Module: Ripl::ShellCommands

Defined in:
lib/ripl/shell_commands.rb

Overview

Allows for executing shell commands prefixed by a !.

Constant Summary collapse

PATHS =

The directories of $PATH.

ENV['PATH'].split(File::PATH_SEPARATOR)
EXECUTABLES =

Names and statuses of executables.

Hash.new do |hash,key|
  hash[key] = executable?(key) || PATHS.any? do |dir|
    executable?(File.join(dir,key))
  end
end
BUILTIN =

Builtin commands


      
        
BLACKLIST =
          

  

    
Blacklist of known commands that conflict with Ruby keywords.



  





  



        

        

      
        
PATTERN =
          

  

    
Regexp to recognize !commands.



  





  



        

        
/^![a-zA-Z][a-zA-Z0-9\._-]*/

      
    

  







  
    

      Class Method Summary
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      Instance Method Summary
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Class Method Details


    
      

  

  
    .cd(*arguments)  ⇒ Boolean 
  

  

  




  

    
Equivalent of the cd command, using Dir.chdir.



  





  
Parameters:


    
  
    
  • 
      
        arguments
      
      
        (Array<String>)
      
      
      
        —
        
    The arguments of the command.
    

    
      
    
    • 
  




Returns:


    
  
    
  • 
      
      
        (Boolean)
      
      
      
        —
        
    Specifies whether the directory change was successful.
    

    
      
    
    • 
  





  

    
      


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# File 'lib/ripl/shell_commands.rb', line 115

def self.cd(*arguments)
  old_pwd = Dir.pwd

  new_cwd = if arguments.empty?
              unless ENV['HOME']
                warn "cd: HOME not set"
                return false
              end

              ENV['HOME']
            elsif arguments.first == '-'
              unless ENV['OLDPWD']
                warn 'cd: OLDPWD not set'
                return false
              end

              ENV['OLDPWD']
            else
              arguments.first
            end

  Dir.chdir(new_cwd)
  ENV['OLDPWD'] = old_pwd
  return true
end

    		
  





    
      

  

  
    .exec(*arguments)  ⇒ Boolean 
  

  

  




  

    
Default command which executes a command in the shell.



  





  
Parameters:


    
  
    
  • 
      
        arguments
      
      
        (Array<String>)
      
      
      
        —
        
    The arguments of the command.
    

    
      
    
    • 
  




Returns:


    
  
    
  • 
      
      
        (Boolean)
      
      
      
        —
        
    Specifies whether the command exited successfully.
    

    
      
    
    • 
  





  

    
      


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# File 'lib/ripl/shell_commands.rb', line 102

def self.exec(*arguments)
  system(arguments.join(' '))
end

    		
  





    
      

  

  
    .executable?(path)  ⇒ Boolean 
  

  

  




  

    
Determines if an executable exists on the system.



  





  
Parameters:


    
  
    
  • 
      
        path
      
      
        (String)
      
      
      
        —
        
    The program path.
    

    
      
    
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Returns:


    
  
    
  • 
      
      
        (Boolean)
      
      
      
        —
        
    Specifies whether the executable exists.
    

    
      
    
    • 
  





  

    
      


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# File 'lib/ripl/shell_commands.rb', line 89

def self.executable?(path)
  File.file?(path) && File.executable?(path)
end

    		
  





    
      

  

  
    .export(*arguments)  ⇒ true 
  

  

  




  

    
Equivalent of the export or set commands.



  





  
Parameters:


    
  
    
  • 
      
        arguments
      
      
        (Array<String>)
      
      
      
        —
        
    The arguments of the command.
    

    
      
    
    • 
  




Returns:


    
  
    
  • 
      
      
        (true)
      
      
      
    
    • 
  





  

    
      


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# File 'lib/ripl/shell_commands.rb', line 149

def self.export(*arguments)
  arguments.each do |pair|
    name, value = pair.split('=',2)

    ENV[name] = value
  end
end

    		
  





    
      

  

  
    .parse(command)  ⇒ String+ 
  

  

  




  

    
Parses a Console command.



  





  
Parameters:


    
  
    
  • 
      
        command
      
      
        (String)
      
      
      
        —
        
    The Console command to parse.
    

    
      
    
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Returns:


    
  
    
  • 
      
      
        (String, Array<String>)
      
      
      
        —
        
    The command name and additional arguments.
    

    
      
    
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# File 'lib/ripl/shell_commands.rb', line 68

def self.parse(command)
  # evaluate embedded Ruby expressions
  command = command.gsub(/\#\{[^\}]*\}/) do |expression|
    eval(expression[2..-2],Ripl.shell.binding).to_s.dump
  end

  arguments = Shellwords.shellsplit(command)
  name      = arguments.shift

  return name, arguments
end

    		
  





    
  


  

    
Instance Method Details


    
      

  

  
    #loop_eval(input)  ⇒ Object 
  

  

  




  

    
Dynamically execute shell commands, instead of Ruby.



  





  
Parameters:


    
  
    
  • 
      
        input
      
      
        (String)
      
      
      
        —
        
    The input from the console.
    

    
      
    
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# File 'lib/ripl/shell_commands.rb', line 40

def loop_eval(input)
  if (@buffer.nil? && input =~ PATTERN)
    command = input[1..-1]
    name, arguments = ShellCommands.parse(command)

    unless BLACKLIST.include?(name)
      if BUILTIN.include?(name)
        arguments ||= []

        return ShellCommands.send(name,*arguments)
      elsif EXECUTABLES[name]
        return ShellCommands.exec(name,*arguments)
      end
    end
  end

  super(input)
end