githubmirror/libpcap

missing/win_snprintf.c

43 строки1 KB

Guy Harris

Use asprintf(), and provide a version for systems that lack it.

15 фев 2019, 00:36

15 фев 2019, 00:3635dc82d

#include <stdio.h>
#include <stdarg.h>

#include "portability.h"

int
pcap_vsnprintf(char *str, size_t str_size, const char *format, va_list args)
{
	int ret;

	ret = _vsnprintf_s(str, str_size, _TRUNCATE, format, args);

	/*
	 * XXX - _vsnprintf() and _snprintf() do *not* guarantee
	 * that str is null-terminated, but C99's vsnprintf()
	 * and snprintf() do, and we want to offer C99 behavior,
	 * so forcibly null-terminate the string.
	 *
	 * We don't, however, offer C99 behavior for the return
	 * value; _vsnprintf_s() returns -1, not the number of
	 * characters that would have been put into the buffer
	 * had it been large enough, if the string is truncated.
	 * The only way to get that value is to use _vscprintf();
	 * getting that count isn't worth the re-formatting.
	 *
	 * XXX - does _vsnprintf_s() return -1 on a formatting
	 * error?
	 */
	str[str_size - 1] = '\0';
	return (ret);
}

int
pcap_snprintf(char *str, size_t str_size, const char *format, ...)
{
	va_list args;
	int ret;

	va_start(args, format);
	ret = pcap_vsnprintf(str, str_size, format, args);
	va_end(args);
	return (ret);
}