Module: MiscHacks

Defined in:
lib/mischacks.rb,
lib/mischacks.rb,
lib/mischacks.rb,
lib/mischacks/random.rb,
lib/mischacks/password.rb

Defined Under Namespace

Modules: ExceptionMixin, IOMixin Classes: ChildError, Password, Random

Constant Summary collapse

VERSION = 
File.read(File.dirname(__FILE__)+'/../VERSION').chomp
RANDOM = 
Random.instance

Class Method Summary collapse

Class Method Details

.catching_exit(final_proc, fallthrough_status) ⇒ Object 



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

def self.catching_exit final_proc, fallthrough_status
  status = fallthrough_status

  begin
    yield
  rescue SystemExit => e
    status = e.status
  rescue Exception => e
    warn e.to_formatted_string
  ensure
    final_proc.call status
  end

  status
end

.do_and_exit(status = 1, &block) ⇒ Object 



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# File 'lib/mischacks.rb', line 71

def self.do_and_exit status=1, &block
  catching_exit method(:exit), status, &block
end

.do_and_exit!(status = 1, &block) ⇒ Object 



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# File 'lib/mischacks.rb', line 75

def self.do_and_exit! status=1, &block
  catching_exit method(:exit!), status, &block
end

.fork_and_check ⇒ Object 



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# File 'lib/mischacks.rb', line 44

def self.fork_and_check
  fork do
    yield
  end.tap do |pid|
    _, status = Process.wait2 pid
    raise ChildError, status.exitstatus if status.exitstatus != 0
  end

  nil
end

.overwrite(path, mode = nil) ⇒ Object 



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# File 'lib/mischacks.rb', line 79

def self.overwrite path, mode=nil
  begin
    stat = File.stat path

    raise ArgumentError, "Not a file: #{path}",   caller unless stat.file?
    raise ArgumentError, "Not writable: #{path}", caller unless stat.writable?

    mode ||= stat.mode & 0777
  rescue Errno::ENOENT
    stat = nil
  end

  temppath, io = try_n_times do
    t  = tempname_for path
    io = File.open t, File::RDWR|File::CREAT|File::EXCL
    [t, io]
  end

  begin
    ret = yield io

    io.best_datasync

    File.chmod mode, temppath if mode

    File.rename temppath, path

  rescue
    File.unlink temppath
    raise

  ensure
    io.close
  end

  ret
end

.sh(cmd, *args) ⇒ Object 



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# File 'lib/mischacks.rb', line 31

def self.sh cmd, *args
  env = if args.last.is_a? Hash then args.pop else {} end

  fork_and_check do
    do_and_exit! do
      env.each_pair do |k, v| ENV[k.to_s] = v.to_s end
      exec *(%W{sh -e -c #{cmd} sh} + args.map(&:to_s))
    end
  end

  nil
end

.tempname_for(path) ⇒ Object 



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# File 'lib/mischacks.rb', line 117

def self.tempname_for path
  dirname  = File.dirname  path
  basename = File.basename path

  '%s/.%s.%s%s%s' % [
    dirname,
    basename,
    Time.now.to_i.to_s(36),
    $$.to_s(36),
    rand(1<<32).to_s(36)
  ]
end

.try_n_times(n = 10) ⇒ Object 



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# File 'lib/mischacks.rb', line 130

def self.try_n_times n=10
  i = 0
  begin
    yield
  rescue
    i += 1
    retry if i < n
    raise
  end
end