オブジェクト指向Lsコマンドプログラム作成

07.ls_object/basic_format.rb

@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+require_relative 'file_info'
+
+class BasicFormat
+  def initialize(file_paths)
+    @files = file_paths.map { |file_path| FileInfo.new(file_path) }
+  end
+
+  def format_lines
+    NotImplementedError
+  end
+end

07.ls_object/detailed_format.rb

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+# frozen_string_literal: true
+
+require_relative 'basic_format'
+
+class DetailedFormat < BasicFormat
+  def format_lines
+    @files.map do |file|
+      file.full_info_format(max_lengths)
+    end
+  end
+
+  def calculate_total_blocks
+    @files.sum(&:blocks)
+  end
+
+  private
+
+  def max_lengths
+    max_lengths = {}
+    max_lengths[:size] = @files.map { |file| file.size.to_s.length }.max
+    max_lengths[:nlink] = @files.map { |file| file.link_num.to_s.length }.max
+    max_lengths[:user]  = @files.map { |file| file.user.length }.max
+    max_lengths[:group] = @files.map { |file| file.group.length }.max
+
+    max_lengths
+  end
+end

07.ls_object/file_info.rb

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+# frozen_string_literal: true
+
+require 'etc'
+
+PERMISSIONS = { '0' => '---', '1' => '--x', '2' => '-w-', '3' => '-wx',
+                '4' => 'r--', '5' => 'r-x', '6' => 'rw-', '7' => 'rwx' }.freeze
+
+class FileInfo
+  def initialize(file_path)
+    @file_path = file_path
+  end
+
+  def base_name
+    File.basename(@file_path)
+  end
+
+  def type
+    file_lstat = File.lstat(@file_path)
+    if file_lstat.directory?
+      'd'
+    elsif file_lstat.symlink?
+      'l'
+    else
+      '-'
+    end
+  end
+
+  def mode
+    file_stat.mode.to_s(8).slice(-3, 3).chars.to_a.map { |n| PERMISSIONS[n] }.join
+  end
+
+  def link_num
+    file_stat.nlink
+  end
+
+  def size
+    file_stat.size
+  end
+
+  def user
+    Etc.getpwuid(file_stat.uid).name
+  end
+
+  def group
+    Etc.getgrgid(file_stat.gid).name
+  end
+
+  def last_access_time
+    file_stat.mtime.strftime('%_m %_d %H:%M')
+  end
+
+  def symlink?
+    mode_num = File.lstat(@file_path).mode.to_s(8)
+    mode_num[0, 2] == '12'
+  end
+
+  def blocks
+    file_stat.blocks
+  end
+
+  def full_info_format(max_lengths)
+    "#{type}#{mode}  "\
+    "#{link_num.to_s.rjust(max_lengths[:nlink])} "\
+    "#{user.rjust(max_lengths[:user])}  #{group.to_s.rjust(max_lengths[:group])}  "\
+    "#{size.to_s.rjust(max_lengths[:size])} "\
+    "#{last_access_time} #{base_name}"\
+    "#{" -> #{File.readlink(@file_path)}" if symlink?}"
+  end
+
+  private
+
+  def file_stat
+    File::Stat.new(@file_path)
+  end
+end

07.ls_object/ls.rb

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+# frozen_string_literal: true
+
+require_relative 'ls_command'
+require 'optparse'
+
+opt = OptionParser.new
+options = {}
+opt.on('-a') { |v| options[:a] = v }
+opt.on('-r') { |v| options[:r] = v }
+opt.on('-l') { |v| options[:l] = v }
+opt.parse!(ARGV)
+
+path = ARGV[0] || '.'
+LsCommand.new(path, options).display

07.ls_object/ls_command.rb

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+# frozen_string_literal: true
+
+require_relative 'short_format'
+require_relative 'detailed_format'
+
+class LsCommand
+  def initialize(path, options)
+    @path = path
+    @options = options
+  end
+
+  def display
+    puts "total #{formatter.calculate_total_blocks}" if @options[:l]
+    puts formatter.format_lines
+  end
+
+  private
+
+  def file_paths
+    file_pattern = File.join(@path, '*')
+    file_paths = @options[:a] ? Dir.glob(file_pattern, File::FNM_DOTMATCH) : Dir.glob(file_pattern)
+    @options[:r] ? file_paths.reverse : file_paths
+  end
+
+  def formatter
+    @options[:l] ? DetailedFormat.new(file_paths) : ShortFormat.new(file_paths)
+  end
+end

07.ls_object/short_format.rb

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+# frozen_string_literal: true
+
+require_relative 'basic_format'
+
+class ShortFormat < BasicFormat
+  COLUMN_NUM = 3
+
+  def format_lines
+    files_grouped_into_lines.map do |line|
+      line.map do |file|
+        file_name = file.base_name
+        file_name.ljust(max_length)
+      end.join('      ')
+    end
+  end
+
+  private
+
+  def files_grouped_into_lines
+    total_line_count = (@files.size.to_f / COLUMN_NUM).ceil
+    files_sliced = @files.each_slice(total_line_count).to_a
+
+    total_line_count.times.map do |index|
+      files_sliced.map { |files| files[index] }.compact
+    end
+  end
+
+  def max_length
+    @files.map { |file| file.base_name.size }.max
+  end
+end