1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
|
/*
* Copyright (c) 2000-2001 Sendmail, Inc. and its suppliers.
* All rights reserved.
* 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.
*
* By using this file, you agree to the terms and conditions set
* forth in the LICENSE file which can be found at the top level of
* the sendmail distribution.
*/
#include <sm/gen.h>
SM_RCSID("@(#)$Id: snprintf.c,v 1.23 2001/09/11 04:04:49 gshapiro Exp $")
#include <limits.h>
#include <sm/varargs.h>
#include <sm/io.h>
#include "local.h"
/*
** SM_SNPRINTF -- format a string to a memory location of restricted size
**
** Parameters:
** str -- memory location to place formatted string
** n -- size of buffer pointed to by str, capped to
** a maximum of INT_MAX
** fmt -- the formatting directives
** ... -- the data to satisfy the formatting
**
** Returns:
** Failure: -1
** Success: number of bytes that would have been written
** to str, not including the trailing '\0',
** up to a maximum of INT_MAX, as if there was
** no buffer size limitation. If the result >= n
** then the output was truncated.
**
** Side Effects:
** If n > 0, then between 0 and n-1 bytes of formatted output
** are written into 'str', followed by a '\0'.
*/
int
#if SM_VA_STD
sm_snprintf(char *str, size_t n, char const *fmt, ...)
#else /* SM_VA_STD */
sm_snprintf(str, n, fmt, va_alist)
char *str;
size_t n;
char *fmt;
va_dcl
#endif /* SM_VA_STD */
{
int ret;
SM_VA_LOCAL_DECL
SM_FILE_T fake;
/* While snprintf(3) specifies size_t stdio uses an int internally */
if (n > INT_MAX)
n = INT_MAX;
SM_VA_START(ap, fmt);
/* XXX put this into a static? */
fake.sm_magic = SmFileMagic;
fake.f_file = -1;
fake.f_flags = SMWR | SMSTR;
fake.f_cookie = &fake;
fake.f_bf.smb_base = fake.f_p = (unsigned char *)str;
fake.f_bf.smb_size = fake.f_w = n ? n - 1 : 0;
fake.f_timeout = SM_TIME_FOREVER;
fake.f_timeoutstate = SM_TIME_BLOCK;
fake.f_close = NULL;
fake.f_open = NULL;
fake.f_read = NULL;
fake.f_write = NULL;
fake.f_seek = NULL;
fake.f_setinfo = fake.f_getinfo = NULL;
fake.f_type = "sm_snprintf:fake";
ret = sm_io_vfprintf(&fake, SM_TIME_FOREVER, fmt, ap);
if (n > 0)
*fake.f_p = '\0';
SM_VA_END(ap);
return ret;
}
|
