diff options
Diffstat (limited to 'lib/tmpdir.rb')
| -rw-r--r-- | lib/tmpdir.rb | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/lib/tmpdir.rb b/lib/tmpdir.rb new file mode 100644 index 0000000000..f78fd721b7 --- /dev/null +++ b/lib/tmpdir.rb @@ -0,0 +1,189 @@ +# frozen_string_literal: true +# +# tmpdir - retrieve temporary directory path +# +# $Id$ +# + +require 'fileutils' +begin + require 'etc.so' +rescue LoadError # rescue LoadError for miniruby +end + +class Dir + + # Class variables are inaccessible from non-main Ractor. + # And instance variables too, in Ruby 3.0. + + ## + # Returns the operating system's temporary file path. + # + # require 'tmpdir' + # Dir.tmpdir # => "/tmp" + + def self.tmpdir + Tmpname::TMPDIR_CANDIDATES.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 + + # 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, <i>prefix_suffix</i>. + # - 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 <i>tmpdir</i> 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 + # + def self.mktmpdir(prefix_suffix=nil, *rest, **options, &block) + base = nil + path = Tmpname.create(prefix_suffix || "d", *rest, **options) {|path, _, _, d| + base = d + mkdir(path, 0700) + } + if block + 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 + + # Temporary name generator + module Tmpname # :nodoc: + module_function + + # System-wide temporary directory path + systmpdir = (defined?(Etc.systmpdir) ? Etc.systmpdir.freeze : '/tmp') + + # Temporary directory candidates consisting of environment variable + # names or description and path pairs. + TMPDIR_CANDIDATES = [ + 'TMPDIR', 'TMP', 'TEMP', + ['system temporary path', systmpdir], + %w[/tmp /tmp], + %w[. .], + ].each(&:freeze).freeze + + def tmpdir + Dir.tmpdir + end + + # Unusable characters as path name + UNUSABLE_CHARS = "^,-.0-9A-Z_a-z~" + + # Dedicated random number generator + RANDOM = Object.new + class << RANDOM # :nodoc: + # Maximum random number + MAX = 36**6 # < 0x100000000 + + # Returns new random string upto 6 bytes + def next + (::Random.urandom(4).unpack1("L")%MAX).to_s(36) + end + end + RANDOM.freeze + private_constant :RANDOM + + # Generates and yields random names to create a temporary name + def create(basename, tmpdir=nil, max_try: nil, **opts) + if tmpdir + origdir = tmpdir = File.path(tmpdir) + raise ArgumentError, "empty parent path" if tmpdir.empty? + else + tmpdir = tmpdir() + end + n = nil + prefix, suffix = basename + prefix = (String.try_convert(prefix) or + raise ArgumentError, "unexpected prefix: #{prefix.inspect}") + prefix = prefix.delete(UNUSABLE_CHARS) + suffix &&= (String.try_convert(suffix) or + raise ArgumentError, "unexpected suffix: #{suffix.inspect}") + suffix &&= suffix.delete(UNUSABLE_CHARS) + begin + t = Time.now.strftime("%Y%m%d") + path = "#{prefix}#{t}-#{$$}-#{RANDOM.next}"\ + "#{n ? %[-#{n}] : ''}#{suffix||''}" + path = File.join(tmpdir, path) + yield(path, n, opts, origdir) + rescue Errno::EEXIST + n ||= 0 + n += 1 + retry if !max_try or n < max_try + raise "cannot generate temporary name using '#{basename}' under '#{tmpdir}'" + end + path + end + end +end |