class Headless::CliUtil

Public Class Methods

application_exists?(app) click to toggle source
# File lib/headless/cli_util.rb, line 3
def self.application_exists?(app)
  !!path_to(app)
end
ensure_application_exists!(app, error_message) click to toggle source
# File lib/headless/cli_util.rb, line 7
def self.ensure_application_exists!(app, error_message)
  if !self.application_exists?(app)
    raise Headless::Exception.new(error_message)
  end
end
fork_process(command, pid_filename, log_filename='/dev/null') click to toggle source
# File lib/headless/cli_util.rb, line 42
def self.fork_process(command, pid_filename, log_filename='/dev/null')
  pid = Process.spawn(command, err: log_filename)
  File.open pid_filename, 'w' do |f|
    f.puts pid
  end
end
kill_process(pid_filename, options={}) click to toggle source
# File lib/headless/cli_util.rb, line 49
def self.kill_process(pid_filename, options={})
  if pid = read_pid(pid_filename)
    begin
      Process.kill 'TERM', pid
      Process.wait pid if options[:wait]
    rescue Errno::ESRCH
      # no such process; assume it's already killed
    rescue Errno::ECHILD
      # Process.wait tried to wait on a dead process
    end
  end

  unless options[:preserve_pid_file]
    begin
      FileUtils.rm pid_filename
    rescue Errno::ENOENT
      # pid file already removed
    end
  end
end
path_to(app) click to toggle source

Credit: stackoverflow.com/a/5471032/6678

# File lib/headless/cli_util.rb, line 14
def self.path_to(app)
  exts = ENV['PATHEXT'] ? ENV['PATHEXT'].split(';') : ['']
  ENV['PATH'].split(File::PATH_SEPARATOR).each do |path|
    exts.each { |ext|
      exe = File.join(path, "#{app}#{ext}")
      return exe if File.executable?(exe) && !File.directory?(exe)
    }
  end
  return nil
end
process_mine?(pid) click to toggle source
# File lib/headless/cli_util.rb, line 25
def self.process_mine?(pid)
  Process.kill(0, pid) && true
rescue Errno::EPERM, Errno::ESRCH
  false
end
process_running?(pid) click to toggle source
# File lib/headless/cli_util.rb, line 31
def self.process_running?(pid)
  Process.getpgid(pid) && true
rescue Errno::ESRCH
  false
end
read_pid(pid_filename) click to toggle source
# File lib/headless/cli_util.rb, line 37
def self.read_pid(pid_filename)
  pid = (File.read(pid_filename) rescue "").strip
  pid.empty? ? nil : pid.to_i
end