Class

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. See also File.

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


Equivalent to calling Dir.glob([string,...], 0).

Changes the current working directory of the process to the given string. When called without an argument, changes the directory to the value of the environment variable HOME, or LOGDIR. SystemCallError (probably Errno::ENOENT) if the target directory does not exist.

If a block is given, it is passed the name of the new current directory, and the block is executed with that as the current directory. The original working directory is restored when the block exits. The return value of chdir is the value of the block. chdir blocks can be nested, but in a multi-threaded program an error will be raised if a thread attempts to open a chdir block while another thread has one open.

Dir.chdir("/var/spool/mail")
puts Dir.pwd
Dir.chdir("/tmp") do
  puts Dir.pwd
  Dir.chdir("/usr") do
    puts Dir.pwd
  end
  puts Dir.pwd
end
puts Dir.pwd

produces:

/var/spool/mail
/tmp
/usr
/tmp
/var/spool/mail

Returns an array containing all of the filenames except for “.” and “..” in the given directory. Will raise a SystemCallError if the named directory doesn't exist.

The optional encoding keyword argument specifies the encoding of the directory. If not specified, the filesystem encoding is used.

Dir.children("testdir")   #=> ["config.h", "main.rb"]

Changes this process's idea of the file system root. Only a privileged process may make this call. Not available on all platforms. On Unix systems, see chroot(2) for more information.

Closes the directory stream. Calling this method on closed Dir object is ignored since Ruby 2.3.

d = Dir.new("testdir")
d.close   #=> nil

Deletes the named directory. Raises a subclass of SystemCallError if the directory isn't empty.

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

If no block is given, an enumerator is returned instead.

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

produces:

Got .
Got ..
Got config.h
Got main.rb

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

If no block is given, an enumerator is returned instead.

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

produces:

Got config.h
Got main.rb

Returns true if the named file is an empty directory, false if it is not a directory or non-empty.

Returns an array containing all of the filenames in the given directory. Will raise a SystemCallError if the named directory doesn't exist.

The optional encoding keyword argument specifies the encoding of the directory. If not specified, the filesystem encoding is used.

Dir.entries("testdir")   #=> [".", "..", "config.h", "main.rb"]

Returns true if the named file is a directory, false otherwise.

Deprecated method. Don't use.

Returns the file descriptor used in dir.

d = Dir.new("..")
d.fileno   #=> 8

This method uses dirfd() function defined by POSIX 2008. NotImplementedError is raised on other platforms, such as Windows, which doesn't provide the function.

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

If no block is given, an enumerator is returned instead.

Dir.foreach("testdir") {|x| puts "Got #{x}" }

produces:

Got .
Got ..
Got config.h
Got main.rb

Returns the path to the current working directory of this process as a string.

Dir.chdir("/tmp")   #=> 0
Dir.getwd           #=> "/tmp"
Dir.pwd             #=> "/tmp"

Expands pattern, which is a pattern string or an Array of pattern strings, and returns an array containing the matching filenames. If a block is given, calls the block once for each matching filename, passing the filename as a parameter to the block.

The optional base keyword argument specifies the base directory for interpreting relative pathnames instead of the current working directory. As the results are not prefixed with the base directory name in this case, you will need to prepend the base directory name if you want real paths.

Note that the pattern is not a regexp, it's closer to a shell glob. See File::fnmatch for the meaning of the flags parameter. Case sensitivity depends on your system (File::FNM_CASEFOLD is ignored), as does the order in which the results are returned.

*

Matches any file. Can be restricted by other values in the glob. Equivalent to / .* /mx in regexp.

*

Matches all files

c*

Matches all files beginning with c

*c

Matches all files ending with c

*c*

Match all files that have c in them (including at the beginning or end).

Note, this will not match Unix-like hidden files (dotfiles). In order to include those in the match results, you must use the File::FNM_DOTMATCH flag or something like "{*,.*}".

**

Matches directories recursively.

?

Matches any one character. Equivalent to /.{1}/ in regexp.

[set]

Matches any one character in set. Behaves exactly like character sets in Regexp, including set negation ([^a-z]).

{p,q}

Matches either literal p or literal q. Equivalent to pattern alternation in regexp.

Matching literals may be more than one character in length. More than two literals may be specified.

\

Escapes the next metacharacter.

