brew/Library/Homebrew/keg.rb

require 'extend/pathname'

class Keg < Pathname
  def initialize path
    super path
    raise "#{to_s} is not a valid keg" unless parent.parent.realpath == HOMEBREW_CELLAR.realpath
    raise "#{to_s} is not a directory" unless directory?
  end

  # locale-specific directories have the form language[_territory][.codeset][@modifier]
  LOCALEDIR_RX = /(locale|man)\/([a-z]{2}|C|POSIX)(_[A-Z]{2})?(\.[a-zA-Z\-0-9]+(@.+)?)?/
  INFOFILE_RX = %r[info/([^.].*?\.info|dir)$]

  # if path is a file in a keg then this will return the containing Keg object
  def self.for path
    path = path.realpath
    while not path.root?
      return Keg.new(path) if path.parent.parent == HOMEBREW_CELLAR.realpath
      path = path.parent.realpath # realpath() prevents root? failing
    end
    raise NotAKegError, "#{path} is not inside a keg"
  end

  def uninstall
    rmtree
    parent.rmdir_if_possible
  end

  def unlink
    n=0

    %w[bin etc lib include sbin share var].map{ |d| self/d }.each do |src|
      next unless src.exist?
      src.find do |src|
        next if src == self
        dst=HOMEBREW_PREFIX+src.relative_path_from(self)

        # check whether the file to be unlinked is from the current keg first
        if !dst.symlink? || !dst.exist? || src != dst.resolved_path
          next
        end

        dst.uninstall_info if dst.to_s =~ INFOFILE_RX and ENV['HOMEBREW_KEEP_INFO']
        dst.unlink
        dst.parent.rmdir_if_possible
        n+=1
        Find.prune if src.directory?
      end
    end
    linked_keg_record.unlink if linked_keg_record.symlink?
    n
  end

  def fname
    parent.basename.to_s
  end

  def linked_keg_record
    @linked_keg_record ||= HOMEBREW_REPOSITORY/"Library/LinkedKegs"/fname
  end

  def linked?
    linked_keg_record.directory? and self == linked_keg_record.realpath
  end

  def completion_installed? shell
    dir = case shell
      when :bash then self/'etc/bash_completion.d'
      when :zsh then self/'share/zsh/site-functions'
      end
    return if dir.nil?
    dir.directory? and not dir.children.length.zero?
  end

  def version
    require 'version'
    Version.new(basename.to_s)
  end

  def basename
    Pathname.new(self.to_s).basename
  end

  def link mode=nil
    raise "Cannot link #{fname}\nAnother version is already linked: #{linked_keg_record.realpath}" if linked_keg_record.directory?

    # these are used by the ObserverPathnameExtension to count the number
    # of files and directories linked
    $n=0
    $d=0

    share_mkpaths=%w[aclocal doc info locale man]+(1..8).collect{|x|"man/man#{x}"}
    # cat pages are rare, but exist so the directories should be created
    share_mkpaths << (1..8).collect{ |x| "man/cat#{x}" }

    # yeah indeed, you have to force anything you need in the main tree into
    # these dirs REMEMBER that *NOT* everything needs to be in the main tree
    link_dir('etc', mode) {:mkpath}
    link_dir('bin', mode) {:skip_dir}
    link_dir('sbin', mode) {:skip_dir}
    link_dir('include', mode) {:link}

    link_dir('share', mode) do |path|
      case path.to_s
      when 'locale/locale.alias' then :skip_file
      when INFOFILE_RX then ENV['HOMEBREW_KEEP_INFO'] ? :info : :skip_file
      when LOCALEDIR_RX then :mkpath
      when *share_mkpaths then :mkpath
      when /^zsh/ then :mkpath
      else :link
      end
    end

    link_dir('lib', mode) do |path|
      case path.to_s
      when 'charset.alias' then :skip_file
      # pkg-config database gets explicitly created
      when 'pkgconfig' then :mkpath
      # lib/language folders also get explicitly created
      when /^gdk-pixbuf/ then :mkpath
      when 'ghc' then :mkpath
      when 'lua' then :mkpath
      when 'node' then :mkpath
      when /^ocaml/ then :mkpath
      when /^perl5/ then :mkpath
      when 'php' then :mkpath
      when /^python[23]\.\d/ then :mkpath
      when 'ruby' then :mkpath
      # Everything else is symlinked to the cellar
      else :link
      end
    end

    linked_keg_record.make_relative_symlink(self) unless mode == :dryrun

    optlink unless mode == :dryrun

    return $n + $d
  rescue Exception
    opoo "Could not link #{fname}. Unlinking..."
    unlink
    raise
  end

  def optlink
    from = HOMEBREW_PREFIX/:opt/fname
    if from.symlink?
      from.delete
    elsif from.directory?
      from.rmdir
    elsif from.exist?
      from.delete
    end
    from.make_relative_symlink(self)
  end

protected
  def resolve_any_conflicts dst
    # if it isn't a directory then a severe conflict is about to happen. Let
    # it, and the exception that is generated will message to the user about
    # the situation
    if dst.symlink? and dst.directory?
      src = (dst.parent+dst.readlink).cleanpath
      keg = Keg.for(src)
      dst.unlink
      keg.link_dir(src) { :mkpath }
      return true
    end
  rescue NotAKegError
    puts "Won't resolve conflicts for symlink #{dst} as it doesn't resolve into the Cellar" if ARGV.verbose?
  end

  def make_relative_symlink dst, src, mode=nil
    if dst.exist? and dst.realpath == src.realpath
      puts "Skipping; already exists: #{dst}" if ARGV.verbose?
    # cf. git-clean -n: list files to delete, don't really link or delete
    elsif mode == :dryrun
      puts dst if dst.exist?
      return
    else
      dst.delete if mode == :force && dst.exist?
      dst.make_relative_symlink src
    end
  end

  # symlinks the contents of self+foo recursively into /usr/local/foo
  def link_dir foo, mode=nil
    root = self+foo
    return unless root.exist?

    root.find do |src|
      next if src == root

      dst = HOMEBREW_PREFIX+src.relative_path_from(self)
      dst.extend ObserverPathnameExtension

      if src.file?
        Find.prune if File.basename(src) == '.DS_Store'

        case yield src.relative_path_from(root)
        when :skip_file, nil
          Find.prune
        when :info
          next if File.basename(src) == 'dir' # skip historical local 'dir' files
          make_relative_symlink dst, src, mode
          dst.install_info
        else
          make_relative_symlink dst, src, mode
        end
      elsif src.directory?
        # if the dst dir already exists, then great! walk the rest of the tree tho
        next if dst.directory? and not dst.symlink?

        # no need to put .app bundles in the path, the user can just use
        # spotlight, or the open command and actual mac apps use an equivalent
        Find.prune if src.extname.to_s == '.app'

        case yield src.relative_path_from(root)
        when :skip_dir
          Find.prune
        when :mkpath
          dst.mkpath unless resolve_any_conflicts(dst)
        else
          unless resolve_any_conflicts(dst)
            make_relative_symlink dst, src, mode
            Find.prune
          end
        end
      end
    end
  end
end

require 'keg_fix_install_names'