win_snprintf.c revision 356341 
1#include <stdio.h>
2#include <stdarg.h>
3
4#include "portability.h"
5
6int
7pcap_vsnprintf(char *str, size_t str_size, const char *format, va_list args)
8{
9	int ret;
10
11	ret = _vsnprintf_s(str, str_size, _TRUNCATE, format, args);
12
13	/*
14	 * XXX - _vsnprintf() and _snprintf() do *not* guarantee
15	 * that str is null-terminated, but C99's vsnprintf()
16	 * and snprintf() do, and we want to offer C99 behavior,
17	 * so forcibly null-terminate the string.
18	 *
19	 * We don't, however, offer C99 behavior for the return
20	 * value; _vsnprintf_s() returns -1, not the number of
21	 * characters that would have been put into the buffer
22	 * had it been large enough, if the string is truncated.
23	 * The only way to get that value is to use _vscprintf();
24	 * getting that count isn't worth the re-formatting.
25	 *
26	 * XXX - does _vsnprintf_s() return -1 on a formatting
27	 * error?
28	 */
29	str[str_size - 1] = '\0';
30	return (ret);
31}
32
33int
34pcap_snprintf(char *str, size_t str_size, const char *format, ...)
35{
36	va_list args;
37	int ret;
38
39	va_start(args, format);
40	ret = pcap_vsnprintf(str, str_size, format, args);
41	va_end(args);
42	return (ret);
43}
44