GETGROUPS(2)              386BSD Programmer's Manual              GETGROUPS(2)

NAME
     getgroups - get group access list

SYNOPSIS
     #include <sys/param.h>
     #include <unistd.h>

     int
     getgroups(int gidsetlen, int *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 VALUES
     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 getgroups() 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(3)

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

HISTORY
     The getgroups function call appeared in 4.2BSD.

4.2 Berkeley Distribution       March 10, 1991                               1