Object
Pathname represents a pathname which locates a file in a filesystem. The pathname depends on OS: Unix, Windows, etc. Pathname library works with pathnames of local OS. However non-Unix pathnames are supported experimentally.
It does not represent the file itself. A Pathname can be relative or absolute. It's not until you try to reference the file that it even matters whether the file exists or not.
Pathname is immutable. It has no method for destructive update.
The value of this class is to manipulate file path information in a neater way than standard Ruby provides. The examples below demonstrate the difference. All functionality from File, FileTest, and some from Dir and FileUtils is included, in an unsurprising way. It is essentially a facade for all of these, and more.
require 'pathname' p = Pathname.new("/usr/bin/ruby") size = p.size # 27662 isdir = p.directory? # false dir = p.dirname # Pathname:/usr/bin base = p.basename # Pathname:ruby dir, base = p.split # [Pathname:/usr/bin, Pathname:ruby] data = p.read p.open { |f| _ } p.each_line { |line| _ }
p = "/usr/bin/ruby" size = File.size(p) # 27662 isdir = File.directory?(p) # false dir = File.dirname(p) # "/usr/bin" base = File.basename(p) # "ruby" dir, base = File.split(p) # ["/usr/bin", "ruby"] data = File.read(p) File.open(p) { |f| _ } File.foreach(p) { |line| _ }
p1 = Pathname.new("/usr/lib") # Pathname:/usr/lib p2 = p1 + "ruby/1.8" # Pathname:/usr/lib/ruby/1.8 p3 = p1.parent # Pathname:/usr p4 = p2.relative_path_from(p3) # Pathname:lib/ruby/1.8 pwd = Pathname.pwd # Pathname:/home/gavin pwd.absolute? # true p5 = Pathname.new "." # Pathname:. p5 = p5 + "music/../articles" # Pathname:music/../articles p5.cleanpath # Pathname:articles p5.realpath # Pathname:/home/gavin/articles p5.children # [Pathname:/home/gavin/articles/linux, ...]
These methods are effectively manipulating a String, because that's all a path is. Except for mountpoint?, children, and realpath, they don't access the filesystem.
+
These methods are a facade for FileTest:
These methods are a facade for File:
chown(owner, group)
lchown(owner, group)
fnmatch(pattern, *args)
fnmatch?(pattern, *args)
open(*args, &block)
utime(atime, mtime)
These methods are a facade for Dir:
each_entry(&block)
These methods are a facade for IO:
each_line(*args, &block)
These methods are a mixture of Find, FileUtils, and others:
As the above section shows, most of the methods in Pathname are facades.  The documentation for these
methods generally just says, for instance, “See FileTest.writable?”, as you
should be familiar with the original method anyway, and its documentation
(e.g. through ri) will contain more information.  In some
cases, a brief description will follow.
See Dir.getwd.  Returns the current working directory as a Pathname.
 
               # File pathname.rb, line 974
def Pathname.getwd() self.new(Dir.getwd) end
             
            See Dir.glob.  Returns or yields Pathname objects.
 
               # File pathname.rb, line 965
def Pathname.glob(*args) # :yield: p
  if block_given?
    Dir.glob(*args) {|f| yield self.new(f) }
  else
    Dir.glob(*args).map {|f| self.new(f) }
  end
end
             
            Create a Pathname object from the given String
(or String-like object). If path contains a NUL character
(\0), an ArgumentError is raised.
 
               # File pathname.rb, line 210
def initialize(path)
  path = path.__send__(TO_PATH) if path.respond_to? TO_PATH
  @path = path.dup
  if /\0/ =~ @path
    raise ArgumentError, "pathname contains \\0: #{@path.inspect}"
  end
  self.taint if @path.tainted?
end
             
            Pathname#+ appends a pathname fragment to this one to produce a new Pathname object.
p1 = Pathname.new("/usr") # Pathname:/usr p2 = p1 + "bin/ruby" # Pathname:/usr/bin/ruby p3 = p1 + "/etc/passwd" # Pathname:/etc/passwd
This method doesn't access the file system; it is pure string manipulation.
 
