Can't run .cmd files in Windows without the full filename

[nateGeorge]

I'm in Windows 10, trying to run the orca CLI from plotly (plotly::orca()) which uses processx::run(). It doesn't work (see issue here: plotly/plotly.R#1741). I noticed that run('orca.cmd') works. Any ideas why it doesn't work with simply run('orca') and how it can be fixed?

[nateGeorge]

Alright, I figured out how to get the orca CLI to work, although this doesn't fix the .cmd file issue. Originally, I had installed orca with conda: conda install -c plotly plotly-orca. This installed orca.cmd to C:\Users\myusername\Anaconda3\orca.cmd. I had to install orca from the windows release (https://github.com/plotly/orca/releases/tag/v1.3.1), which it installed to C:\Users\myusername\AppData\Local\Programs\orca.exe. Then I added this path to my System Path env variable, logged out and back in, and it worked.

For some reason, in Windows, processx doesn't seem to work with .cmd files without using the extension, but can run .exe files with or without the extension.

[gaborcsardi]

processx does not look for .bat or .cmd files currently, only .com and .exe. It seems that cmd.exe looks for .bat and .cmd after .exe, so we could support it without breaking things, even though in theory this is a breaking change.

[gaborcsardi]

[accidental close]

This needs to be added here:

processx/src/win/processx.c

Lines 659 to 666 in 447dab4

	/* Try .exe extension */
	result = processx__search_path_join_test(dir, dir_len,
	name, name_len,
	L"exe", 3,
	cwd, cwd_len);
	if (result != NULL) {
	return result;
	}

with a unit test ideally.

[gaborcsardi]

Actually, the documentation of CreateProcess() says, that it cannot open .bat and .cmd files directly, and you need to start a shell:

To run a batch file, you must start the command interpreter; set lpApplicationName to cmd.exe and set lpCommandLine to the following arguments: /c plus the name of the batch file.

https://docs.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-createprocessw

This is clearly not what we are seeing, but it is still not a good idea to implement something that should not work according to the docs.

So I'll close this now.

[pokyah]

Hi!

I'm facing the same problem as @nateGeorge while using orca called by an R script from KNIME.

R throws me the following error:

command orca not found @win/processx.c:983 (processx_exec)

I can get rid of it by tweaking https://github.com/pokyah/plotly/blob/master/R/orca.R at line 97 so that it call system instead of processx. However I consider this as a hotfix rahter than a permanent solution.

How could we efficiently investigate and solve the problem on the processx side?

I'll be keen to help.

Thanks

[gaborcsardi]

@pokyah This is how you can start a .cmd file: https://processx.r-lib.org/reference/process.html#batch-files