Bash in Git for Windows: Weirdness when running a command with CMD.exe /C with args

Question

This is more of an annoyance rather than a problem but I would very much like to understand the semantics here.

All I want to do is to run an arbitrary command on a

Answer 1

As I explain here, there is an additional alternative when using modern Git for Windows' bash

MSYS_NO_PATHCONV=1 cmd /c echo test

Explanation of each attempt

TL;DR

The unfortunate answer is in Windows, there are many ways arguments can be parsed, and you have to format your output in bash in such a way that is will be reparsed by the windows program it the way it expects

Second, third, and forth attempts are all actually identical

This is the same as (in cmd) > cmd "/c echo test". Windows cmd only uses " quotes, so somewhere between the runtimes, your (in bash) $ cmd '/c echo test' converts all the arguments to "/c echo test" which is happily parses.

Since from a bash point of view, the 2nd/3rd/4th attempt are all the same, they all give the same response. The surprise " is due to how windows parsing only using " and not ', hence it is the same as > cmd "/c echo test"

Fifth attempt

$ cmd "/c echo" test is the same as > cmd /c echo" test. (I'm guessing: The space after the /c is optional, so cmd isn't confused by /c echo being the space being literal due to the first quote.) So it is trying to execute the command echo" test which doesn't exist. The space is interpreted as literal because of the quote. Likewise, if you had done $ cmd "/c echo "test you would get the output "test, because the space is no longer being treats as literal, and no longer part of the command echo

Note: > cmd "/c echo" test and > cmd /c echo" test error the same. My guess here is that cmd parsed everything after the /c on its own, so the initial " has no affect, as parsing starts all over again. Chalk that up to special cmd weirdness.

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This can actually be reproduced using python for windows, which has nothing to do with msys/mingw/git/bash/glibc/etc...

python -c "import subprocess; subprocess.Popen(['cmd', '/c echo test'])"