[ILUG] Re: Telnet

[Vincent Murphy]

= Michael Conry <mconry at pop3.ucd.ie> [20000211 1430]:
>  What is the significance/use of the TERM environment variable.

 TERM is used by libraries like termcap, terminfo and so forth to find out
what kind of terminal you're using.  most people these days are using virtual
terminals (e.g. xterm), but these are still just terminals like any other from
termcap and terminfo's perspective.

 this page has a wealth of information on terminals in general, most of which
is applicable to virtual terminals also.

 http://www.cs.utk.edu/~shuford/terminal_index.html

> If i leave
> it as linux, then I get problems telnetting into a SGI Irix sys (says
> linux unknown). If i set it to vt100, this difficulty disappears (are
> there any other implications).

 this is probably because the terminal-handling library on the irix system
doesn't have an entry in it's database for the terminal that's called `linux'.
telnet passes this environment value through to the new session on the remote
host.  thus it is the terminal-handling library (termcap or terminfo) on the
remote system that's giving the error.

 what this means is that you need to add a `linux' entry to the database,
which is more than likely a job for your sysadmin.

 the other way to get around it this is to build your own ncurses and terminfo
in your home directory on the irix system.  i did this on digital unix system
here in college and specified in the TERMINFO environment variable that i
wanted my own private terminfo used (further details on request).  the
terminfo database is pretty comprehensive, so doing this pretty much
eliminates these type of problems.

 i think the root cause is that many of these commerical unices are using
termcap, which is older than terminfo, and thus has a crappier
vendor-supplied terminal database.

>  Also, when in an xterm, i can backspace within a line in vi running
> through telnet on the SGI. In a regular terminal, this does not work. (I
> can always backspace in a locally run vi).

 at a stretch `stty erase ^?' or `stty erase ^H' might do the trick but i
don't know for sure.  if backspace works with your shell but not vi, you may
have a vi configuration problem.

>  Just curious really
> 	thanks
> mick

HTH..
-vinny
.