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 (.).
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
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.
Returns an array containing all of the filenames in the given directory. Will raise a SystemCallError if the named directory doesn’t exist.
Dir.entries("testdir") #=> [".", "..", "config.h", "main.rb"]
Calls the block once for each entry in the named directory, passing the filename of each entry as a parameter to the block.
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"
Returns the filenames found by expanding the pattern given in string, either as an array or as parameters to the block. Note that this pattern is not a regexp (it’s closer to a shell glob). See File::fnmatch for details of file name matching and the meaning of the flags parameter.
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"]
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.
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 to the current working directory of this process as a string.
Dir.chdir("/tmp") #=> 0
Dir.getwd #=> "/tmp"
Closes the directory stream. Any further attempts to access dir will raise an IOError.
d = Dir.new("testdir")
d.close #=> nil
Calls the block once for each entry in this directory, passing the filename of each entry as a parameter to the block.
d = Dir.new("testdir")
d.each {|x| puts "Got #{x}" }
produces:
Got . Got .. Got config.h Got main.rb
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 #=> ".."
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 #=> "."
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