4.3BSD - /usr/man/cat2/getgroups.0

GETGROUPS(2)                                                      GETGROUPS(2)


NAME
       getgroups - get group access list

SYNOPSIS
       #include <sys/param.h>

       ngroups = getgroups(gidsetlen, gidset)
       int ngroups, gidsetlen, *gidset;

DESCRIPTION
       Getgroups  gets  the  current group access list of the user process and
       stores it in the array gidset.  The parameter gidsetlen  indicates  the
       number  of entries that may be placed in gidset.  Getgroups returns the
       actual number of groups returned in gidset.  No more than  NGROUPS,  as
       defined in <sys/param.h>, will ever be returned.

RETURN VALUE
       A  successful  call  returns  the number of groups in the group set.  A
       value of -1 indicates that an error occurred, and  the  error  code  is
       stored in the global variable errno.

ERRORS
       The possible errors for getgroup are:

       [EINVAL]       The  argument  gidsetlen  is  smaller than the number of
                      groups in the group set.

       [EFAULT]       The argument gidset specifies an invalid address.

SEE ALSO
       setgroups(2), initgroups(3X)

BUGS
       The gidset array should be of type gid_t, but remains integer for  com‐
       patibility with earlier systems.


4.2 Berkeley Distribution        May 13, 1986                     GETGROUPS(2)