getgroups(2)              SYSTEM CALLS               getgroups(2)



NAME
     getgroups, setgroups - get or set supplementary group access
     list IDs

SYNOPSIS
     #include <unistd.h>

     int getgroups(int gidsetsize, gidt *grouplist)

     int setgroups(int ngroups, const gidt *grouplist)

DESCRIPTION
     getgroups gets the current supplemental group access list of
     the  calling  process  and stores the result in the array of
     group IDs specified by grouplist.  This array has gidsetsize
     entries and must be large enough to contain the entire list.
     This list cannot be greater than {NGOUPSMAX}.   If  gidset-
     size equals 0, getgroups will return the number of groups to
     which the calling  process  belongs  without  modifying  the
     array pointed to by grouplist.

     setgroups sets the supplementary group access  list  of  the
     calling  process  from  the  array of group IDs specified by
     grouplist.  The number of entries is  specified  by  ngroups
     and  can  not  be greater than {NGROUPSMAX}.  This function
     may be invoked only by the super-user.

     getgroups will fail if:

     EINVAL         The value of gidsetsize is non-zero and  less
                    than  the  number  of supplementary group IDs
                    set for the calling process.

     setgroups will fail if:

     EINVAL         The  value  of  ngroups   is   greater   than
                    {NGROUPSMAX}.

     EPERM          The effective user ID is not super-user.

     Either call will fail if:

     EFAULT         A referenced part of the array pointed to  by
                    grouplist is outside of the allocated address
                    space of the process.

SEE ALSO
     chown(2), getuid(2), setuid(2), initgroups(3C).
     groups(1) in the User's Reference Manual.

DIAGNOSTICS
     Upon successful completion, getgroups returns the number  of



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getgroups(2)              SYSTEM CALLS               getgroups(2)



     supplementary group IDs set for the calling process and set-
     groups returns the value 0.  Otherwise, a  value  of  -1  is
     returned and errno is set to indicate the error.




















































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