# class Dir

- Dir
- Reference
- Object

##
Overview

Objects of class `Dir` are directory streams representing directories in the underlying file system. They provide a variety of ways to list directories and their contents.

The directory used in these examples contains the two regular files (`config.h` and `main.rb`), the parent directory (`..`), and the directory itself (`.`).

See also: `File`.

##
Included Modules

- Enumerable(String)
- Iterable(String)

##
Defined in:

##
Constructors

- .new(path)

  Returns a new directory object for the named directory.

- .open(path) : self

  Alias for `.new(path)`

##
Class Method Summary

- .[](*patterns) : Array(String)

  Returns an array of all files that match against any of patterns.

- .[](patterns : Enumerable(String)) : Array(String)

  Returns an array of all files that match against any of patterns.

- .cd(path)

  Changes the current working directory of the process to the given string.

- .cd(path, &)

  Changes the current working directory of the process to the given string and invokes the block, restoring the original working directory when the block exits.

- .children(dirname) : Array(String)

  See `#children`.

- .current : String

  Returns the current working directory.

- .each(dirname, &)

  See `#each`.

- .each_child(dirname, &)

  See `#each_child`.

- .empty?(path) : Bool

  Returns `true` if the directory at path is empty, otherwise returns `false`.

- .entries(dirname) : Array(String)

  See `#entries`.

- .exists?(path) : Bool

  Returns `true` if the given path exists and is a directory

- .glob(patterns : Enumerable(String), match_hidden = false, &block : String -> _)

  Yields all files that match against any of patterns.

- .glob(*patterns, match_hidden = false) : Array(String)

  Returns an array of all files that match against any of patterns.

- .glob(patterns : Enumerable(String), match_hidden = false) : Array(String)

  Returns an array of all files that match against any of patterns.

- .glob(*patterns, match_hidden = false, &block : String -> _)

  Yields all files that match against any of patterns.

- .mkdir(path, mode = 511)

  Creates a new directory at the given path.

- .mkdir_p(path, mode = 511)

  Creates a new directory at the given path, including any non-existing intermediate directories.

- .open(path, &)

  Opens a directory and yields it, closing it at the end of the block.

- .rmdir(path)

  Removes the directory at the given path.

- .tempdir : String

  Returns the tmp dir used for tempfile.

##
Instance Method Summary

- #children : Array(String)

  Returns an array containing all of the filenames except for `.` and `..` in the given directory.

- #close

  Closes the directory stream.

- #each(&) : Nil

  Calls the block once for each entry in this directory, passing the filename of each entry as a parameter to the block.

- #each

  Must return an `Iterator` over the elements in this collection.

- #each_child(&) : Nil

  Calls the block once for each entry except for `.` and `..` in this directory, passing the filename of each entry as a parameter to the block.

- #each_child
- #entries : Array(String)

  Returns an array containing all of the filenames in the given directory.

- #inspect(io : IO) : Nil

  Appends a String representation of this object which includes its class name, its object address and the values of all instance variables.

- #path : String
- #pretty_print(pp)
- #read

  Reads the next entry from dir and returns it as a string.

- #rewind

  Repositions this directory to the first entry.

- #to_s(io : IO) : Nil

  Appends a short String representation of this object which includes its class name and its object address.

### Instance methods inherited from module `Iterable(String)`

chunk(reuse = false, &block : T -> U) forall U chunk, chunk_while(reuse : Bool | Array(T) = false, &block : T, T -> B) forall B chunk_while, cycle(n)
cycle cycle, each each, each_cons(count : Int, reuse = false) each_cons, each_slice(count : Int, reuse = false) each_slice, each_with_index(offset = 0) each_with_index, each_with_object(obj) each_with_object, slice_after(reuse : Bool | Array(T) = false, &block : T -> B) forall B
slice_after(pattern, reuse : Bool | Array(T) = false) slice_after, slice_before(reuse : Bool | Array(T) = false, &block : T -> B) forall B
slice_before(pattern, reuse : Bool | Array(T) = false) slice_before, slice_when(reuse : Bool | Array(T) = false, &block : T, T -> B) forall B slice_when

