How to get the path to the current project file?

[#1]

If I have a script within a project (or perhaps a reference to the project in a script outside of the project), how to do I get the file path to where the project is saved on disk?  I'm interested in doing this with JSL, not interactively.

[#2]

// I had a similar problem with removing the file name from the file path 

Names Default To Here( 1 );

dt = Current Data Table();

current_file = dt << Get Path();

current_directory = Word([1 -2], current_file, "\");

// return the full string ([1 -1]), except for the last word ([1 -2])

data = Pick File(

"Select Data Files",

current_directory,

{"Excel|csv","JMP Files|jmp;jsl;jrn","All Files|*"},

1,

0,

"", multiple

);

[#3 · Accepted solution]

It turns out that message isn't available until (the future) JMP 18.2. 

In fact, I appears that I actually added it earlier this year in response to this question, but incorrectly marked it as having existing since JMP 14. Then I somehow forgot that I had done so, such that on reencountering this thread a few months later, I went looking for a solution and found the one I had recently created (but thought it was much older than it was). 

Sorry about that.

[#4]

Ah, I love the story.  No worries. I can only laugh because it sounds exactly like the sort of thing I would do.  The number of times I've written a function to solve a problem only to find I had made the exact same thing under a different name 6 months prior...

Anyway, I'm glad to hear the functionality is on the way!