Comment author: @diml

I tried something similar but couldn't reproduce the issue.

Here is what I tried:

$ cat echo_args.ml
let () = Array.iteri (Printf.printf "argv.(%d) = %S\n") Sys.argv
$ cat run_process.ml
let cmd = "C:/Documents and Settings/jdimino/echo args.exe"
let args = [ "arg1"
; "arg2"
; "C:/Documents and Settings/arg3"
]

let pid =
Unix.create_process cmd (Array.of_list (cmd :: args))
Unix.stdin Unix.stdout Unix.stderr

let _ = Unix.waitpid [] pid
$ ocamlopt -o "echo args.exe" echo_args.ml
$ ocamlopt -o run_process.exe unix.cmxa run_process.ml
$ cp "echo args.exe" "C:/Documents and Settings/jdimino/"
$ ./run_process.exe
argv.(0) = "C:/Documents and Settings/jdimino/echo args.exe"
argv.(1) = "arg1"
argv.(2) = "arg2"
argv.(3) = "C:/Documents and Settings/arg3"

Comment author: modlfo

Hi, here are more detailed steps of what I'm doing to reporduce the problem.

1.- Create a dir "C:\Path With Spaces"
2.- Create the following files:

Name: echoargs.bat

echo %1
echo %2
echo %3

Name: test.ml

let cmd = "C:/Path With Spaces/echoargs.bat"
let args = [ "arg1"
; "arg2"
; "C:/Documents and Settings/arg3"
]

let pid =
Unix.create_process cmd (Array.of_list (cmd :: args))
Unix.stdin Unix.stdout Unix.stderr

let _ = Unix.waitpid [] pid

3.- Compile test.native with:

$ ocamlbuild -use-ocamlfind -pkg unix test.native

4.- Execute ./test.native

The error I get is:

'C:/Path' is not recognized as an internal or external command,
operable program or batch file.

If I make the proposed change, works correctly. Note: in this case I'm calling a .bat file but I have the same result calling a regular exe file.

I'm using the MSVC 64 bits compiled with VS2013 running on Windows 10.

Comment author: @xavierleroy

This one is mysterious. The MSDN page says that the first parameter lpApplicationName can be NULL, in which case the beginning of the command-line determines the application name. But nowhere it says that a non-NULL lpApplicationName can cause problems with spaces in file names... Indeed, the "Security Remarks" section of the MSDN page cautions against passing NULL as lpApplicationName.

Any Windows expert here to help us understand?

Comment author: @xavierleroy

I can reproduce the problem when the executable is a .bat batch file, but not when it is a proper .exe executable.

I'm not even sure that the Win32 CreateProcess() system call is supposed to handle .bat files as executables. The examples I found on the Web involve calling cmd.exe as executable and "/c" "foo.bat" as arguments.

Resolving this PR as "not an OCaml issue".