1 /*********************************************************************** 2 * * 3 * This software is part of the ast package * 4 * Copyright (c) 1985-2007 AT&T Knowledge Ventures * 5 * and is licensed under the * 6 * Common Public License, Version 1.0 * 7 * by AT&T Knowledge Ventures * 8 * * 9 * A copy of the License is available at * 10 * http://www.opensource.org/licenses/cpl1.0.txt * 11 * (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) * 12 * * 13 * Information and Software Systems Research * 14 * AT&T Research * 15 * Florham Park NJ * 16 * * 17 * Glenn Fowler <gsf@research.att.com> * 18 * David Korn <dgk@research.att.com> * 19 * Phong Vo <kpv@research.att.com> * 20 * * 21 ***********************************************************************/ 22 #pragma prototyped 23 24 #include "stdhdr.h" 25 26 int 27 vsnprintf(char* s, int n, const char* fmt, va_list args) 28 { 29 Sfio_t f; 30 int v; 31 32 if (!s) 33 return -1; 34 35 /* 36 * make a fake stream 37 */ 38 39 SFCLEAR(&f, NiL); 40 f.flags = SF_STRING|SF_WRITE; 41 f.bits = SF_PRIVATE; 42 f.mode = SF_WRITE; 43 f.size = n - 1; 44 f.data = f.next = f.endr = (uchar*)s; 45 f.endb = f.endw = f.data + f.size; 46 47 /* 48 * call and fix up 49 */ 50 51 v = sfvprintf(&f, fmt, args); 52 *f.next = 0; 53 _Sfi = f.next - f.data; 54 return v; 55 } 56