Feature #1482: Kernel.exec doesn't respect COMSPEC environment variable on Windows

• Status: Rejected
• Assignee: nobu (Nobuyoshi Nakada)
• Target version: 2.2.0

[dolzenko (Evgeniy Dolzhenko)]

Here is pretty convoluted test case:

puts ENV["COMSPEC"] # => "C:\WINDOWS\system32\mycmd.exe"

File.open("1.bat", "w") { |f| f.write("time") } # create test batch file with command which waits for user input
 
Kernel.exec("1.bat") # now the process tree inspection shows that the "C:\WINDOWS\system32\cmd.exe" is still used to interpret 1.bat

[ujihisa (Tatsuhiro Ujihisa)]

• Status changed from Open to Assigned
• Assignee set to usa (Usaku NAKAMURA)

[usa (Usaku NAKAMURA)]

• Status changed from Assigned to Feedback

This is the spec of Windows itself.
Should we change the behavior with deviating from OS standard way?

[usa (Usaku NAKAMURA)]

• Priority changed from Normal to 3
• Target version deleted (Ruby 1.8.7)

[mame (Yusuke Endoh)]

Hi, usa

Should we keep this ticket open?

I'd like to close this ticket because there is no feedback from OP.
If you'll still wait, please change the target to 1.9.x.

--
Yusuke Endoh [e-mail]

[jonforums (Jon Forums)]

While I didn't report the behavior, using the code from the OP but using the TCC LE shell from http://www.jpsoft.com/tccledes.htm which has a COMSPEC of

[C:\Users\Jon\Documents]echo %COMSPEC%
C:\Program Files\JPSoft\TCCLE11\TCC.EXE

and using Process Explorer from http://technet.microsoft.com/en-us/sysinternals/bb896653.aspx I get the same results as the OP, the TCC LE process starts a Ruby process that starts a C:\WINDOWS\system32\cmd.exe process to interpret the bat.

I'm curious, where is it described that this behavior is the spec of Windows itself? I'm not familiar with this from the DOS or WScript/CScript scripting perspective.

OTH, if Kernel.exec would be changed to honor COMSPEC, would it handle spaces in the path correctly when using shells such as TCC LE?

Jon

[nobu (Nobuyoshi Nakada)]

Hi,

At Wed, 31 Mar 2010 01:31:39 +0900,
Jon Forums wrote in [ruby-core:29147]:

I'm curious, where is it described that this behavior is the
spec of Windows itself? I'm not familiar with this from the
DOS or WScript/CScript scripting perspective.

It's depend on "the association of file extension to programs".

OTH, if Kernel.exec would be changed to honor COMSPEC, would
it handle spaces in the path correctly when using shells such
as TCC LE?

It's already done if you pass them properly.

--
Nobu Nakada

[znz (Kazuhiro NISHIYAMA)]

• Category set to core
• Target version set to 2.0.0

[dolzenko (Evgeniy Dolzhenko)]

Documentation for exec method says:

• The standard shell means always "/bin/sh" on Unix-like systems,
• ENV["RUBYSHELL"] or ENV["COMSPEC"] on Windows NT series, and
• similar.

but I still can't get it to run my customized interpreter.

When you say that it depends on "the association of file extension to programs" does
that mean association of batch files? I tried to change this to my customized
interpreter (Control Panel\Programs\Default Programs\Set Associations in Windows 7)
and Ruby is still running cmd.exe (in the original test case).

[mame (Yusuke Endoh)]

Hello,

Usak-san or nobu, could you tell me the status?

--
Yusuke Endoh [e-mail]

[usa (Usaku NAKAMURA)]

• Status changed from Feedback to Assigned

Now ruby recognize batch files as "programs", so they are simply passed to
CreateProcess() API.
So, current behavior is Windows' spec.

However, I suspect that this (= simply being passed to CreateProcess API) is not intended.
I'll discuss about it with nobu next week.

[nobu (Nobuyoshi Nakada)]

• File 0001-win32.c-use-COMSPEC.patch 0001-win32.c-use-COMSPEC.patch added

Does this patch help?

[usa (Usaku NAKAMURA)]

Can you write a test for this patch, nobu?
If so, please commit them(=this patch and the test).

[usa (Usaku NAKAMURA)]

• Assignee changed from usa (Usaku NAKAMURA) to nobu (Nobuyoshi Nakada)
• Priority changed from 3 to Normal

[mame (Yusuke Endoh)]

Nobu, did you?

--
Yusuke Endoh [e-mail]

[ko1 (Koichi Sasada)]

• Target version changed from 2.0.0 to 2.1.0

ping -> nobu.

[nobu (Nobuyoshi Nakada)]

Unfortunately, I've lost my topic branch for this issue, so have to rewrite from the previous patch again.

[hsbt (Hiroshi SHIBATA)]

• Target version changed from 2.1.0 to 2.2.0

[mame (Yusuke Endoh)]

Nobu, are you still willing to reimprement the patch for this issue?

[nobu (Nobuyoshi Nakada)]

• Description updated (diff)

At least on Windows 10, doesn't CreateProcess() honor COMSPEC variable now?
1.rb

p $$; exec("./1.bat")

$ COMSPEC="./miniruby.exe -e 'p $$, Process.ppid, ARGV'" ./miniruby -v ./1.rb 
ruby 2.5.0dev (2017-10-19 trunk 60215) [x64-mswin64_140]
1524
9148
1524
["/c", ".\\1.bat"]

[nobu (Nobuyoshi Nakada)]

• Status changed from Assigned to Rejected

Seems Microsoft has fixed Windows.