1 /*- 2 * Copyright (c) 1990, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Chris Torek. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)vsnprintf.c 8.1 (Berkeley) 6/4/93 37 * $FreeBSD: src/lib/libc/stdio/vsnprintf.c,v 1.12.2.1 2002/09/23 06:58:17 maxim Exp $ 38 * $DragonFly: src/lib/libc/stdio/vsnprintf.c,v 1.9 2008/05/15 03:59:59 dillon Exp $ 39 */ 40 41 #include <limits.h> 42 #include <stdio.h> 43 #include <stdarg.h> 44 45 #include "local.h" 46 #include "priv_stdio.h" 47 48 int 49 vsnprintf(char *str, size_t n, const char *fmt, va_list ap) 50 { 51 size_t on; 52 int ret; 53 char dummy[2]; 54 FILE f; 55 56 on = n; 57 if (n != 0) 58 n--; 59 if (n > INT_MAX) 60 n = INT_MAX; 61 /* Stdio internals do not deal correctly with zero length buffer */ 62 if (n == 0) { 63 if (on > 0) 64 *str = '\0'; 65 str = dummy; 66 n = 1; 67 } 68 f.pub._fileno = -1; 69 f.pub._flags = __SWR | __SSTR; 70 f._bf._base = f.pub._p = (unsigned char *)str; 71 f._bf._size = f.pub._w = n; 72 f._up = NULL; 73 f.fl_mutex = PTHREAD_MUTEX_INITIALIZER; 74 f.fl_owner = NULL; 75 f.fl_count = 0; 76 memset(WCIO_GET(&f), 0, sizeof(struct wchar_io_data)); 77 ret = __vfprintf(&f, fmt, ap); 78 if (on > 0) 79 *f.pub._p = '\0'; 80 return (ret); 81 } 82