reaper.ExecProcess . How?

[amagalma]

Hello!

In a few words, this works:

os.execute('start "" "'..path..'"')

But this doesn't:

reaper.ExecProcess('start "" "'..path..'"', 0)

Any ideas?

Thanks!

[cfillion]

start is a cmd.exe command, it's not a standalone program. Try this:

reaper.ExecProcess('cmd.exe /C start "" "'..path..'"', 0)

(of course this won't work on macOS and Linux, and mind the risk of command injection if variable `path` is arbitrary)

[amagalma]

Hmm, nope... still doesn't do anything! :S

[cfillion]

What does `path` contains and what does ExecProcess returns (it should be non-nil)?

This works here (opens C:\ in explorer.exe and returns "0\n"):

local path = 'C:\\'
reaper.ExecProcess('cmd.exe /C start "" "'..path..'"', 0)

[amagalma]

I'll check when I am back. Have to go now...

Thank you so much once more for the help!!!

[amagalma]

Return is 0 and path is "C:\Users\My Daw\Desktop"

PS.. Oh I see.. Maybe I have to escape every \ with a \

[amagalma]

Hmm.. Nope.. it wasn't that...

[amagalma]

Originally Posted by cfillion

What does `path` contains and what does ExecProcess returns (it should be non-nil)?

This works here (opens C:\ in explorer.exe and returns "0\n"):

local path = 'C:\\'
reaper.ExecProcess('cmd.exe /C start "" "'..path..'"', 0)

This worked, then I tried some things with my code (like escaping \ with \) and now it stopped working! :S Bug?

[cfillion]

One thing you can try is:

reaper.ShowConsoleMsg('cmd.exe /C start "" "'..path..'"\n')

...and check for oddities in the generated command line. Also try it directly in cmd.exe to bypass any risk of a bug in REAPER or your Lua script.

[amagalma]

Today it seems to work (I had to escape each \ with a \)

But, what I found is that if you enter a few times invalid arguments to reaper.ExecProcess then it stops working (this is what happened to me yesterday). A Reaper restart does not solve the problem!

[X-Raym]

Originally Posted by cfillion

of course this won't work on macOS and Linux

What would be the macOS equivalent then ? Not cmd.exe obviously.

EDIT: I found this info : https://forum.cockos.com/showpost.ph...37&postcount=6 but isnt the terminal path.

[Lokasenna]

If you just use / for path separators it should work on Windows, Mac, and Linux.

[cfillion]

Originally Posted by X-Raym

What would be the macOS equivalent then ? Not cmd.exe obviously.

To the start command (open a file or URL with the default application)? reaper.CF_ShellExecute.

Otherwise on macOS the program doing a similar job is "open" and on most Linux installations it is "xdg-open".

[X-Raym]

@Lokasenna
I have a big command with some echo command in it.


I'm trying to see if ExecProcess can take care of this echo call, so I can just map my big command to it.


How would you use echo within ExecProcess ?

My command is a succession of CLI program call followed by ' & ' (or '; ' on Mac), and some of this & or ; are followed by echo Something.

[cfillion]

Originally Posted by X-Raym

My command is a succession of CLI program call followed by ' & ' (or '; ' on Mac), and some of this & or ; are followed by echo Something.

/bin/sh -c 'command_a; command_b; command_c'

[X-Raym]

Otherwise on macOS the program doing a similar job is "open"

This doesn't work for 'echo' :S


Any other idea ?

[X-Raym]

@cfillion

reaper.ExecProcess("/bin/sh -c echo 1")
reaper.ExecProcess("/bin/sh -c echo '1'")

Both return

0\n\n

There is some progress though as previous code return error -999.

[cfillion]

The whole command line must be in a single argument for the -c option. So you'll need either quotes or to escape the spaces. Perhaps you could run bwfmetaedit directly with ExecProcess instead? (I don't remember if you tried that before)

reaper.ExecProcess("/bin/sh -c 'echo 1'", 0)

[X-Raym]

@cfillion
Oh yes ok, thanks ! Easy to get lost with all this escaping ^^


Though, it returns

0\n1\n1

How come ?


I guess I should only take care of the second line ?


EDIT: I guess these extra characters comme from ExecProcess which wrap the answer into an status code and a break line ?

[cfillion]

Originally Posted by X-Raym

EDIT: I guess these extra characters comme from ExecProcess which wrap the answer into an status code and a break line ?

Yup. REAPER puts the exit code of the process in first line (0 means success). Everything else is the actual output.

[X-Raym]

@cfillion
Understood.


I'll experiment this VS os.execute I currently use and see it it works as good for my case :P


Many thanks !

[_Stevie_]

Thanks guys, awesome discussion.
I have a variable called loopStartTime. How can I use it in the command line arguments?

That's the command:

reaper.ExecProcess('/Applications/ffmpeg/ffmpeg -ss loopStartTime') ...

[X-Raym]

@Stevie
Just concatanate the string and the variable using ".." operator

reaper.ExecProcess('/Applications/ffmpeg/ffmpeg -ss ' .. loopStartTime)

I think one of the best website (easy to read) website for lua basics is : https://www.tutorialspoint.com/lua/index.htm

[_Stevie_]

Thanks X-Raym! Will try that
The LUA guide looks very promissing as well!

[Lokasenna]

Originally Posted by X-Raym

I think one of the best website (easy to read) website for lua basics is : https://www.tutorialspoint.com/lua/index.htm

Definitely better than the X-Raym tutorials. Those videos are so bad that I actually forgot how to program after watching them. :P

[X-Raym]

@Lokasenna
Making bad video tutorials is my plan to annihilate the concurence. busted !

[amagalma]

What is the equivalent of this for Linux/OSX? :

(Windows)

reaper.ExecProcess('explorer.exe /e,/select,"' .. Path .. '"', -1)

Is this correct?

reaper.ExecProcess('/usr/bin/open -R "' .. Path .. '"', -1)

I want to open the file explorer with the file selected.


Thanks!

[Edgemeal]

maybe try this?...from ReaScript API,
boolean reaper.CF_LocateInExplorer(string file)
Select the given file in explorer/finder.

[amagalma]

Oh, I didn't know this API existed! Nice!
Thanks Edgemeal!