1SETGID(2) Linux Programmer's Manual SETGID(2)
2
3
4
6 setgid - set group identity
7
9 #include <sys/types.h>
10 #include <unistd.h>
11
12 int setgid(gid_t gid);
13
15 setgid() sets the effective group ID of the current process. If the
16 caller is the superuser, the real GID and saved set-group-ID are also
17 set.
18
19 Under Linux, setgid() is implemented like the POSIX version with the
20 _POSIX_SAVED_IDS feature. This allows a set-group-ID program that is
21 not set-user-ID-root to drop all of its group privileges, do some un-
22 privileged work, and then re-engage the original effective group ID in
23 a secure manner.
24
26 On success, zero is returned. On error, -1 is returned, and errno is
27 set appropriately.
28
30 EPERM The calling process is not privileged (does not have the
31 CAP_SETGID capability), and gid does not match the effective
32 group ID or saved set-group-ID of the calling process.
33
35 SVr4, POSIX.1-2001.
36
38 getgid(2), setegid(2), setregid(2), capabilities(7)
39
40
41
42Linux 2.5 2002-03-09 SETGID(2)