SlipKnot information for Freenet and BBS sysops

SlipKnot can be used in a restricted (menu-based) environment!

If you are a Freenet sysop or administrator, and are interested in details not covered below, please contact us

Current Version Numbers as of Mar. 4, 1996:

• SlipKnot 1.50: slnot150.zip
• The SlipKnot restricted shell: 1.20 snshell.c Note: check at the top of your copy of snshell.c for the version number and if you are using version 1.0, then PLEASE UPGRADE! Another way of checking the version number is to execute the special version command while SNSHELL is running. The command is: "__snshell__" (without the quotes, and that's two underscores in front and two behind).

Contents:

• Quick Summary
• What is SlipKnot?
• SlipKnot for Freenets
• SlipKnot for BBSs
• SlipKnot FTP sites
• How does SlipKnot work?
• How to contact us

• Return to SlipKnot Home Page

Quick Summary

• SlipKnot is a PC-Windows-based graphical WWW browser, as well as a Terminal program.
• It does NOT require SLIP or PPP or TCP/IP
• It DOES require connecting to a UNIX shell or shell-like account
• We provide a free and secure "restricted shell" UNIX program for freenets that are menu-based so freenet subscribers can browse the Web using SlipKnot.

Conclusion: If you run a UNIX-based Freenet system, SlipKnot will allow your subscribers to surf the Web graphically (like Netscape or Mosaic). You DO NOT need to offer SLIP services, or change your menus (except adding one more menu item) or give up any security.

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What is SlipKnot?

MicroMind has just released version 1.50 of SlipKnot which allows the program to run with UNIX-based Freenets and certain BBS configurations. Prior to version 1.13, users of SlipKnot needed to have unrestricted UNIX shell accounts.

MicroMind now makes available the simple tools to allow UNIX-based Freenet and BBS subscribers to use SlipKnot, even on menu-based systems. The only requirement is that there must be a UNIX-based machine with Internet connectivity (BBS operators, please skip to: SlipKnot for BBS

• Published as shareware
• Registration fee to users: $29.95
• 10% of registration fees are donated to charity
• technical support available through email (we have one of the best reputations for technical support in the shareware industry)
• SlipKnot has a built-in feature for upgrading itself when new versions come out

SlipKnot is the winner of the Ziff-Davis/PC Magazine Award: Best Shareware Communications Program of 1995.

For (much) more SlipKnot general information see our SlipKnot Home Page

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SlipKnot for Freenets

If you have a UNIX-based Freenet, and allow your subscribers to access their own shell accounts, then SlipKnot will work immediately! In other words, if your subscribers can:

• get to a shell prompt
• have write-access to their directories
• execute the "lynx" program from the command line
• can download files using X or Y or Zmodem or Kermit

Solution: We provide you with a "restricted shell" program that you can install on your UNIX system to be executed by a new menu item in one of your menu screens. When that menu item is selected, it will run this shell program (called: snshell) and provide a command-line for the user. If the subscriber is using SlipKnot at this point, then she can just switch from SlipKnot's Terminal screen into the SlipKnot Web browser screen, and be off browsing.

What you need to do to install SnShell (as a freenet sysop):

1. Retrieve and compile the SlipKnot restricted shell program (Jump to SnShell information).
2. Test the shell program to ensure that it is secure for your installation (change configurations, check source code, etc.).
3. Create a menu item called, say, "World Wide Web using SlipKnot"
4. Make sure that the menu item leads to a further menu providing documentation on getting and installing SlipKnot. For instance, this menu item can lead to a submenu that looks like:
   • What is SlipKnot?
   • Getting and installing SlipKnot
   • Go to SlipKnot Shell now
5. Execute the snshell program when the user presses the "Go to SlipKnot Shell now" menu item.

Additional help for your users in getting and installing SlipKnot:

• You can carry the SlipKnot distribution file ready-to-download (jump to FTP sites)
• You can provide a SlipKnot settings file that contains most of the settings that SlipKnot users need to call your freenet (telephone number, etc.). This file is very easy to create and distribute (contact us for tips).

What a user needs to do to run SlipKnot

• Retrieve and install SlipKnot (possibly from a copy on your system).
• Ensure that the communications and other settings are correct for your freenet.
• Then for each session:
  1. Use SlipKnot as the communications Terminal to call the freenet
  2. Do all normal freenet work (mail, news, etc.) through SlipKnot Terminal screen.
  3. Navigate the menus to the SlipKnot menu item, and activate it to run the freenet's SlipKnot shell.
  4. Locally, press SlipKnot's World Wide Web button, and start surfing the Web.
  5. To leave the Web, press the SlipKnot Web Exit menu item, returning to SlipKnot Terminal and seeing the freenet's shell prompt.
  6. Type "exit" to the freenet, which will terminate the freenet's SlipKnot shell, and return to the normal menus.
  7. Eventually log off.

