29.Oct.97

			SWTCH V1.2	(Switch)
		       ~~~~~~~~~~~~~~~~~~~~~~~~~~
	I would like to hear, if you like this program, or have any comments
	or ideas about it. (You can reach me per EMail, or Fido-Netmail.)

	My Fido-Net address is:
		Tobias Winkler@2:2411/901.38  (Bummi-Box,Frankfurt/Oder)

	By Internet-EMail I can be reached at this address:
		Tobias_Winkler@p38.f901.n2411.z2.sesom.de


 Switch is a small utility making it possible to run more than one external
 program from a shell, even if the shell only supports one.

 To make it easier, here an example:
  Think about a filemanager, which has an external viewer named VIEW.EXE,
  which is started with key F3. Unfortunately this filemanager has no support
  for different viewers.
  Here is the point, where Switch helps.
  Simply copy SWTCH.EXE over VIEW.EXE and make your SWITCH.INI-file.
  Switch gives you the chance to call different programs, depending on the
  key pressed after the start-key (start-key is F3 in the example).

  So MYVIEW.COM could be called, if F4 is pressed after F3. XYZVIEW.EXE if
  F3 is pressed twice. And another viewer, maybe the original VIEW.EXE, can
  be called, if only F3 and no additional key is pressed, after a certain
  time (1/18 second for default).

  Last but not least a program can be called, if a the start-key is still
  pressed after timeout.

  (So it is possible to call 3 different viewers with only 1 start-key.
   Something for lazy people like me ;-)

 Switch uses an ini-file called SWITCH.INI (must be placed to the same
 directory as SWTCH.EXE).

 Each line in this file defines a key-code (decimal) and a program for this
 key. Keycode and name of the program must be devided by a comma ",".
 The name of the program must be complete. This means, that the complete path
 of the program and the extension (".EXE" or ".COM") must be included.
 Batchfiles can't be called directly. For them, you have to call your
 COMMAND.COM with /C before the name of the batchfile. (see below for example)

 (Keycodes (also called Scancodes) are the values generated by the keyboard
  and sent to IO-port 60h (hexadecimal), when a key is pressed.

  For example the function-keys F1 to F10 occupy the scancodes 59 to 68.


  If you have no source for these codes, try this turbo-pascal program:
	{--------------------CUT--BEGIN------------------------}
	begin
	 repeat
	  mem[$40:$1A]:=mem[$40:$1C];		{- clear keybuffer }
	  while mem[$40:$1A]=mem[$40:$1C] do;	{- wait for a keypress }
	  writeln('Scancode: ',mem[$40:mem[$40:$1A]+1]); {- write scancode }
	 until mem[$40:mem[$40:$1A]]=27;	 {- Exit if ESC pressed}
	end.
	{--------------------CUT---END-------------------------}
 )


    Example for SWITCH.INI:

	>	9
	>	p,1
	>	m,/MEM,1
	>	62,C:\UTILS\MYVIEW.EXE
	>	28,C:\COMMAND.COM /C VIEWSOME.BAT
	>	61,F:\XYZ\XYZVIEW.EXE
	>	255,C:\UTILS\ANSIVIEW.COM /X
	>	0,C:\SHELL\VIEW.EXE

 (Any resemblance of the names to living or dead programs is purely
  coincidental (and absolutely wanted). ;->)

 The optional value in the first line is the time in 1/18 seconds, while
 Switch shall wait for a second keypress. (In the example it would be a half
 second. (9 * 1/18=0.5))

 [P,1[,2...]	- this optional parameters tells Switch, which commandline-
		  parameters shall be given to the viewers
 Hmm, I'll better give an example:

	>	p,1,4

 will force Switch to give the 1st and the 4th parameter to the called program.


 [m,<PARAM>,<OFFSET>]	- this is used for support of programs (like NC 5.0)
			  which give only the (absolute) memory-address of the
			  filename's position in RAM.
			  <PARAM> is a string which leads the address as a
			  parameter.
			  <OFFSET> is a value which will be added to the given
			  memory-address, to get the position of the (zero-
			  terminated) filename-string.
 Simply said: use

	>	m,/MEM,1

 for using Switch with NC 5.0.


 The keycodes 0 and 255 are special ones (because the keyboard won't generate
 them.)
 0 is assumed, if no second key is pressed until timeout.
 255, if no additional key is pressed, and the start-key is still pressed.

 If a key was pressed, but is not fitting to a scancode in the ini-file, the
 command from the LAST line of SWITCH.INI will be called. (C:\SHELL\VIEW.EXE in
 the example.)

 As parameters (commandline) for the called program is everything taken, what
 is behind the actual programname (divided by a space), plus the parameters
 given to Switch (or at least the parameters allowed with "P,...").

 (You can give some special-characters in front of the program-names, for
  some extra-functions:
   ,  - force Switch to give the program none of the parameters
   ;  - wait for a keypress after the program is terminated
   *  - clear screen after the program is terminated

 e.g:	0,,;*c:\dos\mem.exe
 )

 If the program couldn't be called for any reason, Switch will beep.
 I did not include any messages or helptexts in Switch, to make it as small
 as possible (as possible with TP 7.0 ;-)).


 (The reason why, the actual executable file is called SWTCH.EXE, is that
  I use Novell DOS 7, where SWITCH is already an internal command.

  (You can imagine what I tried to debug my program, which was not doing
  anything, until I remembered Novell's SWITCH-command... :-])

That's all for now...
Bye
	TW.