Merge pull request #4 from scientist-labs/ctrl-c

Ctrl c

Author: cpetersen

examples/signal_demo.rb

@@ -0,0 +1,203 @@
+#!/usr/bin/env ruby
+# frozen_string_literal: true
+
+require "bundler/setup"
+require "thor/interactive"
+
+class SignalDemo < Thor
+  include Thor::Interactive::Command
+  
+  configure_interactive(
+    prompt: "signal> ",
+    ctrl_c_behavior: :clear_prompt,  # Default
+    double_ctrl_c_timeout: 0.5        # 500ms window for double Ctrl-C
+  )
+  
+  desc "slow", "Simulate a slow command"
+  def slow
+    puts "Starting slow operation..."
+    5.times do |i|
+      puts "Step #{i + 1}/5"
+      sleep(1)
+    end
+    puts "Done!"
+  rescue Interrupt
+    puts "\nOperation cancelled!"
+  end
+  
+  desc "loop", "Run an infinite loop (test Ctrl-C)"
+  def loop
+    puts "Starting infinite loop (press Ctrl-C to stop)..."
+    counter = 0
+    while true
+      print "\rCounter: #{counter}"
+      counter += 1
+      sleep(0.1)
+    end
+  rescue Interrupt
+    puts "\nLoop stopped at #{counter}"
+  end
+  
+  desc "input", "Test input with special text"
+  def input
+    puts "Type something with Ctrl chars:"
+    puts "  - Ctrl-C to clear and start over"
+    puts "  - Ctrl-D to cancel"
+    puts "  - Enter to submit"
+    
+    print "input> "
+    begin
+      text = $stdin.gets
+      if text
+        puts "You entered: #{text.inspect}"
+      else
+        puts "Cancelled with Ctrl-D"
+      end
+    rescue Interrupt
+      puts "\nInterrupted - input cancelled"
+    end
+  end
+  
+  desc "behaviors", "Demo different Ctrl-C behaviors"
+  def behaviors
+    puts "\n=== Ctrl-C Behavior Options ==="
+    puts
+    puts "1. :clear_prompt (default)"
+    puts "   - Shows ^C and hint message"
+    puts "   - Clear and friendly"
+    
+    puts "\n2. :show_help"
+    puts "   - Shows help reminder"
+    puts "   - Good for new users"
+    
+    puts "\n3. :silent"
+    puts "   - Just clears the line"
+    puts "   - Minimal interruption"
+    
+    puts "\nYou can configure with:"
+    puts "  configure_interactive(ctrl_c_behavior: :show_help)"
+  end
+  
+  desc "test_clear", "Test with clear_prompt behavior"
+  def test_clear
+    puts "Starting new shell with :clear_prompt behavior"
+    puts "Try pressing Ctrl-C..."
+    puts
+    
+    SignalDemo.new.interactive
+  end
+  
+  desc "test_help", "Test with show_help behavior"
+  def test_help
+    puts "Starting new shell with :show_help behavior"
+    puts "Try pressing Ctrl-C..."
+    puts
+    
+    test_app = Class.new(Thor) do
+      include Thor::Interactive::Command
+      configure_interactive(
+        prompt: "help> ",
+        ctrl_c_behavior: :show_help
+      )
+      
+      desc "test", "Test command"
+      def test
+        puts "Test executed"
+      end
+    end
+    
+    test_app.new.interactive
+  end
+  
+  desc "test_silent", "Test with silent behavior"
+  def test_silent
+    puts "Starting new shell with :silent behavior"
+    puts "Try pressing Ctrl-C..."
+    puts
+    
+    test_app = Class.new(Thor) do
+      include Thor::Interactive::Command
+      configure_interactive(
+        prompt: "silent> ",
+        ctrl_c_behavior: :silent
+      )
+      
+      desc "test", "Test command"
+      def test
+        puts "Test executed"
+      end
+    end
+    
+    test_app.new.interactive
+  end
+  
+  desc "help_signals", "Explain signal handling"
+  def help_signals
+    puts <<~HELP
+    
+    === Signal Handling in thor-interactive ===
+    
+    CTRL-C (SIGINT):
+      Single Press:
+        - Clears current input line
+        - Shows hint about double Ctrl-C
+        - Returns to fresh prompt
+        
+      Double Press (within 500ms):
+        - Exits the interactive shell
+        - Same as typing 'exit'
+    
+    CTRL-D (EOF):
+      - Exits immediately
+      - Standard Unix EOF behavior
+      - Same as typing 'exit'
+    
+    EXIT COMMANDS:
+      - exit
+      - quit  
+      - q
+      - /exit, /quit, /q (with slash)
+    
+    CONFIGURATION:
+      configure_interactive(
+        ctrl_c_behavior: :clear_prompt,  # or :show_help, :silent
+        double_ctrl_c_timeout: 0.5        # seconds
+      )
+    
+    BEHAVIOR OPTIONS:
+      :clear_prompt (default)
+        Shows "^C" and hint message
+        
+      :show_help
+        Shows help reminder on Ctrl-C
+        
+      :silent
+        Just clears the line, no message
+    
+    WHY THIS DESIGN?
+      - Matches behavior of Python, Node.js REPLs
+      - Prevents accidental exit
+      - Clear feedback to user
+      - Configurable for different preferences
+    
+    HELP
+  end
+  
+  default_task :help_signals
+end
+
+if __FILE__ == $0
+  puts "Signal Handling Demo"
+  puts "==================="
+  puts
+  puts "Try these:"
+  puts "  1. Press Ctrl-C once (clears prompt)"
+  puts "  2. Press Ctrl-C twice quickly (exits)"
+  puts "  3. Press Ctrl-D (exits immediately)"
+  puts "  4. Type 'exit', 'quit', or 'q' (exits)"
+  puts
+  puts "Starting interactive shell..."
+  puts
+  
+  SignalDemo.new.interactive
+end

