class Dir

Dir.mktmpdir creates a temporary directory.

require 'tmpdir'
Dir.mktmpdir {|dir|
  # use the directory
}

The directory is created with 0700 permission. Application should not change the permission to make the temporary directory accessible from other users.

The prefix and suffix of the name of the directory is specified by the optional first argument, prefix_suffix.

• If it is not specified or nil, “d” is used as the prefix and no suffix is used.

• If it is a string, it is used as the prefix and no suffix is used.

• If it is an array, first element is used as the prefix and second element is used as a suffix.

Dir.mktmpdir {|dir| dir is ".../d..." }
Dir.mktmpdir("foo") {|dir| dir is ".../foo..." }
Dir.mktmpdir(["foo", "bar"]) {|dir| dir is ".../foo...bar" }

The directory is created under Dir.tmpdir or the optional second argument tmpdir if non-nil value is given.

Dir.mktmpdir {|dir| dir is "#{Dir.tmpdir}/d..." }
Dir.mktmpdir(nil, "/var/tmp") {|dir| dir is "/var/tmp/d..." }

If a block is given, it is yielded with the path of the directory. The directory and its contents are removed using FileUtils.remove_entry before Dir.mktmpdir returns. The value of the block is returned.

Dir.mktmpdir {|dir|
  # use the directory...
  open("#{dir}/foo", "w") { something using the file }
}

If a block is not given, The path of the directory is returned. In this case, Dir.mktmpdir doesn’t remove the directory.

dir = Dir.mktmpdir
begin
  # use the directory...
  open("#{dir}/foo", "w") { something using the file }
ensure
  # remove the directory.
  FileUtils.remove_entry dir
end

# File tmpdir.rb, line 101
def self.mktmpdir(prefix_suffix=nil, *rest, **options)
  base = nil
  path = Tmpname.create(prefix_suffix || "d", *rest, **options) {|path, _, _, d|
    base = d
    mkdir(path, 0700)
  }
  if block_given?
    begin
      yield path.dup
    ensure
      unless base
        base = File.dirname(path)
        stat = File.stat(base)
        if stat.world_writable? and !stat.sticky?
          raise ArgumentError, "parent directory is world writable but not sticky: #{base}"
        end
      end
      FileUtils.remove_entry path
    end
  else
    path
  end
end

Returns the operating system’s temporary file path.

require 'tmpdir'
Dir.tmpdir # => "/tmp"

# File tmpdir.rb, line 29
def self.tmpdir
  ['TMPDIR', 'TMP', 'TEMP', ['system temporary path', SYSTMPDIR], ['/tmp']*2, ['.']*2].find do |name, dir|
    unless dir
      next if !(dir = ENV[name] rescue next) or dir.empty?
    end
    dir = File.expand_path(dir)
    stat = File.stat(dir) rescue next
    case
    when !stat.directory?
      warn "#{name} is not a directory: #{dir}"
    when !File.writable?(dir)
      # We call File.writable?, not stat.writable?, because you can't tell if a dir is actually
      # writable just from stat; OS mechanisms other than user/group/world bits can affect this.
      warn "#{name} is not writable: #{dir}"
    when stat.world_writable? && !stat.sticky?
      warn "#{name} is world-writable: #{dir}"
    else
      break dir
    end
  end or raise ArgumentError, "could not find a temporary directory"
end