Web-based terminal emulation

[Jeff_Traigle]

I know about WRQ's Reflection for the Web that does vt emulation. Was wondering what other companies have similar products that provide encrypted connections and passthrough printing.

[Steven E. Protter · Accepted solution]

I believe hummingbird has a competitive product.

HP's secure webconsole may meet the criteria though I've never tried to print off mine.

SEP

[Bill Hassell]

As far as I know, WRQ's web tool is unique in providing SSH from the client to server. Also, WRQ's product actually downloads Java code to each client which is controlled by the web server. This means that the local user can be completely controlled by the web server so changing from telnet to ssh or vt to hp emulation can be accomplished with a simple change at the web server. Each Java download has a version number that is verified by the server and if a newer version exists, it is replaced automatically. This is a powerful tool to control the changes that an end user is allowed to make to the terminal window. It saves endless calls to support when a typical terminal emulator is misconfigured by users that want to experiment.

[Bill Hassell]

Passthrough printing can be tested with:

echo "$(tput mc5)\c"
cat some_file
echo "$(tput mc4)\c"

NOTE: many terminal emulators have their own ideas about the acceptable escape sequences. A 'normal' terminal emulator can be identified with ttytype -s and once TERM has been set. the above tput construct will work just fine. The problem is that an emulator may answer ID queries as a vt100 (which does NOT support passthrough printing) yet sending the codes:

echo "\033[5i"
echo passthrough printing is now in force
echo "\033[4i"

may work OK (DEC VT series or ANSI emulation). This is a problem that is often fixed by hardcoding TERM= in /etc/profile and then messes up other terminal emulators by sending the wrong codes. tput mc5 produces nothing when TERM=vt100 as it should. untic vt100 and untic vt200 will show the differences.

[Steven E. Protter]

Actually Bill & all, Hummingbird just started offering an ssh package as an add in to their product.

SEP

[Mark Greene_1]

Putty is a freeware Windows-based ssh client:

http://www.chiark.greenend.org.uk/~sgtatham/putty/

[Jeff_Traigle]

Thanks for the input.

I evaluated WRQ's product a few years ago (before the encryption features were added) and really liked the ease of installation, configuration, and control provided.

Hummingbird has some good products and I'll look into theirs. It took them a few years to get their web-based X emulator to a point where I was willing to implement it at my previous job... and it still had a few bugs, but compared to the price of licensing the "fat" client for every PC in the facility, it was worth the minor annoyances of the bugs. They were at least working with me to fix the problems.

The HP secure web console won't work for multiple users accessing the system at once. I think there are terminal type problems with the application running on the vt100 console anyway that wouldn't make this feasible.

Putty would be fine for direct access, but the intended environment requires more control than a Windows-based client can provide.

How does the passthrough printing work on the Windows client side? Does it go straight to the default printer or can it be forced to open the printer selection window so the user can select a destination?

[Bill Hassell]

Passthrough printing is defined by the client program. For WRQ products, it is the current printer for the user. Another client (not web based) SecureNetTerm has no defaults and the printer must be selected. From then on, that will be the passthrough printer. Passthrough printing is VERY basic--it simply tells the emulator to redirect whatever follows the escape sequence to the selected printer. The man page for terminfo (curses) will detail the printer capabilities.There may be emulator-specific codes to do a little bit more but nothing that would be portable.

[Jeff_Traigle]

I had a feeling that would be the case. We'd have to implement some kind of secure printing solution through firewalls then.