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This program uses one variable to hold eight privilege flags. The programmer wants to set the administration (P_ADMIN) and backup master (P_BACKUP) privileges for the given user and then verify that the bits were properly set. What is really happening?
1 /************************************************
2 * print_privs -- Print some of the privilege *
3 * flags. *
4 ************************************************/
5 #include <iostream>
6
7 #define CI const int
8 CI P_USER = (1 << 1); // Normal user privileges
9 CI P_REBOOT = (1 << 2); // Can reboot systems
10 CI P_KILL = (1 << 3); // Can kill any process
11 CI P_TAPE = (1 << 4); // Can use tape devices
12 CI P_RAW = (1 << 5); // Can do raw io
13 CI P_DRIVER = (1 << 6); // Can load drivers
14 CI P_ADMIN = (1 << 7); // Can do administration
15 CI P_BACKUP = (1 << 8); // Can do backups
16
17 int main()
18 {
19 // The privileges
20 unsigned char privs = 0;
21
22 // Set some privs
23 privs |= P_ADMIN;
24 privs |= P_BACKUP;
25
26 std::cout << "Privileges: ";
27
28 if ((privs & P_ADMIN) != 0)
29 std::cout << "Administration ";
30
31 if ((privs & P_BACKUP) != 0)
32 std::cout << "Backup ";
33
34 std::cout << std::endl;
35 return (0);
36 }
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