1 /* $NetBSD: vsnprintf.c,v 1.25 2012/03/15 18:22:31 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[] = "@(#)vsnprintf.c 8.1 (Berkeley) 6/4/93"; 39 #else 40 __RCSID("$NetBSD: vsnprintf.c,v 1.25 2012/03/15 18:22:31 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 <stdio.h> 49 #include "reentrant.h" 50 #include "local.h" 51 52 #if defined(_FORTIFY_SOURCE) && !defined(__lint__) 53 #undef vsnprintf 54 #define vsnprintf _vsnprintf 55 #endif 56 57 #ifdef __weak_alias 58 __weak_alias(vsnprintf,_vsnprintf) 59 #endif 60 61 int 62 vsnprintf(char *str, size_t n, const char *fmt, va_list ap) 63 { 64 int ret; 65 FILE f; 66 struct __sfileext fext; 67 unsigned char dummy[1]; 68 69 _DIAGASSERT(n == 0 || str != NULL); 70 _DIAGASSERT(fmt != NULL); 71 72 if ((int)n < 0) { 73 errno = EINVAL; 74 return -1; 75 } 76 77 _FILEEXT_SETUP(&f, &fext); 78 f._file = -1; 79 f._flags = __SWR | __SSTR; 80 if (n == 0) { 81 f._bf._base = f._p = dummy; 82 f._bf._size = f._w = 0; 83 } else { 84 f._bf._base = f._p = (unsigned char *)str; 85 _DIAGASSERT(__type_fit(int, n - 1)); 86 f._bf._size = f._w = (int)(n - 1); 87 } 88 ret = __vfprintf_unlocked(&f, fmt, ap); 89 *f._p = 0; 90 return ret; 91 } 92