#define setenv(varname, value, overwrite) _putenv_s((varname), (value))
#define unsetenv(varname) _putenv_s(varname, "")
#endif
#define setenv(varname, value, overwrite) _putenv_s((varname), (value))
#define unsetenv(varname) _putenv_s(varname, "")
#endif