class String

"/path/to/file.txt"

Returns:

}
ext.downcase
"/path/to/file.TXT".pathmap("%X%{.*,*}x") { |ext|

For example:

some arbitrary calculation for the replacement.
If the replacement text is '*', then a block may be provided to perform

"bin/org/onestepback/proj/A.class"

returns:

"src/org/onestepback/proj/A.java".pathmap("%{^src,bin}X.class")

For example:

reasonable).
excluded from both the pattern and replacement text (let's keep parsing
used in the replacement text. Curly braces, commas and semi-colons are
Regular expressions may be used for the pattern, and back refs may be

semi-colons (e.g. "%{old,new;src,bin}d").
"%{old,new}d"). Multiple replacement specs should be separated by
after the % character but before the operator letter. (e.g.
by a comma and are enclosed by curly braces. The replacement spec comes
particular part of the path. The pattern and replacement are separated
pattern/replacement argument to perform simple string substitutions on a
Also the %d, %p, %f, %n, %x, and %X operators can take a

'a/b/c/d/file.txt'.pathmap("%-2d") => 'c/d'
'a/b/c/d/file.txt'.pathmap("%2d") => 'a/b'

Examples:

|+n+| directories from the right hand side of the path.
starting from the left hand side. If +n+ is negative, return (up to)
number is positive, only return (up to) +n+ directories in the path,
The %d specifier can also have a numeric prefix (e.g. '%2d'). If the

* %% -- A percent sign.
the standard file separator.
* %s -- The alternate file separator if defined, otherwise use
* %X -- Everything *but* the file extension.
is no extension.
* %x -- The file extension of the path. An empty string if there
* %d -- The directory list of the path.
* %n -- The file name of the path without its file extension.
but without any directories.
* %f -- The base file name of the path, with its file extension,
* %p -- The complete path.

recognized:
controls the details of the mapping. The following special patterns are
Map the path according to the given specification. The specification

def pathmap(spec=nil, &block)
  return self if spec.nil?
  result = ''
  spec.scan(/%\{[^}]*\}-?\d*[sdpfnxX%]|%-?\d+d|%.|[^%]+/) do |frag|
    case frag
    when '%f'
      result << File.basename(self)
    when '%n'
      result << File.basename(self).ext
    when '%d'
      result << File.dirname(self)
    when '%x'
      result << File.extname(self)
    when '%X'
      result << self.ext
    when '%p'
      result << self
    when '%s'
      result << (File::ALT_SEPARATOR || File::SEPARATOR)
    when '%-'
      # do nothing
    when '%%'
      result << "%"
    when /%(-?\d+)d/
      result << pathmap_partial($1.to_i)
    when /^%\{([^}]*)\}(\d*[dpfnxX])/
      patterns, operator = $1, $2
      result << pathmap('%' + operator).pathmap_replace(patterns, &block)
    when /^%/
      fail ArgumentError, "Unknown pathmap specifier #{frag} in '#{spec}'"
    else
      result << frag
    end
  end
  result
end