How to execute some procedure in all ruby files in current directory?

Question

I'm new to Ruby - I'm having troubles on every step...

Imagine a Ruby script main.rb and a lot of unknown script files script1.rb ... scriptN.rb. Each scriptX.rb contains unique module with one procedure needs to be executed:

Module X  
  def some_procedure(i)  
    puts "{#i} Module X procedure executed successfully!"  
  end  
end

All I need is to:

1. iterate over all files in current directory
2. if current file has name like /^script.*?\.rb$/
3. then load it and execute some_procedure

How can I do it in main.rb ?

Thank you in advance!

Answer 1

Choose from these great answers in SO on loading the files: http://stackoverflow.com/questions/735073/best-way-to-require-all-files-from-a-directory-in-ruby

Then in your files, just have them execute on load, rather than on a method call.

Answer 2

The problem might be that, when a file is required, it doesn't return the list of modules (or, in general, constants) which it defines. So, unless you don't know which module a script has defined, you will not know where to pass your some_procedure message.

As a workaround, you may try getting the list of defined constants before and after the script was required, find a difference, i.e. list of constants during require, and iterate through all of them, checking which one implements the method you need.

Answer 3

First, we need to put some restriction:

• Every file script_my1.rb will have the module named Script_my1. I.e. first letter capitalized, all other letters - lowercase.

Create two files script_my1.rb and script_my2.rb as follows:

---script_my1.rb:

module Script_my1  
  @value = 0  

  def self.some_procedure(i)  
    puts "#{i} my1 executed!"  
    @value = i  
  end  

  def self.another_procedure()  
    return @value  
  end  
end  

---script_my2.rb:

module Script_my2  
  @value = 0

  def self.some_procedure(i)  
    puts "#{i} my2 executed!"  
    @value = i  
  end  

  def self.another_procedure()  
    return @value  
  end  
end  

Now the main script, that loads and executes some_procedure() in each module, and then another_procedure().

Please notice, that each module can have separated variables with the same name @value.

Moreover, I think every module can be executed in a separate thread and have access to global variables, but I have not tested it yet.

---main.rb:

# Load all files from the current directory  
# with name like script_xxx.rb  
i = 1  
result = nil  
Dir['./script_*.rb'].each { |f|  
  next if File.directory?(f)  

  require (f)  
  moduleName = f[2,f.length].rpartition('.rb')[0].capitalize  
  eval ( "#{moduleName}.some_procedure(%d)" % i )  
  eval ( "result = #{moduleName}.another_procedure()" )  
  puts result  
  i = i + 1  
}  

Output of this program is:

1 my1 executed!
1
2 my2 executed!
2

That is all!

Answer 4

Some improvement to previous solution can be made. If we want to avoid special naming, we can use global hash to store procedure's names. Each loaded script_xx.rb file would register it's own procedures in this global hash.

Please notice, that in this case we make two cycles:

1. first we load all files script_xx.b

   every file while loading will register it's procedures in $global_procs array.

2. then iterate over all entries in $global_procs to execute all registered procedures via eval()

Hope, this is a more 'ruby-like' solution!

---*script_my1.rb*

module My1  
  @value = 0  

  def self.some_procedure(i)  
    puts "#{i} my1 executed!"  
    @value = i  
  end  

  def self.another_procedure()  
    return @value  
  end  
end 

$global_procs << { 'module' => 'My1',
  'some_procedure' => 'My1.some_procedure',
  'another_procedure' => 'My1.another_procedure' }

---*script_my2.rb*

module MMM2  
  @value = 0

  def self.some_procedure(i)  
    puts "#{i} MMM2 executed!"  
    @value = i  
  end  

  def self.another_procedure()  
    return @value  
  end  
end  

$global_procs << { 'module' => 'MMM2',
  'some_procedure' => 'MMM2.some_procedure',
  'another_procedure' => 'MMM2.another_procedure' }

---main.rb

# Create global array for holding module's info
$global_procs = []

Dir['./script_*.rb'].each { |f|  
  next if File.directory?(f)  
  require (f)  
}

i = 1  
result = nil  

$global_procs.each { |p|
  puts "Module name: " + p['module']
  eval(p['some_procedure']+'(i)')
  result = eval(p['another_procedure']+'()')
  puts result  
  i = i + 1  
}