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What the snshell program does:

• creates a unique temporary directory for the user
• provides a prompt
• allows access only to those UNIX programs you specify in the configuration file
• removes the temporary directory when the user exits the program (by typing "exit")

snshell security

• most importantly: the program is available in source code
• will execute only those programs you specify
• will not allow "out of directory" command-line arguments (unless you allow it), e.g. "cp /etc/foo bar" is NOT allowed because one of the arguments contains the "/" character

snshell features

• single source code file, containing all usage documentation, ready- to-compile
• all configurations through a small "snshell.cfg" text file (sample config file inside the source code)
• configuration allows:
  • startup commands before user gains control (for copying files into her unique session directory, providing a signon message, etc.)
  • which UNIX commands are allowed
  • what is the "help" command for the user, and what should be printed on the screen when the user executes the help command.
  • what is the prompt
  • what is the exit command, which will terminate snshell and remove the session subdirectory

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SlipKnot for BBS sysops

For small to mid-sized BBS's, you can make an arrangement with a local UNIX-based Internet Service Provider, purchasing a single login account that can then be used through that "door" by multiple BBS subscribers. The ISP can charge somewhat more because it knows that multiple people may be using the same login ID.

With this mechanism, the BBS need not provide any direct World Wide Web service at all, because all of it would be handled by the UNIX-based ISP (which would do the document retrievals) and SlipKnot (which would display the pages and allow the navigation). The number of users that can comfortably use such a link is determined by the capacity of the BBS/UNIX communications line (and experience).

To discuss other possibilties based on your own configuration please contact us. Return to Top

FTP sites for SlipKnot and SnShell

Site/Directory/Filename

ftp.netcom.com/pub/pb/pbrooks/slipknot/slnot150.zip

interport.net/pub/pbrooks/slipknot/slnot150.zip

The SlipKnot "restricted" shell program (snshell):

Site/Directory/Filename

interport.net/pub/pbrooks/slipknot/snshell.c

or

ftp.netcom.com/pub/pb/pbrooks/slipknot/snshell.c

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How does SlipKnot work?

The Terminal is what you see when you first execute SlipKnot. It provides you with an ordinary terminal session into your service provider's UNIX system.

The WEB renderer (SlipKnot WEB) is a different program that is launched by the Terminal when you want to browse the World Wide Web. It paints and prints the documents, manages folders, keeps the retrieval job queues, etc.

Here's what happens when you request a document to be retrieved, either by pressing on an underlined link or typing in the name explicitly:

1. The WEB renderer sends your request to the Terminal (which is still active but invisible).
2. The Terminal sends the request to your service provider's UNIX system. In effect, it executes a standard UNIX command to retrieve the document or file from the remote internet computer.
3. The Terminal checks the status of this UNIX request periodically, and if it fails for any reason, it tries again.
4. When the file has been retrieved from the remote machine, it is placed by your UNIX system inside your personal directory on your UNIX system.
5. The Terminal then starts downloading that file to your PC.
6. When Terminal is finished, it sends a message to the WEB renderer indicating that the requested file is now available on your PC.
7. The WEB renderer scans the file, looking for references to any pictures that must be included in the document when it is displayed (the pictures are inside separate files on the remote computer).
8. If the WEB finds that there are pictures to be retrieved, it sends these requests to the Terminal, which retrieves them one by one.
9. When all of the necessary files have come in, the WEB renderer converts the images, and then "plots" the document (does the layout according to the typefaces you've specified in your Configure options). Then the document appears.

The separation of these two functions (communications by the Terminal, display by the WEB renderer) allows retrieval to be done in the background, while you are scrolling and reading documents in the foreground.

Design note: SlipKnot was specifically designed for modem users. Unlike other World Wide Web browsers, SlipKnot understands that its users will have to wait a while for each document to be retrieved from the internet. Therefore, we included many features to allow multiple documents to be seen, stored, and printed to prevent you from having to retrieve documents unnecessarily.

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Contacting us

Other SlipKnot installations

• Youngstown Freenet
• Akron Regional Freenet
• others pending...

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Return to SlipKnot Home Page