Implement the basename() function to stdlib.

README.markdown

@@ -95,6 +95,16 @@ string
 
 - *Type*: rvalue
 
+basename
+-------
+Returns the `basename` of a path.
+
+*Examples:*
+
+    basename('/path/to/a/file.ext')
+
+Would return: 'file.ext'
+
 bool2num
 --------
 Converts a boolean to a number. Converts the values:

lib/puppet/parser/functions/basename.rb

@@ -0,0 +1,12 @@
+module Puppet::Parser::Functions
+  newfunction(:basename, :type => :rvalue, :arity => 1, doc => <<-EOS
+    Returns the basename of a path.
+    EOS
+  ) do |arguments|
+
+    path = arguments[0]
+    return File.basename(path)
+  end
+end
+
+# vim: set ts=2 sw=2 et :

spec/acceptance/basename_spec.rb

@@ -0,0 +1,42 @@
+#! /usr/bin/env ruby -S rspec
+require 'spec_helper_acceptance'
+
+describe 'basename function', :unless => UNSUPPORTED_PLATFORMS.include?(fact('operatingsystem')) do
+  describe 'success' do
+    context 'absolute path' do
+      it 'returns the basename' do
+        pp = <<-EOS
+        $a = '/path/to/a/file.txt'
+        $b = 'file.txt'
+        $o = basename($a)
+        if $o == $b {
+          notify { 'output correct': }
+        }
+        EOS
+
+        apply_manifest(pp, :catch_failures => true) do |r|
+          expect(r.stdout).to match(/Notice: output correct/)
+        end
+      end
+    end
+    context 'relative path' do
+      it 'returns the basename' do
+        pp = <<-EOS
+        $a = 'path/to/a/file.txt'
+        $b = 'file.txt'
+        $o = basename($a)
+        if $o == $b {
+          notify { 'output correct': }
+        }
+        EOS
+
+        apply_manifest(pp, :catch_failures => true) do |r|
+          expect(r.stdout).to match(/Notice: output correct/)
+        end
+      end
+    end
+  end
+  describe 'failure' do
+    it 'handles improper argument counts'
+  end
+end

spec/functions/basename_spec.rb

@@ -0,0 +1,24 @@
+#! /usr/bin/env ruby -S rspec
+require 'spec_helper'
+
+describe "the basename function" do
+  let(:scope) { PuppetlabsSpec::PuppetInternals.scope }
+
+  it "should exist" do
+    expect(Puppet::Parser::Functions.function("basename")).to eq("function_basename")
+  end
+
+  it "should raise a ParseError if there is less than 1 arguments" do
+    expect { scope.function_basename([]) }.to( raise_error(Puppet::ParseError))
+  end
+
+  it "should return basename for an absolute path" do
+    result = scope.function_basename(['/path/to/a/file.ext'])
+    expect(result).to(eq('file.ext'))
+  end
+
+  it "should return basename for a relative path" do
+    result = scope.function_basename(['path/to/a/file.ext'])
+    expect(result).to(eq('file.ext'))
+  end
+end