libdarwin/stdio.c

   1 /*
   2  * Copyright (c) 2018 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 #include "internal.h"
  24
  25 #pragma mark API
  26 size_t
  27 zsnprintf_np(char *buff, size_t len, const char *fmt, ...)
  28 {
  29         int np = 0;
  30         va_list ap;
  31
  32         va_start(ap, fmt);
  33         np = vsnprintf(buff, len, fmt, ap);
  34         va_end(ap);
  35
  36         if (np < 0) {
  37                 np = 0;
  38         } else if ((size_t)np >= len) {
  39                 np = (int)len - 1;
  40         }
  41
  42         return (size_t)np;
  43 }