NAME
setregid - set real and effective group IDs
SYNOPSIS
#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.
The following sections are informative.
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>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group. In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online
at http://www.opengroup.org/unix/online.html .