From: ara.t.howard@...
Date: 2006-05-09T22:51:09+09:00
Subject: Re: non-static way to get the filename?

On Tue, 9 May 2006, Peter Szinek wrote:

> Hello all,
>
> I am new to Ruby etc. etc. (all the usual disclaimer about how i can not code 
> in Ruby yet etc), so probably because of this i was not able to find 
> something like
>
> myFile.basename
> resp
> myFile.anything_which_returns_a_sensible_filename_like_string
>
> and not
>
> File.basename(myFile)
>
> which i find too verbose for Ruby.
> By browsing the reference  part of the PickAxe 2nd ed, i did not find any 
> alternative to File.basename. Can somebody help me with this?
>
> Thx,
> Peter

     harp:~ > cat a.rb
     require 'pathname'

     pn = Pathname.new __FILE__
     pn = pn.expand_path

     p pn.dirname
     p pn.basename

     tmp = Pathname.new '/tmp'
     p pn.relative_path_from(tmp)


     harp:~ > ruby a.rb
     #<Pathname:/home/ahoward>
     #<Pathname:a.rb>
     #<Pathname:../home/ahoward/a.rb>


and a whole lot more:

     harp:~ > ri Pathname
     -------------------------------------------------------- Class: Pathname

     Pathname
     --------
          Pathname represents a pathname which locates a file in a
          filesystem. It supports only Unix style pathnames. 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.


     Examples
     --------
          Example 1: Using Pathname
            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| _ }

          Example 2: Using standard Ruby
            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| _ }

          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. Except for #mountpoint?, #children, and #realpath,
          they don't access the filesystem.

          *   +

regards.

-a
-- 
be kind whenever possible... it is always possible.
- h.h. the 14th dali lama