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 37 #if defined(LIBC_SCCS) && !defined(lint) 38 static char rcsid[] = "$OpenBSD: snprintf.c,v 1.6 1998/01/12 06:20:56 millert Exp $"; 39 #endif /* LIBC_SCCS and not lint */ 40 41 #include <limits.h> 42 #include <stdio.h> 43 #ifdef __STDC__ 44 #include <stdarg.h> 45 #else 46 #include <varargs.h> 47 #endif 48 49 int 50 #ifdef __STDC__ 51 snprintf(char *str, size_t n, char const *fmt, ...) 52 #else 53 snprintf(str, n, fmt, va_alist) 54 char *str; 55 size_t n; 56 char *fmt; 57 va_dcl 58 #endif 59 { 60 int ret; 61 va_list ap; 62 FILE f; 63 64 /* While snprintf(3) specifies size_t stdio uses an int internally */ 65 if (n > INT_MAX) 66 n = INT_MAX; 67 #ifdef __STDC__ 68 va_start(ap, fmt); 69 #else 70 va_start(ap); 71 #endif 72 f._file = -1; 73 f._flags = __SWR | __SSTR; 74 f._bf._base = f._p = (unsigned char *)str; 75 f._bf._size = f._w = n ? n - 1 : 0; 76 ret = vfprintf(&f, fmt, ap); 77 if (n) 78 *f._p = '\0'; 79 va_end(ap); 80 return (ret); 81 } 82