safec  2.1
Safe C Library - ISO TR24731 Bounds Checking Interface
strnterminate_s.c
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1 /*------------------------------------------------------------------
2  * strnterminate_s.c
3  *
4  * February 2011, Bo Berry
5  *
6  * Copyright (c) 2011 by Cisco Systems, Inc
7  * All rights reserved.
8  *
9  * Permission is hereby granted, free of charge, to any person
10  * obtaining a copy of this software and associated documentation
11  * files (the "Software"), to deal in the Software without
12  * restriction, including without limitation the rights to use,
13  * copy, modify, merge, publish, distribute, sublicense, and/or
14  * sell copies of the Software, and to permit persons to whom the
15  * Software is furnished to do so, subject to the following
16  * conditions:
17  *
18  * The above copyright notice and this permission notice shall be
19  * included in all copies or substantial portions of the Software.
20  *
21  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
22  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
23  * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
24  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
25  * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
26  * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
27  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
28  * OTHER DEALINGS IN THE SOFTWARE.
29  *------------------------------------------------------------------
30  */
31 
32 #include "safeclib_private.h"
33 #include "safe_str_constraint.h"
34 #include "safe_str_lib.h"
35 
36 
64 rsize_t
65 strnterminate_s (char *dest, rsize_t dmax)
66 {
67  rsize_t count;
68 
69  if (dest == NULL) {
70  return (0);
71  }
72 
73  if (dmax == 0) {
74  invoke_safe_str_constraint_handler("strnterminate_s: dmax is 0",
75  NULL, ESZEROL);
76  return (0);
77  }
78 
79  if (dmax > RSIZE_MAX_STR) {
80  invoke_safe_str_constraint_handler("strnterminate_s: dmax exceeds max",
81  NULL, ESLEMAX);
82  return (0);
83  }
84 
85  count = 0;
86  while (dmax > 1) {
87  if (*dest) {
88  count++;
89  dmax--;
90  dest++;
91  } else {
92  break;
93  }
94  }
95  *dest = '\0';
96 
97  return (count);
98 }
rsize_t strnterminate_s(char *dest, rsize_t dmax)
The strnterminate_s function will terminate the string if a null is not encountered before dmax chara...
void invoke_safe_str_constraint_handler(const char *msg, void *ptr, errno_t error)
Invokes the currently set constraint handler or the default.