 	 * _bufend() (_realbufend()) should return NULL for v/snprintf,
590Sstevel@tonic-gate 	 * so PUT() macro in _doprnt() will bounds check.  For 32-bit,
600Sstevel@tonic-gate 	 * there is no _end field, and _realbufend() will return NULL
610Sstevel@tonic-gate 	 * since it cannot find the dummy FILE structure in the linked
620Sstevel@tonic-gate 	 * list of FILE strucutres.  See bug 4274368.
630Sstevel@tonic-gate 	 */
640Sstevel@tonic-gate 	siop._end = NULL;
650Sstevel@tonic-gate #endif	/* _LP64 */
660Sstevel@tonic-gate 
670Sstevel@tonic-gate 	if (n == 0) {
680Sstevel@tonic-gate 		/*
690Sstevel@tonic-gate 		 * When n==0, string may be NULL, so always use tmpbuf to
700Sstevel@tonic-gate 		 * guard for this case.  No bytes should be transmitted to
710Sstevel@tonic-gate 		 * the buffer when n==0, so using tmpbuf instead of string
720Sstevel@tonic-gate 		 * (ie, if string is not NULL) should not matter.
730Sstevel@tonic-gate 		 */
740Sstevel@tonic-gate 		siop._base = siop._ptr = tmpbuf;
750Sstevel@tonic-gate 		siop._cnt = 0;
760Sstevel@tonic-gate 	} else if (n > max) {
770Sstevel@tonic-gate 		errno = EOVERFLOW;
780Sstevel@tonic-gate 		return (EOF);
790Sstevel@tonic-gate 	}
800Sstevel@tonic-gate 
810Sstevel@tonic-gate 	va_start(ap, format);
820Sstevel@tonic-gate 	count = _ndoprnt(format, ap, &siop, 0);
830Sstevel@tonic-gate 	va_end(ap);
840Sstevel@tonic-gate 
850Sstevel@tonic-gate 	*siop._ptr = '\0';   /* plant terminating null character */
860Sstevel@tonic-gate 
870Sstevel@tonic-gate 	if (count == EOF)
880Sstevel@tonic-gate 		return (EOF);
890Sstevel@tonic-gate 
900Sstevel@tonic-gate 	/* overflow check */
910Sstevel@tonic-gate 	if ((size_t)count > max) {
920Sstevel@tonic-gate 		errno = EOVERFLOW;
930Sstevel@tonic-gate 		return (EOF);
940Sstevel@tonic-gate 	} else {
950Sstevel@tonic-gate 		return ((int)count);
960Sstevel@tonic-gate 	}
970Sstevel@tonic-gate }
980Sstevel@tonic-gate 
990Sstevel@tonic-gate #ifndef _LP64
1000Sstevel@tonic-gate 
1010Sstevel@tonic-gate /*
1020Sstevel@tonic-gate  * 32-bit shadow function of snprintf().
1030Sstevel@tonic-gate  * When using the c89 compiler to build 32-bit applications, the size
1040Sstevel@tonic-gate  * of intmax_t is 32-bits, otherwise the size of intmax_t is 64-bits.
1050Sstevel@tonic-gate  * The shadow function uses 32-bit size of intmax_t for %j conversion.
1060Sstevel@tonic-gate  * The #pragma redefine_extname in <stdio.h> selects the proper routine
1070Sstevel@tonic-gate  * at compile time for the user application.
1080Sstevel@tonic-gate  * NOTE: this function is only available in the 32-bit library.
1090Sstevel@tonic-gate  */
1100Sstevel@tonic-gate 
1110Sstevel@tonic-gate int
_snprintf_c89(char * string,size_t n,const char * format,...)1120Sstevel@tonic-gate _snprintf_c89(char *string, size_t n, const char *format, ...)
1130Sstevel@tonic-gate {
1140Sstevel@tonic-gate 	ssize_t count;
1150Sstevel@tonic-gate 	va_list ap;
1160Sstevel@tonic-gate 
1170Sstevel@tonic-gate 	va_start(ap, format);
1180Sstevel@tonic-gate 	count = _vsnprintf_c89(string, n, format, ap);
1190Sstevel@tonic-gate 	va_end(ap);
1200Sstevel@tonic-gate 	return ((int)count);
1210Sstevel@tonic-gate }
1220Sstevel@tonic-gate 
1230Sstevel@tonic-gate #endif	/* _LP64 */
124