How to run code (in any language) in external processes

[Edward K. Ream]

It's dead easy to run code in an external process, so that Leo doesn't hang.  Just use g.execute_shell_commands. 

For example, I can test Qt Quick code without hanging Leo like this:

g.execute_shell_commands('qmlscene /test/qml_test.qml')

The "work flow" is as follows:

1. Define "@file /test/qml_test.py" containing the code to be tested.  You can use @others and section references as always, but you must define c, g and p yourself.

2. Define @button qml-test containing just the call to g.execute_shell_commands given above.

3. The @button node defines a new command, "qml-test".  After running the command from the minibuffer, you can re-run the test using Ctrl-P, repeat-complex-command.

Similarly, Leo can run code in any language.  Just do something like this:

g.execute_shell_commands([
    '<path to>compiler <path to>program',
    '<command to run> <resulting program>',
])

Edward

P. S. g.execute_shell_commands_with_options provides more flexibility: it inits the environment and then calls g.execute_shell_commands.  See the source code in leoGlobals.py for details. For the ultimate in flexibility, use subprocess.popen.

EKR

[Matt Wilkie]

It's dead easy to run code in an external process, so that Leo doesn't hang.  Just use g.execute_shell_commands. 

this is timely! thanks.