Class: Rubish::Command

Inherits:
UnixExecutable show all
Defined in:
lib/rubish/command.rb

Direct Known Subclasses

CommandBuilder

Constant Summary

Constants inherited from UnixExecutable

UnixExecutable::EIO

Instance Attribute Summary collapse

Attributes inherited from Executable

#working_directory

Instance Method Summary collapse

Methods inherited from UnixExecutable

#exec, #exec!

Methods inherited from Executable

#awk, #cd, #each, #each!, #err, #err=, #exec, #exec!, #first, #head, #i, #i=, #io, #last, #map, #map!, #o, #o=, #sed, #tail

Constructor Details

#initialize(cmd, args) ⇒ Command

Returns a new instance of Command.



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# File 'lib/rubish/command.rb', line 6

def initialize(cmd,args)
  @quoted = false
  @args = args
  @cmd = cmd.to_s
end

Instance Attribute Details

#args ⇒ Object (readonly)

Returns the value of attribute args.



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# File 'lib/rubish/command.rb', line 4

def args
  @args
end

#cmd ⇒ Object (readonly)

Returns the value of attribute cmd.



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# File 'lib/rubish/command.rb', line 4

def cmd
  @cmd
end

#quoted ⇒ Object (readonly)

if true, arguments for exec are not shell expanded.



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# File 'lib/rubish/command.rb', line 5

def quoted
  @quoted
end

Instance Method Details

#%(arg) ⇒ Object 



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# File 'lib/rubish/command.rb', line 68

def %(arg)
  @args = [arg]
  self
end

#+(arg) ⇒ Object 



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# File 'lib/rubish/command.rb', line 63

def +(arg)
  @args << arg
  self
end

#exec_with(i, o, e) ⇒ Object 



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# File 'lib/rubish/command.rb', line 12

def exec_with(i,o,e)
  normalize_args!
  unless pid = Kernel.fork
    # child
    system_exec(i,o,e)
  else
    return [pid]
  end
end

#normalize_args!(args = @args) ⇒ Object 



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# File 'lib/rubish/command.rb', line 73

def normalize_args!(args=@args)
  args.map! do |arg|
    case arg
    when Symbol
      "-#{arg.to_s[0..-1]}"
    when Array
      # recursively flatten args
      normalize_args!(arg)
    when String
      arg
    else
      raise "argument to command should be one of Symbol, String, Array "
    end
  end
  args.flatten!
  args
end

#q ⇒ Object 



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# File 'lib/rubish/command.rb', line 53

def q
  @quoted = true
  self
end

#q! ⇒ Object 



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# File 'lib/rubish/command.rb', line 58

def q!
  @quoted = false
  self
end

#system_exec(i, o, e) ⇒ Object

this method should be called after fork



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# File 'lib/rubish/command.rb', line 23

def system_exec(i,o,e)
  begin
    # dup2 the given i,o,e to stdin,stdout,stderr
    # close all other file
    Rubish.set_stdioe(i,o,e)
    # exec the command
    if self.quoted
      # use arguments as is
      Kernel.exec self.cmd, *args
    else
      # want shell expansion of arguments
      Kernel.exec "#{self.cmd} #{args.join " "}"
    end
  rescue
    # with just want to kill the child
    # process. When something goes wrong with
    # exec. No cleanup necessary.
    #
    # There's a weird problem with
    # Process.exit(non_zero) raising SystemExit,
    # and that exception somehow reaches the
    # parent process.
    Process.exit!(1)
  end
end

#to_s ⇒ Object 



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# File 'lib/rubish/command.rb', line 49

def to_s
  self.inspect
end