ultrix man page for setgroups

setgroups(2)							System Calls Manual						      setgroups(2)

Name
       setgroups - set group access list

Syntax
       #include <sys/param.h>

       setgroups(ngroups, gidset)
       int ngroups, *gidset;

Description
       The system call sets the group access list of the current user process according to the array, gidset.  The ngroups parameter indicates the
       number of entries in the array and must be no more than NGROUPS, as defined in

       Only the superuser can set new groups.

Return Values
       A 0 value is returned on success, -1 on an error, with the error code stored in errno.

Diagnostics
       The call fails if:

       [EPERM]	      The caller is not the superuser.

       [EFAULT]       The address specified for gidset is outside the process address space.

See Also
       getgroups(2), initgroups(3x)

																      setgroups(2)