               # File pathname.rb, line 614
def +(other)
  other = Pathname.new(other) unless Pathname === other
  Pathname.new(plus(@path, other.to_s))
end
             
            Provides for comparing pathnames, case-sensitively.
 
               # File pathname.rb, line 238
def <=>(other)
  return nil unless Pathname === other
  @path.tr('/', "\0") <=> other.to_s.tr('/', "\0")
end
             
            Compare this pathname with other.  The comparison is
string-based. Be aware that two different paths (foo.txt and
./foo.txt) can refer to the same file.
 
               # File pathname.rb, line 230
def ==(other)
  return false unless Pathname === other
  other.to_s == @path
end
             
            to_path is implemented so Pathname objects are usable with File.open, etc.
Predicate method for testing whether a path is absolute. It returns
true if the pathname begins with a slash.
 
               # File pathname.rb, line 521
def absolute?
  !relative?
end
             
            Iterates over and yields a new Pathname object for each element in the given path in ascending order.
Pathname.new('/path/to/some/file.rb').ascend {|v| p v} #<Pathname:/path/to/some/file.rb> #<Pathname:/path/to/some> #<Pathname:/path/to> #<Pathname:/path> #<Pathname:/> Pathname.new('path/to/some/file.rb').ascend {|v| p v} #<Pathname:path/to/some/file.rb> #<Pathname:path/to/some> #<Pathname:path/to> #<Pathname:path>
It doesn't access actual filesystem.
This method is available since 1.8.5.
 
               # File pathname.rb, line 594
def ascend
  path = @path
  yield self
  while r = chop_basename(path)
    path, name = r
    break if path.empty?
    yield self.class.new(del_trailing_separator(path))
  end
end
             
            See File.atime.  Returns last access time.
 
               # File pathname.rb, line 795
def atime() File.atime(@path) end
             
            See File.basename.  Returns the last component of the path.
 
               # File pathname.rb, line 856
def basename(*args) self.class.new(File.basename(@path, *args)) end
             
            See FileTest.blockdev?.
 
               # File pathname.rb, line 890
def blockdev?() FileTest.blockdev?(@path) end
             
            See FileTest.chardev?.
 
               # File pathname.rb, line 893
def chardev?() FileTest.chardev?(@path) end
             
            #chdir is obsoleted at 1.8.1.
 
               # File pathname.rb, line 978
def chdir(&block)
  warn "Pathname#chdir is obsoleted.  Use Dir.chdir."
  Dir.chdir(@path, &block)
end
             
            Returns the children of the directory (files and subdirectories, not
recursive) as an array of Pathname objects.  By
default, the returned pathnames will have enough information to access the
files.  If you set with_directory to false, then
the returned pathnames will contain the filename only.
For example:
p = Pathname("/usr/lib/ruby/1.8")
p.children
    # -> [ Pathname:/usr/lib/ruby/1.8/English.rb,
           Pathname:/usr/lib/ruby/1.8/Env.rb,
           Pathname:/usr/lib/ruby/1.8/abbrev.rb, ... ]
p.children(false)
    # -> [ Pathname:English.rb, Pathname:Env.rb, Pathname:abbrev.rb, ... ]
Note that the result never contain the entries . and
.. in the directory because they are not children.
This method has existed since 1.8.1.
 
               # File pathname.rb, line 701
def children(with_directory=true)
  with_directory = false if @path == '.'
  result = []
  Dir.foreach(@path) {|e|
    next if e == '.' || e == '..'
    if with_directory
      result << self.class.new(File.join(@path, e))
    else
      result << self.class.new(e)
    end
  }
  result
end
             
            See File.chmod.  Changes permissions.
 
               # File pathname.rb, line 804
def chmod(mode) File.chmod(mode, @path) end
             
            See File.chown.  Change owner and group of file.
 
               # File pathname.rb, line 810
def chown(owner, group) File.chown(owner, group, @path) end
             
            #chroot is obsoleted at 1.8.1.
 
