User defined methods to be added to String.

Methods
Public Instance methods
ext(newext='')

Replace the file extension with newext. If there is no extension on the string, append the new extension to the end. If the new extension is not given, or is the empty string, remove any existing extension.

ext is a user added method for the String class.

    # File lib/rake.rb, line 84
84:     def ext(newext='')
85:       return self.dup if ['.', '..'].include? self
86:       if newext != ''
87:         newext = (newext =~ /^\./) ? newext : ("." + newext)
88:       end
89:       self.chomp(File.extname(self)) << newext
90:     end
pathmap(spec=nil, &block)

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

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

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

Examples:

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

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

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

For example:

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

returns:

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

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

For example:

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

Returns:

 "/path/to/file.txt"
     # File lib/rake.rb, line 200
200:     def pathmap(spec=nil, &block)
201:       return self if spec.nil?
202:       result = ''
203:       spec.scan(/%\{[^}]*\}-?\d*[sdpfnxX%]|%-?\d+d|%.|[^%]+/) do |frag|
204:         case frag
205:         when '%f'
206:           result << File.basename(self)
207:         when '%n'
208:           result << File.basename(self).ext
209:         when '%d'
210:           result << File.dirname(self)
211:         when '%x'
212:           result << File.extname(self)
213:         when '%X'
214:           result << self.ext
215:         when '%p'
216:           result << self
217:         when '%s'
218:           result << (File::ALT_SEPARATOR || File::SEPARATOR)
219:         when '%-'
220:           # do nothing
221:         when '%%'
222:           result << "%"
223:         when /%(-?\d+)d/
224:           result << pathmap_partial($1.to_i)
225:         when /^%\{([^}]*)\}(\d*[dpfnxX])/
226:           patterns, operator = $1, $2
227:           result << pathmap('%' + operator).pathmap_replace(patterns, &block)
228:         when /^%/
229:           fail ArgumentError, "Unknown pathmap specifier #{frag} in '#{spec}'"
230:         else
231:           result << frag
232:         end
233:       end
234:       result
235:     end
pathmap_explode()

Explode a path into individual components. Used by pathmap.

     # File lib/rake.rb, line 95
 95:     def pathmap_explode
 96:       head, tail = File.split(self)
 97:       return [self] if head == self
 98:       return [tail] if head == '.' || tail == '/'
 99:       return [head, tail] if head == '/'
100:       return head.pathmap_explode + [tail]
101:     end
pathmap_partial(n)

Extract a partial path from the path. Include n directories from the front end (left hand side) if n is positive. Include |n| directories from the back end (right hand side) if n is negative.

     # File lib/rake.rb, line 107
107:     def pathmap_partial(n)
108:       dirs = File.dirname(self).pathmap_explode
109:       partial_dirs =
110:         if n > 0
111:           dirs[0...n]
112:         elsif n < 0
113:           dirs.reverse[0...-n].reverse
114:         else
115:           "."
116:         end
117:       File.join(partial_dirs)
118:     end
pathmap_replace(patterns, &block)

Preform the pathmap replacement operations on the given path. The patterns take the form ‘pat1,rep1;pat2,rep2…’.

     # File lib/rake.rb, line 123
123:     def pathmap_replace(patterns, &block)
124:       result = self
125:       patterns.split(';').each do |pair|
126:         pattern, replacement = pair.split(',')
127:         pattern = Regexp.new(pattern)
128:         if replacement == '*' && block_given?
129:           result = result.sub(pattern, &block)
130:         elsif replacement
131:           result = result.sub(pattern, replacement)
132:         else
133:           result = result.sub(pattern, '')
134:         end
135:       end
136:       result
137:     end