/* get file association function from FA file based on extension */
_fileafunc(dext = "", dfile = "")
{
        dfunc = "";

        if (strlen(dext) > 0)
        {
                if (strlen(dfile) == 0)
                {
                        dfile = _fileafname();
                }

                /* stringify file */
                dstr  = strfile(dfile, 0, 1);

                /* locate extension */
                dfunc = strfind(dext, dstr);

                /* comma, space and newlines are separators */
                dfunc = strget(2, dfunc, strescape(", \n"));
        }

        return(dfunc);
}