When an application is launched by clicking a button in mmLaunch or from the command shell like
> tclsh oommf.tcl mmdisp
the application (here mmDisp) is not executed directly but rather
through the “bootstrap” program oommf.tcl. The bootstrap
constructs a list linking application names to commands
using the appindex.tcl files in the various application (oommf/app/)
directories, and then runs the command associated with the given
name. This is convenient for normal use, but the additional execution
layer can obfuscate the debugging process. You can obtain the
direct command from the bootstrap program itself with the +command
option
> tclsh oommf.tcl mmdisp +command
app/mmdisp/windows-x86_64/mmdispsh.exe app/mmdisp/scripts/mmdisp.tcl &
The response is the command as used inside a Tcl shell to launch the
application. You may need to make minor edits to run the application at
your shell command prompt. For example, the trailing ampersand runs the
program in the background, which is not what one usually wants when
debugging, so you would omit this. On Windows you may want to change
the forward slash path separators to backslashes. Another
Windows-specific modification involves the first component of this
command, app/mmdisp/windows-x86_64/mmdispsh.exe. This is an
executable containing an embedded Tcl interpreter that processes the
Tcl script specified as the second command component. If you examine
the app/mmdisp/windows-x86_64/ directory you’ll find two
executables, mmdispsh.exe and condispsh.exe. On Unix and
macOS these two programs are the same, but on Windows the first is
linked as a native Windows application and the second as a console
application. The importance of this is that only the second provides the
usual C++ standard channels stdin, stdout, and
stderr. In case of abnormal operation programs will sometimes write
error messages to stdout or stderr, which will be lost if the
program is not running as a console application. The upshot is that for
debugging purposes you would probably want to run mmDisp (for
example) from a Windows command console as
> app\mmdisp\windows-x86_64\condispsh.exe app/mmdisp/scripts/mmdisp.tcl
It is worth noting that on the bootstrap command line, arguments starting with ‘+’ (for example, “+command”) are options to oommf.tcl itself. Run “tclsh oommf.tcl +h” to see the bootstrap help message. Options to the OOMMF application follow the application name and start with ‘-’. For example, to see the help message for a particular application, run “tclsh oommf.tcl <appName> -h”.