6 * real user ID, real group ID, effective user ID, effective group ID
7 * supplementary group IDs
10 * controlling terminal
11 * set-user-ID flag and set-group-ID flag
12 * current working directory
14 * file mode creation mask
15 * signal mask and dispositions
16 * the close-on-exec flag for any open file descritors
18 * attached shared memory segments
21 A new exec()ed program inherits:
23 * process ID and parent process ID
24 * real user ID and real group ID
25 * supplementary group IDs
28 * controlling terminal
29 * time left until alarm clock
30 * current working directory
32 * file mode creation mask