case CTRL('H'): case CTRL('?'):
case KCTRL('H'): case KCTRL('?'):
void ldisc_send(char *buf, int len){    /*     * Called with len=0 when the options change. We must inform     * the front end in case it needs to know.     */    if (len == 0) {	void ldisc_update(int echo, int edit);	ldisc_update(ECHOING, EDITING);    }    /*     * Either perform local editing, or just send characters.     */    if (EDITING) {	while (len--) {	    char c;	    c = *buf++;	    switch (term_quotenext ? ' ' : c) {		/*		 * ^h/^?: delete one char and output one BSB		 * ^w: delete, and output BSBs, to return to last		 * space/nonspace boundary		 * ^u: delete, and output BSBs, to return to BOL		 * ^c: Do a ^u then send a telnet IP		 * ^z: Do a ^u then send a telnet SUSP		 * ^\: Do a ^u then send a telnet ABORT		 * ^r: echo "^R\n" and redraw line		 * ^v: quote next char		 * ^d: if at BOL, end of file and close connection,		 * else send line and reset to BOL		 * ^m: send line-plus-\r\n and reset to BOL		 */	      case CTRL('H'):	      case CTRL('?'):	       /* backspace/delete */		if (term_buflen > 0) {		    if (ECHOING)			bsb(plen(term_buf[term_buflen - 1]));		    term_buflen--;		}		break;	      case CTRL('W'):	       /* delete word */		while (term_buflen > 0) {		    if (ECHOING)			bsb(plen(term_buf[term_buflen - 1]));		    term_buflen--;		    if (term_buflen > 0 &&			isspace(term_buf[term_buflen - 1]) &&			!isspace(term_buf[term_buflen]))			break;		}		break;	      case CTRL('U'):	       /* delete line */	      case CTRL('C'):	       /* Send IP */	      case CTRL('\\'):	       /* Quit */	      case CTRL('Z'):	       /* Suspend */		while (term_buflen > 0) {		    if (ECHOING)			bsb(plen(term_buf[term_buflen - 1]));		    term_buflen--;		}		back->special(TS_EL);		if (c == CTRL('C'))		    back->special(TS_IP);		if (c == CTRL('Z'))		    back->special(TS_SUSP);		if (c == CTRL('\\'))		    back->special(TS_ABORT);		break;	      case CTRL('R'):	       /* redraw line */		if (ECHOING) {		    int i;		    c_write("^R\r\n", 4);		    for (i = 0; i < term_buflen; i++)			pwrite(term_buf[i]);		}		break;	      case CTRL('V'):	       /* quote next char */		term_quotenext = TRUE;		break;	      case CTRL('D'):	       /* logout or send */		if (term_buflen == 0) {		    back->special(TS_EOF);		} else {		    back->send(term_buf, term_buflen);		    term_buflen = 0;		}		break;	      case CTRL('M'):	       /* send with newline */		if (term_buflen > 0)		    back->send(term_buf, term_buflen);		if (cfg.protocol == PROT_RAW)		    back->send("\r\n", 2);		else		    back->send("\r", 1);		if (ECHOING)		    c_write("\r\n", 2);		term_buflen = 0;		break;	      default:		       /* get to this label from ^V handler */		if (term_buflen >= term_bufsiz) {		    term_bufsiz = term_buflen + 256;		    term_buf = saferealloc(term_buf, term_bufsiz);		}		term_buf[term_buflen++] = c;		if (ECHOING)		    pwrite(c);		term_quotenext = FALSE;		break;	    }	}    } else {	if (term_buflen != 0) {	    back->send(term_buf, term_buflen);	    while (term_buflen > 0) {		bsb(plen(term_buf[term_buflen - 1]));		term_buflen--;	    }	}	if (len > 0) {	    if (ECHOING)		c_write(buf, len);	    back->send(buf, len);	}    }}