Module: Fourflusher::Executable

Included in:
SimControl
Defined in:
lib/fourflusher/executable.rb

Overview

Module which provides support for running executables.

In a class it can be used as:

extend Executable
executable :git

This will create two methods git and git! both accept a command but the later will raise on non successful executions. The methods return the output of the command.

Defined Under Namespace

Classes: Indenter

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.capture_command(executable, command, capture: :merge) ⇒ (String, Process::Status)

Runs the given command, capturing the desired output.

Parameters:

  • bin (String) —

    The binary to use.

  • command (Array<#to_s>) —

    The command to send to the binary.

  • capture (Symbol) (defaults to: :merge) —

    Whether it should raise if the command fails.

Returns:

  • ((String, Process::Status)) —

    The desired captured output from the command, and the status from running the command.

Raises:

  • If the executable could not be located.



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# File 'lib/fourflusher/executable.rb', line 145

def self.capture_command(executable, command, capture: :merge)
  bin = which(executable)
  fail Fourflusher::Informative, "Unable to locate the executable `#{executable}`" unless bin

  require 'open3'
  command = command.map(&:to_s)
  case capture
  when :merge then Open3.capture2e(bin, *command)
  when :both then Open3.capture3(bin, *command)
  when :out then Open3.capture2(bin, *command)
  when :err then Open3.capture3(bin, *command).drop(1)
  when :none then Open3.capture2(bin, *command).last
  end
end

.execute_command(executable, command, raise_on_failure = true) ⇒ String

Executes the given command displaying it if in verbose mode.

Parameters:

  • bin (String) —

    The binary to use.

  • command (Array<#to_s>) —

    The command to send to the binary.

  • raise_on_failure (Bool) (defaults to: true) —

    Whether it should raise if the command fails.

Returns:

  • (String) —

    the output of the command (STDOUT and STDERR).

Raises:

  • If the executable could not be located.

  • If the command fails and the raise_on_failure is set to true.



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# File 'lib/fourflusher/executable.rb', line 79

def self.execute_command(executable, command, raise_on_failure = true)
  bin = which(executable)
  fail Fourflusher::Informative, "Unable to locate the executable `#{executable}`" unless bin

  command = command.map(&:to_s)
  full_command = "#{bin} #{command.join(' ')}"

  if Config.instance.verbose?
    UI.message("$ #{full_command}")
    stdout = Indenter.new(STDOUT)
    stderr = Indenter.new(STDERR)
  else
    stdout = Indenter.new
    stderr = Indenter.new
  end

  status = popen3(bin, command, stdout, stderr)
  stdout = stdout.join
  stderr = stderr.join
  output = stdout + stderr
  unless status.success?
    if raise_on_failure
      fail Fourflusher::Informative, "#{full_command}\n\n#{output}"
    else
      UI.message("[!] Failed: #{full_command}".red)
    end
  end

  output
end

.popen3(bin, command, stdout, stderr) ⇒ Object 



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# File 'lib/fourflusher/executable.rb', line 162

def self.popen3(bin, command, stdout, stderr)
  require 'open3'
  Open3.popen3(bin, *command) do |i, o, e, t|
    reader(o, stdout)
    reader(e, stderr)
    i.close

    status = t.value

    o.flush
    e.flush
    sleep(0.01)

    status
  end
end

.reader(input, output) ⇒ Object 



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# File 'lib/fourflusher/executable.rb', line 179

def self.reader(input, output)
  Thread.new do
    buf = ''
    begin
      loop do
        buf << input.readpartial(4096)
        loop do
          string, separator, buf = buf.partition(/[\r\n]/)
          if separator.empty?
            buf = string
            break
          end
          output << (string << separator)
        end
      end
    rescue EOFError
      output << (buf << $INPUT_RECORD_SEPARATOR) unless buf.empty?
    end
  end
end

.which(program) ⇒ String, Nil

Returns the absolute path to the binary with the given name on the current PATH, or nil if none is found.

Parameters:

  • program (String) —

    The name of the program being searched for.

Returns:

  • (String, Nil) —

    The absolute path to the given program, or nil if it wasn’t found in the current PATH.



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# File 'lib/fourflusher/executable.rb', line 119

def self.which(program)
  program = program.to_s
  ENV['PATH'].split(File::PATH_SEPARATOR).each do |path|
    bin = File.expand_path(program, path)
    return bin if File.file?(bin) && File.executable?(bin)
  end
  nil
end

Instance Method Details

#executable(name) ⇒ void

This method returns an undefined value.

Creates the methods for the executable with the given name.

Parameters:

  • name (Symbol) —

    the name of the executable.



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# File 'lib/fourflusher/executable.rb', line 52

def executable(name)
  define_method(name) do |*command|
    Executable.execute_command(name, Array(command).flatten, false)
  end

  define_method(name.to_s + '!') do |*command|
    Executable.execute_command(name, Array(command).flatten, true)
  end
end