### Instance methods inherited from module `Enumerable(String)`

all?(&)
all?(pattern)
all? all?, any?(&)
any?(pattern)
any? any?, chunks(&block : T -> U) forall U chunks, compact_map(&) compact_map, count(&)
count(item) count, cycle(n, &)
cycle(&) cycle, each(&block : T -> _) each, each_cons(count : Int, reuse = false, &) each_cons, each_cons_pair(& : T, T -> _) : Nil each_cons_pair, each_slice(count : Int, reuse = false, &) each_slice, each_with_index(offset = 0, &) each_with_index, each_with_object(obj, &) each_with_object, find(if_none = nil, &) find, first(count : Int)
first first, first? first?, flat_map(&block : T -> Array(U) | Iterator(U) | U) forall U flat_map, grep(pattern) grep, group_by(&block : T -> U) forall U group_by, in_groups_of(size : Int, filled_up_with : U = nil) forall U
in_groups_of(size : Int, filled_up_with : U = nil, reuse = false, &) forall U in_groups_of, includes?(obj) includes?, index(&)
index(obj) index, index_by(&block : T -> U) forall U index_by, join(separator = "", &)
join(separator, io, &)
join(separator, io)
join(separator = "") join, map(&block : T -> U) forall U map, map_with_index(offset = 0, &block : T, Int32 -> U) forall U map_with_index, max max, max? max?, max_by(&block : T -> U) forall U max_by, max_by?(&block : T -> U) forall U max_by?, max_of(&block : T -> U) forall U max_of, max_of?(&block : T -> U) forall U max_of?, min min, min? min?, min_by(&block : T -> U) forall U min_by, min_by?(&block : T -> U) forall U min_by?, min_of(&block : T -> U) forall U min_of, min_of?(&block : T -> U) forall U min_of?, minmax minmax, minmax? minmax?, minmax_by(&block : T -> U) forall U minmax_by, minmax_by?(&block : T -> U) forall U minmax_by?, minmax_of(&block : T -> U) forall U minmax_of, minmax_of?(&block : T -> U) forall U minmax_of?, none?
none?(pattern)
none?(&) none?, one?(&)
one?(pattern)
one? one?, partition(&) partition, product(&)
product(initial : Number, &)
product
product(initial : Number) product, reduce(memo, &)
reduce(&) reduce, reduce?(&) reduce?, reject(&block : T -> )
reject(type : U.class) forall U
reject(pattern) reject, select(pattern)
select(type : U.class) forall U
select(&block : T -> ) select, size size, skip(count : Int) skip, skip_while(&) skip_while, sum(initial)
sum
sum(initial, &)
sum(&) sum, take_while(&) take_while, tally : Hash(T, Int32) tally, to_a to_a, to_h
to_h(&block : T -> Tuple(K, V)) forall K, V to_h, to_set to_set, zip(*others : Indexable | Iterable | Iterator, &)
zip(*others : Indexable | Iterable | Iterator) zip, zip?(*others : Indexable | Iterable | Iterator, &)
zip?(*others : Indexable | Iterable | Iterator) zip?

### Instance methods inherited from class `Reference`

==(other : self)
==(other : JSON::Any)
==(other : YAML::Any)
==(other) ==, dup dup, hash(hasher) hash, inspect(io : IO) : Nil inspect, object_id : UInt64 object_id, pretty_print(pp) : Nil pretty_print, same?(other : Reference)
same?(other : Nil) same?, to_s(io : IO) : Nil to_s

### Constructor methods inherited from class `Reference`

new new

### Instance methods inherited from class `Object`

!=(other) !=, !~(other) !~, ==(other) ==, ===(other : JSON::Any)
===(other : YAML::Any)
===(other) ===, =~(other) =~, __crystal_pseudo_! : Bool __crystal_pseudo_!, __crystal_pseudo_as(type : Class) __crystal_pseudo_as, __crystal_pseudo_as?(type : Class) __crystal_pseudo_as?, __crystal_pseudo_is_a?(type : Class) : Bool __crystal_pseudo_is_a?, __crystal_pseudo_nil? : Bool __crystal_pseudo_nil?, __crystal_pseudo_responds_to?(name : Symbol) : Bool __crystal_pseudo_responds_to?, class class, dup dup, hash(hasher)
hash hash, inspect : String
inspect(io : IO) : Nil inspect, itself itself, not_nil! not_nil!, pretty_inspect(width = 79, newline = "\n", indent = 0) : String pretty_inspect, pretty_print(pp : PrettyPrint) : Nil pretty_print, tap(&) tap, to_json(io : IO)
to_json to_json, to_pretty_json(indent : String = " ")
to_pretty_json(io : IO, indent : String = " ") to_pretty_json, to_s : String
to_s(io : IO) : Nil to_s, to_yaml(io : IO)
to_yaml to_yaml, try(&) try, unsafe_as(type : T.class) forall T unsafe_as

### Class methods inherited from class `Object`

from_json(string_or_io, root : String)
from_json(string_or_io) from_json, from_yaml(string_or_io : String | IO) from_yaml

##
Constructor Detail

def self.new(path) #

Returns a new directory object for the named directory.

def self.open(path) : self #

Alias for `.new(path)`

##
Class Method Detail

def self.[](*patterns) : Array(String) #

Returns an array of all files that match against any of patterns.

The pattern syntax is similar to shell filename globbing, see `File.match?` for details.

NOTE Path separator in patterns needs to be always `/`. The returned file names use system-specific path separators.

def self.[](patterns : Enumerable(String)) : Array(String) #

Returns an array of all files that match against any of patterns.

The pattern syntax is similar to shell filename globbing, see `File.match?` for details.

