Passing hashes as command-line parameters

Ruby
1

Is it not possible to pass hashes as command-line arguments to a Ruby
script?

Thanks,
Jeff

2

Jeff Leeman wrote:

Is it not possible to pass hashes as command-line arguments to a Ruby
script?

Like … ?

3

Well, what I’m looking for is to be able run something like:

ruby script/runner “SomeClassName.method_name({:some_key_1 =>
‘some_value_1’, :some_key_2 => ‘some_value_2’, :some_key_3 =>
‘some_value_3’})”

Joel VanderWerf wrote:

Jeff Leeman wrote:

Is it not possible to pass hashes as command-line arguments to a Ruby
script?

Like … ?

4

Jeff Leeman wrote:

Well, what I’m looking for is to be able run something like:

ruby script/runner “SomeClassName.method_name({:some_key_1 =>
‘some_value_1’, :some_key_2 => ‘some_value_2’, :some_key_3 =>
‘some_value_3’})”

You’re perfectly able to run something like that. See:

~> mkdir script
~> cat>script/runner
class SomeClassName
def self.method_name(hash)
p hash
end
end
eval ARGV[0]

~> ruby script/runner “SomeClassName.method_name({:some_key_1
=> ‘some_value_1’, :some_key_2 => ‘some_value_2’, :some_key_3
=> ‘some_value_3’})”
{:some_key_1=>“some_value_1”, :some_key_2=>“some_value_2”,
:some_key_3=>“some_value_3”}

HTH,
Sebastian

5

Which OS are you using? Also, are you running this from an IRC prompt
or a standard bash shell?

Thanks,
Jeff

Sebastian H. wrote:

Jeff Leeman wrote:

Well, what I’m looking for is to be able run something like:

ruby script/runner “SomeClassName.method_name({:some_key_1 =>
‘some_value_1’, :some_key_2 => ‘some_value_2’, :some_key_3 =>
‘some_value_3’})”

You’re perfectly able to run something like that. See:

~> mkdir script
~> cat>script/runner
class SomeClassName
def self.method_name(hash)
p hash
end
end
eval ARGV[0]

~> ruby script/runner “SomeClassName.method_name({:some_key_1
=> ‘some_value_1’, :some_key_2 => ‘some_value_2’, :some_key_3
=> ‘some_value_3’})”
{:some_key_1=>“some_value_1”, :some_key_2=>“some_value_2”,
:some_key_3=>“some_value_3”}

HTH,
Sebastian

6

Jeff Leeman wrote:

Which OS are you using?

Linux though that should really not make any difference. The ruby code I
posted will work on any platform (though you’d be using something other
than
cat to write the code into the file on systems without cat - but then
you’d
be doing that anyway, I only used cat so I could copy’n’paste the whole
thing
from my bash prompt).

Also, are you running this from an IRC prompt
or a standard bash shell?

bash. “~>” is my bash prompt.

7

Ok, interesting. I’m using a PC, and I tried the exact code that
Sebastian put together, and it runs fine in Cygwin, but does not work in
the command prompt window:

C:\rails_app>jruby script\runner “SomeClassName.method_name({:some_key_1
=> ‘some_value_1’, :some_key_2 => ‘some_value_2’})”
script\runner:6: (eval):1: , unexpected ‘=’ (SyntaxError)

I guess I don’t know the command prompt language too well, but there’s
probably some special way things have to be delimited with quotes.

-Jeff

Joel VanderWerf wrote:

Jeff Leeman wrote:

Like … ?

You could just eval ARGV[0] in this case.

$ ruby -e ‘p eval(ARGV[0])’ ‘{:foo => :bar}’
{:foo=>:bar}

8

Jeff Leeman wrote:

C:\rails_app>jruby script\runner “SomeClassName.method_name({:some_key_1
=> ‘some_value_1’, :some_key_2 => ‘some_value_2’})”
script\runner:6: (eval):1: , unexpected ‘=’ (SyntaxError)

Try putting p ARGV[0] before the eval and see what that outputs. That
way you
can see if and how cmd butchers the argument.

9

Jeff Leeman wrote:

Like … ?

You could just eval ARGV[0] in this case.

$ ruby -e ‘p eval(ARGV[0])’ ‘{:foo => :bar}’
{:foo=>:bar}