started by [Theo Verelst]

[Pcom] is a small package intended to offer one to one chat-like contact and back and forth file transfer with straightforward socket connections and adjustable port number, which also allows remote (tcl/tk) command execution.

The tcl [exec] command executes an external program on the same machine under the conditions of the current operating system. Under windows, linux and unix, the OS has a natural way of dealing with command line based program invokation, maybe on the madIntosh that can be done similarly, my memory escapes me on the subject (I do remember writing scripts).

The commands take in principle similar list form as under tcl, first element of the space seperated list is the command name, the rest options or arguments. In a shell a PATH needs to be taken into account, which points to the executable files on the disc, which is not the same under tcl. Also, list element seperation, and escape characters vary under tcl, *n?x, and windows, and as it happens, cygwin under windows.

To experiment with the exec command, start tcl or wish in the way you normally would, or the way it would automatically startup maybe, meaning from the same directory, environment and user rights, and make sure the console can be used, under windows and macIntosh (at least several verions ago) that is possible through:

   console show

under linux/unix, you may want to use the unixconsole script (which is on the wiki somewhere) to get a similar console (start it as first script, before other applications), now start by finding out wether the exec command can be used with some standart, simple shell commands, like

   exec pwd

on *n*x, or

   exec cmd /c dir

On windows.

On windows I prefer to have a recent powerfull version of cygwin around, which takes some download time and moderate disc space, but leaves you with a useable unix emulation and strong bash shell as it now also is in use on Linux.I have a changed disc organisation with akward or absent original cygwin paths/registry information, but I can still go to the partition where it is, go to the bin direction (with all the executables) and for instance

   exec ./bash -c "./ls ../"


...

   DO_TCL exec c:/cygwin/bin/bash -c "/usr/X11R6/bin/xterm -fn '-adobe-courier-*-r-*-*-*-140-*-*-*-*-*-*' -rightbar -sb -fg white -bg black  -display amachine.mshome.net:0 " &