Method: Tempfile#initialize

Defined in:
lib/tempfile.rb

#initialize(basename = "", tmpdir = nil, mode: 0, **options) ⇒ Tempfile

Creates a file in the underlying file system; returns a new Tempfile object based on that file.

If possible, consider instead using Tempfile.create, which:

  • Avoids the performance cost of delegation, incurred when Tempfile.new calls its superclass DelegateClass(File).

  • Does not rely on a finalizer to close and unlink the file, which can be unreliable.

Creates and returns file whose:

  • Class is Tempfile (not File, as in Tempfile.create).

  • Directory is the system temporary directory (system-dependent).

  • Generated filename is unique in that directory.

  • Permissions are 0600; see File Permissions.

  • Mode is 'w+' (read/write mode, positioned at the end).

The underlying file is removed when the Tempfile object dies and is reclaimed by the garbage collector.

Example:

f = Tempfile.new # => #<Tempfile:/tmp/20220505-17839-1s0kt30>
f.class               # => Tempfile
f.path                # => "/tmp/20220505-17839-1s0kt30"
f.stat.mode.to_s(8)   # => "100600"
File.exist?(f.path)   # => true
File.unlink(f.path)   #
File.exist?(f.path)   # => false

Argument basename, if given, may be one of:

  • A string: the generated filename begins with basename:

    Tempfile.new('foo') # => #<Tempfile:/tmp/foo20220505-17839-1whk2f>

  • An array of two strings [prefix, suffix]: the generated filename begins with prefix and ends with suffix:

    Tempfile.new(%w/foo .jpg/) # => #<Tempfile:/tmp/foo20220505-17839-58xtfi.jpg>

With arguments basename and tmpdir, the file is created in directory tmpdir:

Tempfile.new('foo', '.') # => #<Tempfile:./foo20220505-17839-xfstr8>

Keyword arguments mode and options are passed directly to method File.open:

  • The value given with mode must be an integer, and may be expressed as the logical OR of constants defined in File::Constants.

  • For options, see Open Options.

Related: Tempfile.create.



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# File 'lib/tempfile.rb', line 219

def initialize(basename="", tmpdir=nil, mode: 0, **options)
  warn "Tempfile.new doesn't call the given block.", uplevel: 1 if block_given?

  @unlinked = false
  @mode = mode|File::RDWR|File::CREAT|File::EXCL
  tmpfile = nil
  ::Dir::Tmpname.create(basename, tmpdir, **options) do |tmpname, n, opts|
    opts[:perm] = 0600
    tmpfile = File.open(tmpname, @mode, **opts)
    @opts = opts.freeze
  end

  super(tmpfile)

  @finalizer_manager = FinalizerManager.new(__getobj__.path)
  @finalizer_manager.register(self, __getobj__)
end