2.4 SVM Command-line Parameters

When executed without any command-line parameter, SVM prints out the following messages to the console:

=========================================================
|  Python Implementation of Statechart Virtual Machine  |
|                          Version 0.3                  |
|              Presented by Thomas Feng, Nov. 2003      |
=========================================================

Usage: svm [options...] <.des|.snp file> [parameters...]
       options:
           -c: force curses interface (Linux)
           -t: force textual interface
           -i <file>: include a file (to the head)
           -I <file>: include a file (to the tail)
       parameters:
           "name=value"

The meaning of the accepted command-line parameters is explained below:

• The -c parameter enforces the curses interface (if the simulated model does not provide a model-specific interface). Curses is a colorful textual library for Unix-based systems. It is not supported in Windows.

  For example, the users may run the HelloWorld example with the following command:

  svm -c HelloWorld.des
  

• The -t parameter enforces the textual interface (if the simulated model does not provide a model-specific interface). This interface is suitable for most systems and machines, even if the Tk library is not supported or no graphical device is available. It is also more efficient than the default graphical interface.

  For example, the users may run the HelloWorld example with the following command:

  svm -t HelloWorld.des
  

• The -i parameter literally inserts a text file to the head of the model description. This option is very useful when the designer designs a group of models and wants them to share a common part of description (for example, the interactor or the initializer). In that case, the designer writes the common part in a separate text file, and inserts the file to the model descriptions at the time of simulation.

  Multiple text files can be inserted with multiple -i parameters on the command-line. For example, a1.des contains the following content:

  STATECHART:
  

  a2.des contains the following content:

      A [DS]
  

  And a3.des contains the following content:

      B
  

  To combine those descriptions and simulate the model in SVM, the user should execute the following command:

  svm -i a1.des -i a2.des a3.des
  

  (Note: there must be exactly one main file on the command-line which is not preceded by the -i parameter, in this case, a3.des.) The resulting model is equivalent to the following:

  STATECHART:
      A [DS]
      B
  

  (It is a model with two states but without transition.)

• The -I parameter is similar to -i, except that the file is appended to the end of the model description. As a result, the model discussed above can also be simulated with the following command:

  svm -I a2.des -I a3.des a1.des
  

• The main file follows all the -i parameters and -I parameters (if any). After the main file, the user may specify one or more macro redefinitions. Those macro redefinitions override the macros defined in the model, but they do not affect the submodels that are imported into the main model (whose description is the combination of all the text files that appear in the command-line).

  For example, DUMP is a predefined macro (discussed later) used in the HelloWorld example. The example prints ``Hello World!'' when event e is received. To override this macro on the SVM command-line, the user may execute the following command:

  svm -t HelloWorld.des 'DUMP(msg)=print "example:", [msg]'
  

  When event e is received, instead of printing ``Hello World!'' the model prints ``example: Hello World!''