               # File pathname.rb, line 984
def chroot
  warn "Pathname#chroot is obsoleted.  Use Dir.chroot."
  Dir.chroot(@path)
end
             
            Returns clean pathname of self with consecutive slashes and
useless dots removed.  The filesystem is not accessed.
If consider_symlink is true, then a more
conservative algorithm is used to avoid breaking symbolic linkages.  This
may retain more .. entries than absolutely necessary, but
without accessing the filesystem, this can't be avoided.  See realpath.
 
               # File pathname.rb, line 338
def cleanpath(consider_symlink=false)
  if consider_symlink
    cleanpath_conservative
  else
    cleanpath_aggressive
  end
end
             
            See File.ctime.  Returns last (directory entry, not file)
change time.
 
               # File pathname.rb, line 798
def ctime() File.ctime(@path) end
             
            Iterates over and yields a new Pathname object for each element in the given path in descending order.
Pathname.new('/path/to/some/file.rb').descend {|v| p v} #<Pathname:/> #<Pathname:/path> #<Pathname:/path/to> #<Pathname:/path/to/some> #<Pathname:/path/to/some/file.rb> Pathname.new('path/to/some/file.rb').descend {|v| p v} #<Pathname:path> #<Pathname:path/to> #<Pathname:path/to/some> #<Pathname:path/to/some/file.rb>
It doesn't access actual filesystem.
This method is available since 1.8.5.
 
               # File pathname.rb, line 567
def descend
  vs = []
  ascend {|v| vs << v }
  vs.reverse_each {|v| yield v }
  nil
end
             
            #dir_foreach is obsoleted at 1.8.1.
 
               # File pathname.rb, line 1002
def dir_foreach(*args, &block)
  warn "Pathname#dir_foreach is obsoleted.  Use Pathname#each_entry."
  each_entry(*args, &block)
end
             
            See FileTest.directory?.
 
               # File pathname.rb, line 908
def directory?() FileTest.directory?(@path) end
             
            See File.dirname.  Returns all but the last component of the
path.
 
               # File pathname.rb, line 859
def dirname() self.class.new(File.dirname(@path)) end
             
            Iterates over the entries (files and subdirectories) in the directory. It yields a Pathname object for each entry.
This method has existed since 1.8.1.
 
               # File pathname.rb, line 997
def each_entry(&block) # :yield: p
  Dir.foreach(@path) {|f| yield self.class.new(f) }
end
             
            Iterates over each component of the path.
Pathname.new("/usr/bin/ruby").each_filename {|filename| ... }
  # yields "usr", "bin", and "ruby".
            
            
             
               # File pathname.rb, line 540
def each_filename # :yield: filename
  return to_enum(__method__) unless block_given?
  prefix, names = split_names(@path)
  names.each {|filename| yield filename }
  nil
end
             
            each_line iterates over the line in the file. It yields a String object for each line.
This method has existed since 1.8.1.
 
               # File pathname.rb, line 770
def each_line(*args, &block) # :yield: line
  IO.foreach(@path, *args, &block)
end
             
            Return the entries (files and subdirectories) in the directory, each as a Pathname object.
 
               # File pathname.rb, line 991
def entries() Dir.entries(@path).map {|f| self.class.new(f) } end
             
            See FileTest.executable?.
 
               # File pathname.rb, line 896
def executable?() FileTest.executable?(@path) end
             
            See FileTest.executable_real?.
 
               # File pathname.rb, line 899
def executable_real?() FileTest.executable_real?(@path) end
             
            See FileTest.exist?.
 
               # File pathname.rb, line 902
def exist?() FileTest.exist?(@path) end
             
            See File.expand_path.
 
               # File pathname.rb, line 865
def expand_path(*args) self.class.new(File.expand_path(@path, *args)) end
             
            See File.extname.  Returns the file's extension.
 
               # File pathname.rb, line 862
def extname() File.extname(@path) end
             
            See FileTest.file?.
 
               # File pathname.rb, line 911
def file?() FileTest.file?(@path) end
             
            #find is an iterator to traverse a directory tree in a depth first manner. It yields a Pathname for each file under “this” directory.
Since it is implemented by find.rb, Find.prune
can be used to control the traverse.
If self is ., yielded pathnames begin with a
filename in the current directory, not ./.
 