NOTE Path separator in patterns needs to be always `/`. The returned file names use system-specific path separators.

def self.cd(path) #

Changes the current working directory of the process to the given string.

def self.cd(path, &) #

Changes the current working directory of the process to the given string and invokes the block, restoring the original working directory when the block exits.

def self.children(dirname) : Array(String) #

See `#children`.

def self.current : String #

Returns the current working directory.

def self.each(dirname, &) #

See `#each`.

def self.each_child(dirname, &) #

See `#each_child`.

def self.empty?(path) : Bool #

Returns `true` if the directory at path is empty, otherwise returns `false`. Raises `Errno` if the directory at path does not exist.

    Dir.mkdir("bar")
    Dir.empty?("bar") # => true
    File.write("bar/a_file", "The content")
    Dir.empty?("bar") # => false

def self.entries(dirname) : Array(String) #

See `#entries`.

def self.exists?(path) : Bool #

Returns `true` if the given path exists and is a directory

def self.glob(patterns : Enumerable(String), match_hidden = false, &block : String -> _) #

Yields all files that match against any of patterns.

The pattern syntax is similar to shell filename globbing, see `File.match?` for details.

If match_hidden is `true` the pattern will match hidden files and folders.

NOTE Path separator in patterns needs to be always `/`. The returned file names use system-specific path separators.

def self.glob(*patterns, match_hidden = false) : Array(String) #

Returns an array of all files that match against any of patterns.

The pattern syntax is similar to shell filename globbing, see `File.match?` for details.

If match_hidden is `true` the pattern will match hidden files and folders.

NOTE Path separator in patterns needs to be always `/`. The returned file names use system-specific path separators.

def self.glob(patterns : Enumerable(String), match_hidden = false) : Array(String) #

Returns an array of all files that match against any of patterns.

The pattern syntax is similar to shell filename globbing, see `File.match?` for details.

If match_hidden is `true` the pattern will match hidden files and folders.

NOTE Path separator in patterns needs to be always `/`. The returned file names use system-specific path separators.

def self.glob(*patterns, match_hidden = false, &block : String -> _) #

Yields all files that match against any of patterns.

The pattern syntax is similar to shell filename globbing, see `File.match?` for details.

If match_hidden is `true` the pattern will match hidden files and folders.

NOTE Path separator in patterns needs to be always `/`. The returned file names use system-specific path separators.

def self.mkdir(path, mode = 511) #

Creates a new directory at the given path. The linux-style permission mode can be specified, with a default of 777 (0o777).

NOTE mode is ignored on windows.

def self.mkdir_p(path, mode = 511) #

Creates a new directory at the given path, including any non-existing intermediate directories. The linux-style permission mode can be specified, with a default of 777 (0o777).

def self.open(path, &) #

Opens a directory and yields it, closing it at the end of the block. Returns the value of the block.

def self.rmdir(path) #

Removes the directory at the given path.

def self.tempdir : String #

Returns the tmp dir used for tempfile.

    Dir.tempdir # => "/tmp"

##
Instance Method Detail

def children : Array(String) #

Returns an array containing all of the filenames except for `.` and `..` in the given directory.

def close #

Closes the directory stream.

def each(&) : Nil #

Calls the block once for each entry in this directory, passing the filename of each entry as a parameter to the block.

    Dir.mkdir("testdir")
    File.write("testdir/config.h", "")

    d = Dir.new("testdir")
    d.each { |x| puts "Got #{x}" }

produces:

    Got .
    Got ..
    Got config.h

def each #
Description copied from module Iterable(String)

Must return an `Iterator` over the elements in this collection.

def each_child(&) : Nil #

Calls the block once for each entry except for `.` and `..` in this directory, passing the filename of each entry as a parameter to the block.

    Dir.mkdir("testdir")
    File.write("testdir/config.h", "")

    d = Dir.new("testdir")
    d.each_child { |x| puts "Got #{x}" }

produces:

    Got config.h

def each_child #
def entries : Array(String) #

Returns an array containing all of the filenames in the given directory.

def inspect(io : IO) : Nil #
Description copied from class Reference

Appends a String representation of this object which includes its class name, its object address and the values of all instance variables.

    class Person
      def initialize(@name : String, @age : Int32)
      end
    end

    Person.new("John", 32).inspect # => #<Person:0x10fd31f20 @name="John", @age=32>

def path : String #
def pretty_print(pp) #
def read #

Reads the next entry from dir and returns it as a string. Returns `nil` at the end of the stream.

    d = Dir.new("testdir")
    array = [] of String
    while file = d.read
      array << file
    end
    array.sort # => [".", "..", "config.h"]

def rewind #

Repositions this directory to the first entry.

def to_s(io : IO) : Nil #
Description copied from class Reference

Appends a short String representation of this object which includes its class name and its object address.

    class Person
      def initialize(@name : String, @age : Int32)
      end
    end

    Person.new("John", 32).to_s # => #<Person:0x10a199f20>