sxmrb.rb in sxmrb-0.1.1

- old
+ new
@@ -3,38 +3,114 @@
 require_relative 'sxmrb/version'
 
 require 'shell'
 require 'shellwords'
 
+require 'singleton'
+require 'forwardable'
+
 # SXMO user scripts in ruby.
-module Sxmrb
-  class <<self
-    class Error < StandardError; end
+class Sxmrb
+  include Singleton
 
-    def sh(...)
-      (@_sh ||= Shell.new).system(...)
-    rescue StandardError => e
-      raise Error, e
-    end
+  # Normally when using Singleton there is no way to pass arguments
+  # when instantiating.  The renew hack below allows the singleton
+  # instance to be re-instantiated and can pass arguments at that time;
+  # this was added as an experiment to assist with testing.
+  def initialize(shell: ::Shell.new) # :nodoc:
+    @_sh = shell
+  end
 
-    def menu(prompt: nil)
-      sh String.new.tap { |cmd|
-        if ENV['SSH_CLIENT'] || ENV['SSH_TTY']
-          cmd << 'vis-menu -i -l 18'
-        else
-          cmd << 'dmenu -c -i -l 18'
-          sh 'sxmo_keyboard.sh open'
-        end
+  # Run a system shell command.
+  #
+  # @example
+  #   sh('ls -tr').to_s.lines.last
+  def sh(...)
+    @_sh.system(...)
+  rescue ::StandardError => e
+    raise Error, e
+  end
 
-        cmd << " -p #{prompt.inspect}" if prompt
-      }
-    end
+  # Display a menu using dmenu [X11] or vis-menu [ssh].
+  # A newline-separated list of items is read from standard input.
+  # The selected item is printed to standard output.
+  #
+  # @example
+  #   file = (sh('ls') | menu(prompt: 'File?')).to_s.chomp
+  def menu(prompt: nil)
+    sh String.new.tap { |cmd|
+      if ENV['SSH_CLIENT'] || ENV['SSH_TTY']
+        cmd << 'vis-menu -i -l 18'
+      else
+        cmd << 'dmenu -c -i -l 18'
+        sh 'sxmo_keyboard.sh open'
+      end
 
-    def echo(arg = '')
-      sh("echo #{Shellwords.escape arg.chomp}")
-    end
+      cmd << " -p #{prompt.inspect}" if prompt
+    }
+  end
 
-    def input(prompt:)
-      (echo | menu(prompt: prompt)).to_s.chomp
+  # Run the awk command.
+  #
+  # @example
+  #   print(sh('ls -l') | awk('{print $1}').to_s)
+  def awk(arg = '')
+    sh("awk -e #{Shellwords.escape arg.chomp}")
+  end
+
+  # Run the cat command.
+  #
+  # @example
+  #   print cat('/etc/passwd').to_s
+  def cat(arg = '')
+    sh("cat #{arg.chomp}")
+  end
+
+  # Run the column command.
+  #
+  # @example
+  #   print(sh('ls -l') | column('-t').to_s)
+  def column(arg = '')
+    sh("column #{arg.chomp}")
+  end
+
+  # Run the shell echo command.
+  #
+  # @example
+  #   print echo('Hello World').to_s
+  def echo(arg = '')
+    sh("echo #{Shellwords.escape arg.chomp}")
+  end
+
+  # Run the tac command.
+  #
+  # @example
+  #   print tac('/etc/passwd').to_s
+  def tac(arg = '')
+    sh("tac #{arg.chomp}")
+  end
+
+  # Use a blank #menu to prompt for a value.
+  #
+  # @example
+  #   value = input(prompt: 'Amount?').to_i
+  def input(prompt:)
+    (echo | menu(prompt: prompt)).to_s.chomp
+  end
+
+  class <<self
+    # This evil hack experiment is intended to allow swapping out the
+    # Shell instance when testing.
+    def renew_instance(...) # :nodoc:
+      @singleton__mutex__.synchronize {
+        @singleton__instance__ = new(...)
+      }
     end
+
+    # Forward instance methods to the Singleton instance; false here
+    # excludes ancestor methods.
+    extend Forwardable
+    def_delegators :instance, *Sxmrb.instance_methods(false)
   end
+
+  class Error < ::StandardError; end
 end