               # File pathname.rb, line 1031
def find(&block) # :yield: p
  require 'find'
  if @path == '.'
    Find.find(@path) {|f| yield self.class.new(f.sub(%r{\A\./}, '')) }
  else
    Find.find(@path) {|f| yield self.class.new(f) }
  end
end
             
            See File.fnmatch.  Return true if the receiver
matches the given pattern.
 
               # File pathname.rb, line 817
def fnmatch(pattern, *args) File.fnmatch(pattern, @path, *args) end
             
            See File.fnmatch? (same as fnmatch).
 
               # File pathname.rb, line 820
def fnmatch?(pattern, *args) File.fnmatch?(pattern, @path, *args) end
             
            This method is obsoleted at 1.8.1. Use each_line or each_entry.
 
               # File pathname.rb, line 1075
def foreach(*args, &block)
  warn "Pathname#foreach is obsoleted.  Use each_line or each_entry."
  if FileTest.directory? @path
    # For polymorphism between Dir.foreach and IO.foreach,
    # Pathname#foreach doesn't yield Pathname object.
    Dir.foreach(@path, *args, &block)
  else
    IO.foreach(@path, *args, &block)
  end
end
             
            #foreachline is obsoleted at 1.8.1. Use each_line.
 
               # File pathname.rb, line 775
def foreachline(*args, &block)
  warn "Pathname#foreachline is obsoleted.  Use Pathname#each_line."
  each_line(*args, &block)
end
             
             
               # File pathname.rb, line 221
def freeze() super; @path.freeze; self end
             
            See File.ftype.  Returns “type” of file (“file”, “directory”,
etc).
 
               # File pathname.rb, line 824
def ftype() File.ftype(@path) end
             
            See FileTest.grpowned?.
 
               # File pathname.rb, line 905
def grpowned?() FileTest.grpowned?(@path) end
             
            #join joins pathnames.
path0.join(path1, ..., pathN) is the same as path0 +
path1 + ... + pathN.
 
               # File pathname.rb, line 667
def join(*args)
  args.unshift self
  result = args.pop
  result = Pathname.new(result) unless Pathname === result
  return result if result.absolute?
  args.reverse_each {|arg|
    arg = Pathname.new(arg) unless Pathname === arg
    result = arg + result
    return result if result.absolute?
  }
  result
end
             
            See File.lchmod.
 
               # File pathname.rb, line 807
def lchmod(mode) File.lchmod(mode, @path) end
             
            See File.lchown.
 
               # File pathname.rb, line 813
def lchown(owner, group) File.lchown(owner, group, @path) end
             
            #link is confusing and obsoleted because the receiver/argument order is inverted to corresponding system call.
 
               # File pathname.rb, line 873
def link(old)
  warn 'Pathname#link is obsoleted.  Use Pathname#make_link.'
  File.link(old, @path)
end
             
            See File.lstat.
 
               # File pathname.rb, line 844
def lstat() File.lstat(@path) end
             
            See File.link.  Creates a hard link.
 
               # File pathname.rb, line 827
def make_link(old) File.link(old, @path) end
             
            See File.symlink.  Creates a symbolic link.
 
               # File pathname.rb, line 847
def make_symlink(old) File.symlink(old, @path) end
             
            See Dir.mkdir.  Create the referenced directory.
 
               # File pathname.rb, line 1008
def mkdir(*args) Dir.mkdir(@path, *args) end
             
            See FileUtils.mkpath.  Creates a full path, including any
intermediate directories that don't yet exist.
 
               # File pathname.rb, line 1045
def mkpath
  require 'fileutils'
  FileUtils.mkpath(@path)
  nil
end
             
            mountpoint? returns true if self points to a
mountpoint.
 
               # File pathname.rb, line 497
def mountpoint?
  begin
    stat1 = self.lstat
    stat2 = self.parent.lstat
    stat1.dev == stat2.dev && stat1.ino == stat2.ino ||
      stat1.dev != stat2.dev
  rescue Errno::ENOENT
    false
  end
end
             
            See File.mtime.  Returns last modification time.
 
               # File pathname.rb, line 801
def mtime() File.mtime(@path) end
             
            See File.open.  Opens the file for reading or writing.
 
