How to execute linux commands from R via bash under the Windows Subsystem for Linux (WSL)?

Question

The WSL on Windows 10 allows execution of Linux commands and command-line tools via bash.exe. Very usefully, a Linux tool/command can be called from the Windows command-line (cmd.exe) by passing it as an argument to bash.exe like so:

bash.exe -c <linux command>

This is very useful because it should allow Windows-based scripts to combine Windows and Linux tools seamlessly.

Unfortunately, I have failed to call Linux commands from an R script (see below).

0) System

Win10 x64 + Anniversary Update + WSL installed

1) Comparison cases where calling Linux commands work

The following all work for me; shown here just with an example call to ls.

• from the windows command-line (cmd.exe prompt)

  bash -c "ls /mnt/a"
  

  bash -c "ls /mnt/a > /mnt/a/test.txt"
  

• Same works if started from WinKey + R

• Same works from within a .bat file.

• It can be called from compiled code. I tried with Delphi XE2 32-bit and 64-bit using ShellExecute:

  For example, these work (32 and 64 bit):

  ShellExecute (0, PChar('open'), PChar('cmd.exe'), PChar('/c c:\windows\system32\bash.exe -c "ls /mnt/a > /mnt/a/test.txt"'), nil, SW_SHOWNORMAL);
  

  Or (32-bit code):

  ShellExecute (0, PChar('open'), PChar('c:\windows\sysnative\bash.exe'), PChar('-c "ls /mnt/a > /mnt/a/test.txt"'), nil, SW_SHOWNORMAL);
  

  Or (64-bit code):

  ShellExecute (0, PChar('open'), PChar('c:\windows\system32\bash.exe'), PChar('-c "ls /mnt/a > /mnt/a/test.txt"'), nil, SW_SHOWNORMAL);
  

  All of these seem to work (and ShellExecute returns 42).

2) Failure to call Linux commands from R using R 3.3.1 x64

All of the below (and several similar things I've tried) fail with status 65535:

shell('c:/windows/system32/bash.exe -c "ls /mnt/a"', shell="cmd.exe", flag = "/c")

shell("ls", shell="c:/windows/system32/bash.exe", flag = "-c")

system('cmd /c c:/windows/system32/bash.exe -c "ls /mnt/a > /mnt/a/test.txt"')

system('bash -c "ls /mnt/a"')

system('c:/windows/system32/bash.exe -c "ls /mnt/a > /mnt/a/test.txt"')

3) Question

Given that examples under 1) work, I find 2) very puzzling. Am I missing anything obvious here?

I would be very grateful for a simple example where running a Linux command via bash.exe under WSL works.

Answer 1

Your failing examples should now be working correctly in Windows 10 Insider builds >= 14951 which introduced many "interop" improvements and new capabilities:

> system('bash -c "ls /"')

Generates:

bin   cache  dev  home  lib    media  opt   root  sbin  srv  tmp  var
boot  data   etc  init  lib64  mnt    proc  run   snap  sys  usr