/* $OpenBSD: snprintf.c,v 1.14 2005/10/10 12:00:52 espie Exp $ */ /*- * Copyright (c) 1990, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * Chris Torek. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include <limits.h> #include <stdio.h> #include <string.h> #include <stdarg.h> #include "local.h" int snprintf(char *str, size_t n, const char *fmt, ...) { va_list ap; int ret; char dummy; FILE f; struct __sfileext fext; /* While snprintf(3) specifies size_t stdio uses an int internally */ if (n > INT_MAX) n = INT_MAX; /* Stdio internals do not deal correctly with zero length buffer */ if (n == 0) { str = &dummy; n = 1; } _FILEEXT_SETUP(&f, &fext); f._file = -1; f._flags = __SWR | __SSTR; f._bf._base = f._p = (unsigned char *)str; f._bf._size = f._w = n - 1; va_start(ap, fmt); ret = vfprintf(&f, fmt, ap); va_end(ap); *f._p = '\0'; return (ret); }