Class: BlueShell::Bash

Inherits:
Object
  • Object
show all
Defined in:
lib/blue_shell/bash.rb

Constant Summary collapse

BufferedReader = 
java.io.BufferedReader
InputStreamReader = 
java.io.InputStreamReader

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Bash

Returns a new instance of Bash.



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# File 'lib/blue_shell/bash.rb', line 12

def initialize
  @hooks     = { stderr: [], stdout: [] }
  @executing = false
end

Instance Attribute Details

#err ⇒ Object (readonly)

Returns the value of attribute err.



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# File 'lib/blue_shell/bash.rb', line 10

def err
  @err
end

#exit ⇒ Object (readonly)

Returns the value of attribute exit.



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# File 'lib/blue_shell/bash.rb', line 10

def exit
  @exit
end

#out ⇒ Object (readonly)

Returns the value of attribute out.



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# File 'lib/blue_shell/bash.rb', line 10

def out
  @out
end

Instance Method Details

#add_hook(type, lambda) ⇒ Object

Add a lambda to execute on every line of stdout. The lambda should accept one parameter, a string, the line of output.

Examples:

Pushing to the console

lambda { |line| puts line }

Parameters:

  • the (Symbol) —

    stream to hook into (:stderr or :stdout)

  • the (Lambda) —

    code to execute



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# File 'lib/blue_shell/bash.rb', line 23

def add_hook(type, lambda)
  @hooks[type] << lambda
end

#execute!(command, timeout = 30) ⇒ Object

Execute the given command. Will block until the command completes. param [String] the command to execute in bash param [Integer] the number of seconds to wait for it to complete



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# File 'lib/blue_shell/bash.rb', line 30

def execute!(command, timeout = 30)
  # Executing via a file seems clunky, but it is a good way to
  # ensure everything happens exactly as we expect it to without 
  # trying to deal with escaping the world properly.
  file = Tempfile.new('command')

  begin
    file << command
    file.flush

    Timeout::timeout(timeout) do
      proc = runtime.exec("/bin/bash #{file.path}")

      @out = []
      @err = []

      # Must have a sink for stdout for the proc to exit
      out_thread = read_thread(:stdout, proc.getInputStream, @out)
      err_thread = read_thread(:stderr, proc.getErrorStream, @err)

      out_thread.join
      err_thread.join

      @out = @out.join("\n")
      @err = @err.join("\n")

      # Noticed some cases where the join isn't good enough in the wild.
      proc.waitFor

      @exit = proc.exitValue
    end
  ensure
    file.close
    file.unlink
  end
end