Changing the shell for system commands to mingw-w64

Hi community,

I've been trying to use 'system' commands in MATLAB to execute operating system command (from MRtrix3 to be specific). However, to do so I need to change the shell from default to mingw-w64 for my windows laptop, which I've been struggling to do. While I've tryied things like:

setenv MATLAB_SHELL C:\msys2\mingw64.exe

inside my script before calling system comamnds, it doesn't actually work.

I wonder what can I do about this / what i did wrong.

Many thanks in advance

[dpb]

I've not tried to renew that quest for a number of years but I reached the conclusion MATLAB / MW simply refuse to acknowledge there is any other possible shell and simply dispatches CMD.EXE regardless.

Even setting a default user shell at the SYS level didn't make any difference in earlier releases and on pre-Win10 OS'es; I doubt any enlightenment has since changed anything.

I just gave it up as a lost cause despite the loss of functionality and hadn't even tried with Win10.

I suspect it will become even more interesting when folks begin wondering why PowerShell isn't spawned... :)

[Walter Roberson]

Using the SHELL environment variable is only supported on MacOS and Linux

[dpb]

Is that documented anywhere, Walter? And what makes them special?

[Walter Roberson]

Bottom of the system() page discusses MATLAB_SHELL and SHELL environment variables in the Unix section.

Answer 1

[Shivam]

Hi, you can override an environment variable in the system command by modifying the command string. In your case, you want to set the MATLAB_SHELL variable to the path of the MinGW-w64 shell before executing your command.

Here's an example of how you can modify your system command to set the MATLAB_SHELL variable:

myPath = 'C:\msys2\mingw64.exe';  % Path to the MinGW-w64 shell
dosCommand = 'pacman -Su'; % For example 
system(['set MATLAB_SHELL=' myPath ' && ' dosCommand])

[Jeremy Hughes]

MATLAB_SHELL only has an effect on unix platforms. Windows only supports CMD

[dpb]

" Windows only supports CMD"

More precisely, it's that "MATLAB under Windows...", Windows itself does support other command processors such as JP Software's TCC. I've railed about this limitation for years as well...it is a real pain to not be able to use the tools at one's disposal for one's own purposes even if others might not choose to have the other toolset.

Answer 2

[Jeremy Hughes]

On Windows, the only way to do this is to launch the desired shell with the command as an argument.

I couldn't (quickly) find the argumnents for mingw64 how to do this, but for powershell this would look like:

dosCommand = "dir"; % Dos Command needs to be escaped correctly to pass quotes if needed. 
wrappedCommand = sprintf('powershell --command "%s"',dosCommand)

wrappedCommand = 'powershell --command "dir"'

system(wrappedCommand)

[Mariam]

Hello Jeremy, I tried this approach by running:

command = "echo $PATH";
wrappedCommand = sprintf('mingwenv.cmd --command "%s"',command)
system(wrappedCommand)

but it only opens the mingwenv window and doesnt run any command i give it. do you have any idea what can be done in this case?