PHP Telnet - 发送BackSpace

Question

I'm using php4 to connect to an old router.

Once the connection is made and I've logged in I send a series of commands..

As I know the output of the router I can answer the questions it is asking directly, so I send :

fputs($fp,"Upgrade"); // run upgrade command
fputs($fp,"y"); // Send y for Yes 
fputs($fp,""); // send return

The next line I need to send is backspace 5 times. I've tried

fputs($fp,"\^h");
fputs($fp,"\x08");
fputs($fp,"\BS");

they all send but nothing is back spacing.. how do I send 5 backspaces to delete the current entry and then I can send my new entry ?

Thanks

Answer 1

Have you tried sending

chr(8)

directly (no String operations etc.)?

Do you know whether the router uses standard telnet protocol or is it a proprietary (extended) protocol used by some special router management application?

@Comment: I don't believe ASCII code 7 will work as it's BEL, isn't it? See http://tools.ietf.org/html/rfc137, page 8