解决方法
视窗
例：
char user_name[UNLEN+1];
DWORD user_name_size = sizeof(user_name);
if (GetUserName(user_name,&user_name_size))
cout << "Your user name is: " << user_name << endl;
else
/* Handle error */
Linux的
看看getpwuid：
The getpwuid() function shall search
the user database for an entry with a
matching uid.The getpwuid() function shall return a
pointer to a struct passwd
struct passwd将包含char * pw_name.
