The common idiom
if __FILE__ == $0 then ...
gives bugs when $0 is not what one would expect, for instance under a
debugger, or in rubyscript2exe, etc.
There should be a primitive test
if <nice name to be found> then...
--
Posted via http://www.ruby-forum.com/.
require 'English'
if __FILE__ == $PROGRAM_NAME
...
end
Blessings,
TwP
On 7/2/07, Michel Demazure <michel@demazure.com> wrote:
The common idiom
if __FILE__ == $0 then ...
gives bugs when $0 is not what one would expect, for instance under a
debugger, or in rubyscript2exe, etc.There should be a primitive test
if <nice name to be found> then...
rcov provides for this case a special switch --replace-progname that
does what the name says. Unfortunately, sometimes there's still a
mismatch between those two:
one is ./something.rb while the other is just something.rb. Therefore
I use the following variation of the idiom (I haven't checked this
under debugger or any other prog):
if File.expand_path(__FILE__)==File.expand_path($0)
I have posted a patch for ruby-prof that adds a similar switch and it
has been accepted.
Anyway, $0 seems to be a normal variable that you can set to anything
you want, so creating a small wrapper script should not be a problem.
E.g.
$0 = ARGV.shift
require $0
On 7/2/07, Michel Demazure <michel@demazure.com> wrote:
The common idiom
if __FILE__ == $0 then ...
gives bugs when $0 is not what one would expect, for instance under a
debugger, or in rubyscript2exe, etc.There should be a primitive test
if <nice name to be found> then...
Tim Pease wrote:
On 7/2/07, Michel Demazure <michel@demazure.com> wrote:
The common idiom
if __FILE__ == $0 then ...
gives bugs when $0 is not what one would expect, for instance under a
debugger, or in rubyscript2exe, etc.There should be a primitive test
if <nice name to be found> then...require 'English'
if __FILE__ == $PROGRAM_NAME
...
end
Does that solve the problem? Isn't that vulnerable to the same issues as just using $0?
--
Alex
be careful, $0 is not a normal variable:
cfp:~ > cat a.rb
$0 = 'foobar'
puts `ps wwwaux|grep foobar`
cfp:~ > ruby a.rb
ahoward 10371 2.6 -0.1 29204 1388 p2 S+ 12:41AM 0:00.01 foobar
ahoward 10372 1.4 -0.0 27728 584 p2 S+ 12:41AM 0:00.00 sh -c ps wwwaux|grep foobar
ahoward 10374 1.2 -0.0 27368 448 p2 S+ 12:41AM 0:00.00 grep foobar
it actually assigns to c's argv
-a
On Jul 2, 2007, at 3:03 PM, Jano Svitok wrote:
Anyway, $0 seems to be a normal variable that you can set to anything
you want, so creating a small wrapper script should not be a problem.
E.g.$0 = ARGV.shift
require $0
--
we can deny everything, except that we have the possibility of being better. simply reflect on that.
h.h. the 14th dalai lama
You're correct! That does not solve the problem. 
Hmmm ... the solution I use most often is to have a top-level function
that runs the application. This top-level function is called by a
separate Ruby script.
class MyApp
def self.run( args )
new(args).run
end
...
end
And in an executable file called "my_app"
#!/usr/bin/env ruby
require 'MyApp'
MyApp.run ARGV
I try to avoid the __FILE__ == $0 idiom when I distribute code. You
run into the problems the original poster pointed out, and rubygems
also wrappers up all your executables with it's own special calling
semantics (provides compatibility between windows / *nix).
Not the answer you want to hear, but, "don't do that". Sorry
TwP
On 7/2/07, Alex Young <alex@blackkettle.org> wrote:
Tim Pease wrote:
> On 7/2/07, Michel Demazure <michel@demazure.com> wrote:
>> The common idiom
>> if __FILE__ == $0 then ...
>> gives bugs when $0 is not what one would expect, for instance under a
>> debugger, or in rubyscript2exe, etc.
>>
>> There should be a primitive test
>> if <nice name to be found> then...
>>
>
> require 'English'
>
> if __FILE__ == $PROGRAM_NAME
> ...
> end
>
Does that solve the problem? Isn't that vulnerable to the same issues
as just using $0?
Solve what problem? The code is doing what you asked it to do, that isn't a problem, that's programming.
The code clearly reads "if this file is the program" which is NOT the case when run under a debugger. I'm not sure what rubyscript2exe generates, but my guess is that can be solved on their end somehow. I generally don't want that code to run when I'm poking around in a debugger or something similar. If I do, I set the values inside the debugger and don't worry about it.
On Jul 2, 2007, at 11:11 , Alex Young wrote:
Tim Pease wrote:
On 7/2/07, Michel Demazure <michel@demazure.com> wrote:
The common idiom
if __FILE__ == $0 then ...
gives bugs when $0 is not what one would expect, for instance under a
debugger, or in rubyscript2exe, etc.require 'English'
if __FILE__ == $PROGRAM_NAMEDoes that solve the problem? Isn't that vulnerable to the same issues as just using $0?