NAME

setregid - set real and effective group IDs

SYNOPSIS

[XSI] #include <unistd.h>

int setregid(gid_t rgid, gid_t egid);

DESCRIPTION

The setregid() function shall set the real and effective group IDs of the calling process.

If rgid is -1, the real group ID shall not be changed; if egid is -1, the effective group ID shall not be changed.

The real and effective group IDs may be set to different values in the same call.

Only a process with appropriate privileges can set the real group ID and the effective group ID to any valid value.

A non-privileged process can set either the real group ID to the saved set-group-ID from one of the exec family of functions, or the effective group ID to the saved set-group-ID or the real group ID.

Any supplementary group IDs of the calling process remain unchanged.

RETURN VALUE

Upon successful completion, 0 shall be returned. Otherwise, -1 shall be returned and errno set to indicate the error, and neither of the group IDs are changed.

ERRORS

The setregid() function shall fail if:

[EINVAL]

The value of the rgid or egid argument is invalid or out-of-range.

[EPERM]

The process does not have appropriate privileges and a change other than changing the real group ID to the saved set-group-ID, or changing the effective group ID to the real group ID or the saved set-group-ID, was requested.

EXAMPLES

None.

APPLICATION USAGE

If a set-group-ID process sets its effective group ID to its real group ID, it can still set its effective group ID back to the saved set-group-ID.

RATIONALE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

exec(), getegid(), geteuid(), getgid(), getuid(), setegid(), seteuid(), setgid(), setreuid(), setuid(), the Base Definitions volume of IEEE Std 1003.1-2001, <unistd.h>

CHANGE HISTORY

First released in Issue 4, Version 2.

Issue 5

Moved from X/OPEN UNIX extension to BASE.

The DESCRIPTION is updated to indicate that the saved set-group-ID can be set by any of the exec family of functions, not just execve().