Note that this means you cannot use backslash on windows as part of a glob, i.e. Dir["c:\foo*"] will not work, use Dir["c:/foo*"] instead.

Examples:

Dir["config.?"]                     #=> ["config.h"]
Dir.glob("config.?")                #=> ["config.h"]
Dir.glob("*.[a-z][a-z]")            #=> ["main.rb"]
Dir.glob("*.[^r]*")                 #=> ["config.h"]
Dir.glob("*.{rb,h}")                #=> ["main.rb", "config.h"]
Dir.glob("*")                       #=> ["config.h", "main.rb"]
Dir.glob("*", File::FNM_DOTMATCH)   #=> [".", "..", "config.h", "main.rb"]
Dir.glob(["*.rb", "*.h"])           #=> ["main.rb", "config.h"]

rbfiles = File.join("**", "*.rb")
Dir.glob(rbfiles)                   #=> ["main.rb",
                                    #    "lib/song.rb",
                                    #    "lib/song/karaoke.rb"]

Dir.glob(rbfiles, base: "lib")      #=> ["song.rb",
                                    #    "song/karaoke.rb"]

libdirs = File.join("**", "lib")
Dir.glob(libdirs)                   #=> ["lib"]

librbfiles = File.join("**", "lib", "**", "*.rb")
Dir.glob(librbfiles)                #=> ["lib/song.rb",
                                    #    "lib/song/karaoke.rb"]

librbfiles = File.join("**", "lib", "*.rb")
Dir.glob(librbfiles)                #=> ["lib/song.rb"]

Returns the home directory of the current user or the named user if given.

Return a string describing this Dir object.

Makes a new directory named by string, with permissions specified by the optional parameter anInteger. The permissions may be modified by the value of File::umask, and are ignored on NT. Raises a SystemCallError if the directory cannot be created. See also the discussion of permissions in the class documentation for File.

Dir.mkdir(File.join(Dir.home, ".foo"), 0700) #=> 0

mktmpdir

::

Dir.mktmpdir creates a temporary 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") { ... }
}

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") { ... }
ensure
  # remove the directory.
  FileUtils.remove_entry dir
end

Returns a new directory object for the named directory.

The optional encoding keyword argument specifies the encoding of the directory. If not specified, the filesystem encoding is used.

The optional encoding keyword argument specifies the encoding of the directory. If not specified, the filesystem encoding is used.

With no block, open is a synonym for Dir::new. If a block is present, it is passed aDir as a parameter. The directory is closed at the end of the block, and Dir::open returns the value of the block.

Returns the path parameter passed to dir's constructor.

d = Dir.new("..")
d.path   #=> ".."

Returns the current position in dir. See also Dir#seek.

d = Dir.new("testdir")
d.tell   #=> 0
d.read   #=> "."
d.tell   #=> 12

Synonym for Dir#seek, but returns the position parameter.

d = Dir.new("testdir")   #=> #<Dir:0x401b3c40>
d.read                   #=> "."
i = d.pos                #=> 12
d.read                   #=> ".."
d.pos = i                #=> 12
d.read                   #=> ".."

Returns the path to the current working directory of this process as a string.

Dir.chdir("/tmp")   #=> 0
Dir.getwd           #=> "/tmp"
Dir.pwd             #=> "/tmp"

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

d = Dir.new("testdir")
d.read   #=> "."
d.read   #=> ".."
d.read   #=> "config.h"

Repositions dir to the first entry.

d = Dir.new("testdir")
d.read     #=> "."
d.rewind   #=> #<Dir:0x401b3fb0>
d.read     #=> "."

Deletes the named directory. Raises a subclass of SystemCallError if the directory isn't empty.

Seeks to a particular location in dir. integer must be a value returned by Dir#tell.

d = Dir.new("testdir")   #=> #<Dir:0x401b3c40>
d.read                   #=> "."
i = d.tell               #=> 12
d.read                   #=> ".."
d.seek(i)                #=> #<Dir:0x401b3c40>
d.read                   #=> ".."

Returns the current position in dir. See also Dir#seek.

d = Dir.new("testdir")
d.tell   #=> 0
d.read   #=> "."
d.tell   #=> 12

tmpdir

::

Returns the operating system's temporary file path.

Returns the path parameter passed to dir's constructor.

d = Dir.new("..")
d.path   #=> ".."

Deletes the named directory. Raises a subclass of SystemCallError if the directory isn't empty.