set_client_encoding (PGconn)

    /*
     * call-seq:
     *    conn.set_client_encoding( encoding )
     *
     * Sets the client encoding to the _encoding_ String.
     */
    static VALUE
    pgconn_set_client_encoding(obj, str)
        VALUE obj, str;
    {
        Check_Type(str, T_STRING);
        if ((PQsetClientEncoding(get_pgconn(obj), StringValuePtr(str))) == -1){
            rb_raise(rb_ePGError, "invalid encoding name %s",str);
        }
        return Qnil;
    }