TESTCODE: NULL is safe as a argument of printf("%s")

printf-null.cpp

#include <stdio.h>
#include <stdlib.h>
int main()
{
	char buf[200];
	puts("*** test printf NULL");
	printf(        "printf   :%s,%S,%ws\n", NULL, NULL, NULL);
#ifdef _MSC_VER
	sprintf_s(buf, "sprintf_s:%s,%S,%ws\n", NULL, NULL, NULL); puts(buf);
#endif
	return 0;
}
/*
RESULT: VC9(vs2008) on Windows7
*** test printf NULL
printf   :(null),(null),(null)
sprintf_s:(null),(null),(null)

RESULT: gcc4.8.3 on cygwin
*** test printf NULL
printf   :(null),(null),ws
*/