CODEWITHSUNDEEP
rubyirb
xst
xst

Reputation: 3046

irb access pre-load script local variables

i'm using irb -I . -r script.rb to require a script before starting an interactive session. functions defined in the global scope are available but variables aren't unless they are declared with @

is there a way to access local variables defined in the global context of a script or a better way to do this

script.rb: 

def func() "..." end
a = "str"
@b = 1

then after irb starts:

irb(main):001:0> a

NameError: undefined local variable or method `a' for main:Object
    from (irb):1
    from /usr/bin/irb:11:in `<main>'

irb(main):002:0> @b

=> 1

irb(main):003:0> func

=> "..."

i'm assuming that the script's contents are executed as if defined in a function (eg: main in C-type languages) and so the variables at the global context are local variables that are not accessible outside that scope

so do most people use @ variables when writing their scripts?

the use-case is narrow in scope (script development) and the solution is trivial (search-replace any variable with @variable), but I'm learning the semantics of the language and I'm curious about this. Can't the execution context be exposed and merged into the current context somehow?

Upvotes: 0

Views: 348

Answers (2)

Superp
Superp

Reputation: 11

Maybe binding.irb is what you are looking for.

script.rb:

def func() "..." end
a = "str"
@b = 1
binding.irb

From the documentation:

Opens an IRB session where binding.irb is called which allows for interactive debugging. You can call any methods or variables available in the current scope, and mutate state if you need to.

Upvotes: 1

J&#246;rg W Mittag
J&#246;rg W Mittag

Reputation: 369556

No. You can't access local variables from a different scope. That's the whole point of local variables: they are local to the scope they are defined in.

In this case, a is local to the script body of script.rb.

Upvotes: 3

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