setgroups() -- System Call (libc)

Set the supplemental group-access list
#include <unistd.h>
int setgroups(ngroups, grouplist)
int ngroups; const gid_t *grouplist;

The  ``supplemental group-access  list'' is the  list of  group identifiers
that  are  used  in   addition  to  the  effective  group  identifier  when
determining the level of access that  a process has to a file.  setgroups()
fills the  calling process's supplemental group-access  list with the group
identifiers  in the  array to  which grouplist  points.  ngroups  gives the
number of identifiers in the array, and cannot exceed NGROUPS_MAX.

If all goes well, setgroups() returns zero.  It fails and returns -1 if any
of the following occur:

-> The  value  of  ngroups exceeds  NGROUPS_MAX.  setgroups  sets errno  to
   EINVAL.

-> The  effective  user identifier  is  not that  of  the super-user  root.
   setgroups() sets errno to EPERM.

-> grouplist  contains  an  illegal  address.   setgroups() sets  errno  to
   EFAULT.

See Also

getgroups(),
initgroups(),
libc,
limits.h,
unistd.h

Notes

This function may be invoked only by the superuser root.

© 2012 by Stephen A. Ness