Module: ConsoleUtil

Defined in:
lib/console_util.rb,
lib/console_util/color.rb,
lib/console_util/version.rb

Defined Under Namespace

Classes: Color

Constant Summary collapse

VERSION = 
"0.3.0"

Class Attribute Summary collapse

Class Method Summary collapse

Class Attribute Details

.suppressed_output ⇒ Object (readonly)

Returns the value of attribute suppressed_output.



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# File 'lib/console_util.rb', line 5

def suppressed_output
  @suppressed_output
end

Class Method Details

.grep_stdout(expression) ⇒ Object

Allows you to filter output to the console using grep Ex:

def foo
  puts "Some debugging output here"
  puts "The value of x is y"
  puts "The value of foo is bar"
end

grep_stdout(/value/) { foo }
# => The value of x is y
# => The value of foo is bar
# => nil



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# File 'lib/console_util.rb', line 55

def grep_stdout(expression)
  # First we need to create a ruby "pipe" which is two sets of IO subclasses
  # the first is read only (which represents a fake $stdin) and the second is
  # write only (which represents a fake $stdout).
  placeholder_in, placeholder_out = IO.pipe
  
  # This child process handles the grep'ing.  Its done in a child process so that
  # it can operate in parallel with the main process.
  pid = fork {
    # sync $stdout so we can report any matches asap
    $stdout.sync
    
    # replace $stdout with placeholder_out
    $stdin.reopen(placeholder_in)
    
    # we have to close both placeholder_out and placeholder_in because all instances
    # of an IO stream must be closed in order for it to ever reach EOF.  There's two
    # in this method; one in the child process and one in the main process.
    placeholder_in.close
    placeholder_out.close
    
    # loop continuously until we reach EOF (which happens when all
    # instances of placeholder_out have closed)
    read_buffer = ''
    loop do
      begin
        match     = nil
        next_read = $stdin.readpartial(4096)
        
        read_buffer << next_read
        if line_match = read_buffer.match(/^(.*\n)(.*)$/m)
          match = line_match[1].grep(expression)  # grep complete lines
          read_buffer = line_match[2]           # save remaining partial line for the next iteration
        end
      rescue EOFError
        match = read_buffer.grep(expression)  # grep any remaining partial line at EOF
        break
      end
      
      if match && !match.empty?
        print match
      end
    end
  }
  
  # Save the original stdout out to a variable so we can use it again after this
  # method is done
  original_stdout = $stdout
  
  # Redirect stdout to our pipe
  $stdout = placeholder_out
  
  # sync $stdout so that we can start operating on it as soon as possible
  $stdout.sync
  
  # allow the block to execute and save its return value
  return_value = yield
  
  # Set stdout back to the original so output will flow again
  $stdout = original_stdout
  
  # close the main instances of placeholder_in and placeholder_out
  placeholder_in.close
  placeholder_out.close
  
  # Wait for the child processes to finish
  Process.wait pid
  
  # Because the connection to the database has a tendency to go away when calling this, reconnect here
  # if we're using ActiveRecord
  if defined?(ActiveRecord)
    suppress_stdout { ActiveRecord::Base.verify_active_connections! }
  end
  
  # return the value of the block
  return_value
end

.import_mysql_dump(filename) ⇒ Object

Import a MySQL dump file.

This may work with other databases, but has only been tested with MySQL. 


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# File 'lib/console_util.rb', line 28

def import_mysql_dump(filename)
  sql_dump_file = File.open(Rails.root.join('sql', "#{filename}.sql"))
  while sql_statement = sql_dump_file.gets(";\n") do
    ActiveRecord::Base.connection.execute(sql_statement) unless sql_statement.blank?
  end
end

.load_all_models ⇒ Object

Load all models into the environment



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# File 'lib/console_util.rb', line 36

def load_all_models
  Rails.root.join('app/models').each_entry do |model_file|
    model_match = model_file.to_s.match(/^(.*)\.rb$/)
    model_match[1].classify.constantize if model_match
  end
end

.output_sql_to_console(options = {}) ⇒ Object

Monkey-patch the ActiveRecord connection to output the SQL query before executing it.



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# File 'lib/console_util.rb', line 9

def output_sql_to_console(options = {})
  color = Color::CYAN
  if options[:color]
    raise ArgumentError.new("invalid color option: #{options[:color].inspect}") unless Color.valid_escape_code?(options[:color])
    color = options[:color]
  end

  ActiveRecord::Base.connection.class_eval do
    define_method(:execute) do |sql, *name|
      puts "#{color}#{sql}#{Color::RESET}"
      super
    end
  end
  
  true
end

.suppress_stdout ⇒ Object

Allows you to suppress $stdout but allows you to send certain messages to $stdout Ex:

def foo
  puts "lots of stuff directed to $stdout that I don't want to see."
end

suppress_stdout do |stdout|
  stdout.puts "About to call #foo"
  foo
  stdout.puts "Called foo"
end
# => About to call #foo
# => Called foo
# => <# The result of #foo >



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# File 'lib/console_util.rb', line 147

def suppress_stdout
  original_stdout = $stdout
  $stdout = output_buffer = StringIO.new
  begin
    return_value = yield(original_stdout)
  ensure
    $stdout = original_stdout
    @suppressed_output ||= ""
    @suppressed_output << output_buffer.string
  end
  return_value
end