util.py 文件源码

def initgroups(uid, primaryGid):
        """Initializes the group access list.

        This is done by reading the group database /etc/group and using all
        groups of which C{uid} is a member.  The additional group
        C{primaryGid} is also added to the list.

        If the given user is a member of more than C{NGROUPS}, arbitrary
        groups will be silently discarded to bring the number below that
        limit.
        """       
        try:
            # Try to get the maximum number of groups
            max_groups = os.sysconf("SC_NGROUPS_MAX")
        except:
            # No predefined limit
            max_groups = 0

        username = pwd.getpwuid(uid)[0]
        l = []
        if primaryGid is not None:
            l.append(primaryGid)
        for groupname, password, gid, userlist in grp.getgrall():
            if username in userlist:
                l.append(gid)
                if len(l) == max_groups:
                    break # No more groups, ignore any more
        try:
            _setgroups_until_success(l)
        except OSError, e:
            # We might be able to remove this code now that we
            # don't try to setgid/setuid even when not asked to.
            if e.errno == errno.EPERM:
                for g in getgroups():
                    if g not in l:
                        raise
            else:
                raise