How to tell if script running under rubyw vs ruby?

[Joe Swatosh]

I spent some time poking around in Config, but so far this is the the
only thing I've found that works:

begin
puts 'this is a test'
# here is ruby
rescue
# here is rubyw
end

And I really don't love the side effect when using ruby. Please tell
me there is a better way.

Thanks,

 

[Sean O'Halpin]

I spent some time poking around in Config, but so far this is the the
only thing I've found that works:

begin
puts 'this is a test'
# here is ruby
rescue
# here is rubyw
end

And I really don't love the side effect when using ruby. Please tell
me there is a better way.

Thanks,

As you've found out, stdout doesn't work under rubyw because all three
usual streams (stdout, stdin and stderr) are closed in a Windows exe.
I don't have a Window box handy to test, but you could try checking
the value of STDOUT under rubyw - it's probably nil or something like
that or you may get .eof? == true. Only a heuristic, but should serve
to distinguish between your two use cases.

Regards,
Sean

 

[Sebastian Hungerecker]

I don't have a Window box handy to test, but you could try checking
the value of STDOUT under rubyw - it's probably nil or something like
that or you may get .eof? == true.

Alternatively you could check for STDOUT.closed? or !STDOUT.tty?
One of those three should work at least.


HTH,
Sebastian

 

[Nobuyoshi Nakada]

Hi,

At Sun, 11 May 2008 02:59:07 +0900,
Joe Swatosh wrote in [ruby-talk:301402]:

I spent some time poking around in Config, but so far this is the the
only thing I've found that works:

It depends on what you want to know. If it is

a) whether running with or without a console window, you can't
open "CONIN$" and "CONOUT$" without it.

begin
open("CONIN$") {}
# here is ruby
rescue
# here is rubyw
end

b) whether running with opened STDIN/STDOUT/STDERR, STDIN.stat
and so on fail with EBADF if it is not opened.

c) or, whether running executable is linked in GUI mode or CUI
mode, you might have to parse the exe header. (imagehlp.dll
or something may be needed.)

 

[Joe Swatosh]

Hi,

At Sun, 11 May 2008 02:59:07 +0900,
Joe Swatosh wrote in [ruby-talk:301402]:

I spent some time poking around in Config, but so far this is the the
only thing I've found that works:

It depends on what you want to know. If it is

a) whether running with or without a console window, you can't
open "CONIN$" and "CONOUT$" without it.

begin
open("CONIN$") {}
# here is ruby
rescue
# here is rubyw
end

b) whether running with opened STDIN/STDOUT/STDERR, STDIN.stat
and so on fail with EBADF if it is not opened.

c) or, whether running executable is linked in GUI mode or CUI
mode, you might have to parse the exe header. (imagehlp.dll
or something may be needed.)

Thanks Sean.
I should have mentioned that testing for defined?, nil?, and eof?
weren't helpful.

Thanks Sebastian.
No joy on .tty? or .closed? either.

Nobu rocks again!
It is b) We are using some gems that might puts or warn when they are
loaded, so when running under rubyw we are planning to redirect them
to a log file, but we don't want to mess with anything when running
under ruby.

Thanks again everyone.