def page_file(fname, start=0, pager_cmd=None):
    """Page a file, using an optional pager command and starting line.
    """

    pager_cmd = get_pager_cmd(pager_cmd)
    pager_cmd += ' ' + get_pager_start(pager_cmd,start)

    try:
        if os.environ['TERM'] in ['emacs','dumb']:
            raise EnvironmentError
        system(pager_cmd + ' ' + fname)
    except:
        try:
            if start > 0:
                start -= 1
            page(open(fname).read(),start)
        except:
            print 'Unable to show file',`fname`
Page a file, using an optional pager command and starting line.