PECULIARITIES OF BATCH FILE PROCESSING WITH PTS-DOS SHELL

     Such processing has some particular features as compared to standard
procedure.

     First and most important among them is that the Shell launches a
special process for batch file executing and terminates it when batch file
processing is interrupted for some reason. This has some consequents:

1. All batch files accessed for processing from the given one, upon their
   termination return the control back to the given batch file.
2. Re-directing "console" device command is a local one for the batch
   file, i.e. after the batch file is processed the state of standard
   I/O devices is restored.
3. There is a possibility to use redirection of input-output flows for
   the batch file as a whole.

     Another particularity is the use of reserved names while processing DOS
environment variables. If the following "names" are used as environment
variables names after % symbols:

   DIR, NAME, DIRNAME, EXT;

then the line processing proceeds as follows. The parameter immediately
following such a "name" is considered to be the full variable name. A part
of the this variable name is to be used in the command, while the rest is to
be omitted. The remaining parts of variable names are correspondingly:  file
directory, file name only (without extention), file directory and name
(extention is omitted), filename extention only.

     The other special feature is the access to the canonical full name of a
batch file under processing. Reference pseudoparameter "%$" is used for this
purpose.

Example:

Suppose there is TEST.BAT file on drive C: in \DIRBAT\ directory.

 executing the following
 lines of the given batch:               will cause the output:

 @echo %DIR% %$                           C:\DIRBAT
 @echo %NAME% %$                          TEST
 @echo %DIRNAME% %$                       C:\DIRBAT\TEST
 @echo %EXT% %$                           BAT
 @echo %$                                 C:\DIRBAT\TEST.BAT