               # File pathname.rb, line 830
def open(*args, &block) # :yield: file
  File.open(@path, *args, &block)
end
             
            See Dir.open.
 
               # File pathname.rb, line 1014
def opendir(&block) # :yield: dir
  Dir.open(@path, &block)
end
             
            See FileTest.owned?.
 
               # File pathname.rb, line 920
def owned?() FileTest.owned?(@path) end
             
            parent returns the parent directory.
This is same as self + '..'.
 
               # File pathname.rb, line 492
def parent
  self + '..'
end
             
            See FileTest.pipe?.
 
               # File pathname.rb, line 914
def pipe?() FileTest.pipe?(@path) end
             
            See IO.read.  Returns all the bytes from the file, or the
first N if specified.
 
               # File pathname.rb, line 782
def read(*args) IO.read(@path, *args) end
             
            See FileTest.readable?.
 
               # File pathname.rb, line 923
def readable?() FileTest.readable?(@path) end
             
            See FileTest.readable_real?.
 
               # File pathname.rb, line 929
def readable_real?() FileTest.readable_real?(@path) end
             
            See IO.readlines.  Returns all the lines from the file.
 
               # File pathname.rb, line 785
def readlines(*args) IO.readlines(@path, *args) end
             
            See File.readlink.  Read symbolic link.
 
               # File pathname.rb, line 835
def readlink() self.class.new(File.readlink(@path)) end
             
            Returns a real (absolute) pathname of self in the actual
filesystem. The real pathname doesn't contain symlinks or useless dots.
No arguments should be given; the old behaviour is obsoleted.
 
               # File pathname.rb, line 478
def realpath
  path = @path
  prefix, names = split_names(path)
  if prefix == ''
    prefix, names2 = split_names(Dir.pwd)
    names = names2 + names
  end
  prefix, *names = realpath_rec(prefix, names, {})
  self.class.new(prepend_prefix(prefix, File.join(*names)))
end
             
            The opposite of absolute?
 
               # File pathname.rb, line 526
def relative?
  path = @path
  while r = chop_basename(path)
    path, basename = r
  end
  path == ''
end
             
            relative_path_from
returns a relative path from the argument to the receiver.  If
self is absolute, the argument must be absolute too.  If
self is relative, the argument must be relative too.
relative_path_from doesn't access the filesystem. It assumes no symlinks.
ArgumentError is raised when it cannot find a relative path.
This method has existed since 1.8.1.
 
               # File pathname.rb, line 726
def relative_path_from(base_directory)
  dest_directory = self.cleanpath.to_s
  base_directory = base_directory.cleanpath.to_s
  dest_prefix = dest_directory
  dest_names = []
  while r = chop_basename(dest_prefix)
    dest_prefix, basename = r
    dest_names.unshift basename if basename != '.'
  end
  base_prefix = base_directory
  base_names = []
  while r = chop_basename(base_prefix)
    base_prefix, basename = r
    base_names.unshift basename if basename != '.'
  end
  unless SAME_PATHS[dest_prefix, base_prefix]
    raise ArgumentError, "different prefix: #{dest_prefix.inspect} and #{base_directory.inspect}"
  end
  while !dest_names.empty? &&
        !base_names.empty? &&
        SAME_PATHS[dest_names.first, base_names.first]
    dest_names.shift
    base_names.shift
  end
  if base_names.include? '..'
    raise ArgumentError, "base_directory has ..: #{base_directory.inspect}"
  end
  base_names.fill('..')
  relpath_names = base_names + dest_names
  if relpath_names.empty?
    Pathname.new('.')
  else
    Pathname.new(File.join(*relpath_names))
  end
end
             
            See File.rename.  Rename the file.
 
               # File pathname.rb, line 838
def rename(to) File.rename(@path, to) end
             
            See Dir.rmdir.  Remove the referenced directory.
 
               # File pathname.rb, line 1011
def rmdir() Dir.rmdir(@path) end
             
            See FileUtils.rm_r.  Deletes a directory and all beneath it.
 