lib/thor/interactive/shell.rb

@@ -29,6 +29,12 @@ def initialize(thor_class, options = {})
         @prompt = merged_options[:prompt] || DEFAULT_PROMPT
         @history_file = File.expand_path(merged_options[:history_file] || DEFAULT_HISTORY_FILE)
 
+        # Ctrl-C handling configuration
+        @ctrl_c_behavior = merged_options[:ctrl_c_behavior] || :clear_prompt
+        @double_ctrl_c_timeout = merged_options.key?(:double_ctrl_c_timeout) ? 
+                                merged_options[:double_ctrl_c_timeout] : 0.5
+        @last_interrupt_time = nil
+        
         setup_completion
         load_history
       end
@@ -56,27 +62,36 @@ def start
         puts "(Debug: Entering main loop)" if ENV["DEBUG"]
 
         loop do
-          line = Reline.readline(display_prompt, true)
-          puts "(Debug: Got input: #{line.inspect})" if ENV["DEBUG"]
-          
-          if should_exit?(line)
-            puts "(Debug: Exit condition met)" if ENV["DEBUG"]
-            break
-          end
-          
-          next if line.nil? || line.strip.empty?
-          
           begin
+            line = Reline.readline(display_prompt, true)
+            puts "(Debug: Got input: #{line.inspect})" if ENV["DEBUG"]
+            
+            # Reset interrupt tracking on successful input
+            @last_interrupt_time = nil if line
+            
+            if should_exit?(line)
+              puts "(Debug: Exit condition met)" if ENV["DEBUG"]
+              break
+            end
+            
+            next if line.nil? || line.strip.empty?
+            
             puts "(Debug: Processing input: #{line.strip})" if ENV["DEBUG"]
             process_input(line.strip)
             puts "(Debug: Input processed successfully)" if ENV["DEBUG"]
+            
           rescue Interrupt
-            puts "\n(Interrupted - press Ctrl+D or type 'exit' to quit)"
+            # Handle Ctrl-C
+            if handle_interrupt
+              break  # Exit on double Ctrl-C
+            end
+            next  # Continue on single Ctrl-C
+            
           rescue SystemExit => e
             puts "A command tried to exit with code #{e.status}. Staying in interactive mode."
             puts "(Debug: SystemExit caught in main loop)" if ENV["DEBUG"]
           rescue => e
-            puts "Error in main loop: #{e.message}"
+            puts "Error: #{e.message}"
             puts e.backtrace.first(5) if ENV["DEBUG"]
             puts "(Debug: Error handled, continuing loop)" if ENV["DEBUG"]
             # Continue the loop - don't let errors break the session
@@ -343,6 +358,37 @@ def should_exit?(line)
         # Handle both /exit and exit for convenience
         EXIT_COMMANDS.include?(stripped) || EXIT_COMMANDS.include?(stripped.sub(/^\//, ''))
       end
+      
+      def handle_interrupt
+        current_time = Time.now
+        
+        # Check for double Ctrl-C
+        if @last_interrupt_time && @double_ctrl_c_timeout && (current_time - @last_interrupt_time) < @double_ctrl_c_timeout
+          puts "\n(Interrupted twice - exiting)"
+          @last_interrupt_time = nil  # Reset for next time
+          return true  # Signal to exit
+        end
+        
+        @last_interrupt_time = current_time
+        
+        # Single Ctrl-C behavior
+        case @ctrl_c_behavior
+        when :clear_prompt
+          puts "^C"
+          puts "(Press Ctrl-C again quickly or Ctrl-D to exit)"
+        when :show_help
+          puts "\n^C - Interrupt"
+          puts "Press Ctrl-C again to exit, or type 'help' for commands"
+        when :silent
+          # Just clear the line, no message
+          print "\r#{' ' * 80}\r"
+        else
+          # Default behavior
+          puts "^C"
+        end
+        
+        false  # Don't exit, just clear prompt
+      end
 
       def show_welcome(nesting_level = 0)
         if nesting_level > 0

lib/thor/interactive/version_constant.rb

@@ -4,5 +4,5 @@
 # This file is separate to avoid circular dependencies during gem installation
 
 module ThorInteractive
-  VERSION = "0.1.0.pre.2"
-end
+  VERSION = "0.1.0.pre.3"
+end