Pathname represents the name of a file or directory on the filesystem, but not the file itself.
The pathname depends on the Operating System: Unix, Windows, etc. This library works with pathnames of local OS, however non-Unix pathnames are supported experimentally.
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 goal 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.
Examples
Example 1: Using Pathname
require 'pathname'
pn = Pathname.new("/usr/bin/ruby")
size = pn.size # 27662
isdir = pn.directory? # false
dir = pn.dirname # Pathname:/usr/bin
base = pn.basename # Pathname:ruby
dir, base = pn.split # [Pathname:/usr/bin, Pathname:ruby]
data = pn.read
pn.open { |f| _ }
pn.each_line { |line| _ }
Example 2: Using standard Ruby
pn = "/usr/bin/ruby"
size = File.size(pn) # 27662
isdir = File.directory?(pn) # false
dir = File.dirname(pn) # "/usr/bin"
base = File.basename(pn) # "ruby"
dir, base = File.split(pn) # ["/usr/bin", "ruby"]
data = File.read(pn)
File.open(pn) { |f| _ }
File.foreach(pn) { |line| _ }
Example 3: Special features
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, ...]
Breakdown of functionality
Core methods
These methods are effectively manipulating a String, because that's all a path is. None of these access the file system except for mountpoint?, children, each_child, realdirpath and realpath.
-
+
File status predicate methods
These methods are a facade for FileTest:
File property and manipulation methods
These methods are a facade for File:
-
chown(owner, group)
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lchown(owner, group)
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fnmatch(pattern, *args)
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fnmatch?(pattern, *args)
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open(*args, &block)
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utime(atime, mtime)
Directory methods
These methods are a facade for Dir:
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each_entry(&block)
IO
These methods are a facade for IO:
-
each_line(*args, &block)
Utilities
These methods are a mixture of Find, FileUtils, and others:
Method documentation
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.