               # File pathname.rb, line 1052
def rmtree
  # The name "rmtree" is borrowed from File::Path of Perl.
  # File::Path provides "mkpath" and "rmtree".
  require 'fileutils'
  FileUtils.rm_r(@path)
  nil
end
             
            root? is a predicate for root
directories.  I.e. it returns true if the pathname consists of
consecutive slashes.
It doesn't access actual filesystem.  So it may return
false for some pathnames which points to roots such as
/usr/...
 
               # File pathname.rb, line 515
def root?
  !!(chop_basename(@path) == nil && /#{SEPARATOR_PAT}/o =~ @path)
end
             
            See FileTest.setgid?.
 
               # File pathname.rb, line 935
def setgid?() FileTest.setgid?(@path) end
             
            See FileTest.setuid?.
 
               # File pathname.rb, line 932
def setuid?() FileTest.setuid?(@path) end
             
            See FileTest.size.
 
               # File pathname.rb, line 938
def size() FileTest.size(@path) end
             
            See FileTest.size?.
 
               # File pathname.rb, line 941
def size?() FileTest.size?(@path) end
             
            See FileTest.socket?.
 
               # File pathname.rb, line 917
def socket?() FileTest.socket?(@path) end
             
            See File.stat.  Returns a File::Stat object.
 
               # File pathname.rb, line 841
def stat() File.stat(@path) end
             
            See FileTest.sticky?.
 
               # File pathname.rb, line 944
def sticky?() FileTest.sticky?(@path) end
             
            Return a pathname which is substituted by String#sub.
 
               # File pathname.rb, line 260
def sub(pattern, *rest, &block)
  if block
    path = @path.sub(pattern, *rest) {|*args|
      begin
        old = Thread.current[:pathname_sub_matchdata]
        Thread.current[:pathname_sub_matchdata] = $~
        eval("$~ = Thread.current[:pathname_sub_matchdata]", block.binding)
      ensure
        Thread.current[:pathname_sub_matchdata] = old
      end
      yield *args
    }
  else
    path = @path.sub(pattern, *rest)
  end
  self.class.new(path)
end
             
            Return a pathname which the extension of the basename is substituted by repl.
If self has no extension part, repl is appended.
 
               # File pathname.rb, line 290
def sub_ext(repl)
  ext = File.extname(@path)
  self.class.new(@path.chomp(ext) + repl)
end
             
            #symlink is confusing and obsoleted because the receiver/argument order is inverted to corresponding system call.
 
               # File pathname.rb, line 880
def symlink(old)
  warn 'Pathname#symlink is obsoleted.  Use Pathname#make_symlink.'
  File.symlink(old, @path)
end
             
            See FileTest.symlink?.
 
               # File pathname.rb, line 947
def symlink?() FileTest.symlink?(@path) end
             
            See IO.sysopen.
 
               # File pathname.rb, line 788
def sysopen(*args) IO.sysopen(@path, *args) end
             
             
               # File pathname.rb, line 222
def taint() super; @path.taint; self end
             
            Return the path as a String.
 
               # File pathname.rb, line 248
def to_s
  @path.dup
end
             
            See File.truncate.  Truncate the file to length
bytes.
 
               # File pathname.rb, line 850
def truncate(length) File.truncate(@path, length) end
             
            Removes a file or directory, using File.unlink or
Dir.unlink as necessary.
 
               # File pathname.rb, line 1065
def unlink()
  begin
    Dir.unlink @path
  rescue Errno::ENOTDIR
    File.unlink @path
  end
end
             
             
               # File pathname.rb, line 223
def untaint() super; @path.untaint; self end
             
            See File.utime.  Update the access and modification times.
 
               # File pathname.rb, line 853
def utime(atime, mtime) File.utime(atime, mtime, @path) end
             
            See FileTest.world_readable?.
 
               # File pathname.rb, line 926
def world_readable?() FileTest.world_readable?(@path) end
             
            See FileTest.world_writable?.
 
               # File pathname.rb, line 953
def world_writable?() FileTest.world_writable?(@path) end
             
            See FileTest.writable?.
 
               # File pathname.rb, line 950
def writable?() FileTest.writable?(@path) end