Unknown option: "-2" Unix manual page for getgrouplist. (host=minya system=Darwin)
GETGROUPLIST(3)          BSD Library Functions Manual          GETGROUPLIST(3)

NAME
     getgrouplist -- calculate partial group access list

LIBRARY
     Standard system libraries.

SYNOPSIS
     #include <unistd.h>

     int
     getgrouplist(const char *name, int basegid, int *groups, int *ngroups);

DESCRIPTION
     The getgrouplist() function obtains information from opendirectoryd(8) to
     construct the group access list for the user specified in name.  The
     basegid is automatically included in the groups list.  Typically this
     value is given as the default group number from the user's account
     record.

     The resulting group list is returned in the array pointed to by groups.
     The caller specifies the size of the groups array in the integer pointed
     to by ngroups; the actual number of groups found is returned in ngroups.

RETURN VALUES
     The getgrouplist() function returns 0 on success.  If the size of the
     group list is too small to hold all the user's groups, getgrouplist()
     returns -1 to indicate failure.  In this case, the group array will be
     filled with as many groups as will fit.

FILES
     /etc/group  group membership list

SEE ALSO
     setgroups(2), initgroups(3), opendirectoryd(8).

HISTORY
     The getgrouplist() function first appeared in 4.4BSD.

BSD                              June 9, 1993                              BSD