Skip to content
Kward Search API index

Class: Kward::PersistentShellSession

Inherits:
Object
  • Object
show all
Defined in:
lib/kward/persistent_shell_session.rb

Overview

Owns one interactive shell process and serializes user and agent commands.

The process is kept alive between commands so shell variables, functions, aliases, directory changes, and child-shell state belong to one session.

Defined Under Namespace

Classes: CommandInterrupted, InteractiveResult

Constant Summary collapse

Result = 
Kwsh::Result
READ_SIZE = 
4_096
STARTUP_TIMEOUT_SECONDS = 
5
STTY_COMMAND = 
if File.executable?("/bin/stty")
  "/bin/stty"
elsif File.executable?("/usr/bin/stty")
  "/usr/bin/stty"
else
  "stty"
end.freeze
STATEFUL_COMMANDS = 
%w[alias cd export pwd unset unalias].freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(cwd: Dir.pwd, env: ENV.to_h, shell: Kwsh::DEFAULT_SHELL, configured_env: {}, aliases: {}, timeout_seconds: Kwsh::DEFAULT_TIMEOUT_SECONDS, max_output_bytes: Kwsh::DEFAULT_MAX_OUTPUT_BYTES, window_size_provider: nil) ⇒ PersistentShellSession

Returns a new instance of PersistentShellSession.



43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
 
# File 'lib/kward/persistent_shell_session.rb', line 43

def initialize(cwd: Dir.pwd, env: ENV.to_h, shell: Kwsh::DEFAULT_SHELL, configured_env: {}, aliases: {}, timeout_seconds: Kwsh::DEFAULT_TIMEOUT_SECONDS, max_output_bytes: Kwsh::DEFAULT_MAX_OUTPUT_BYTES, window_size_provider: nil)
  @cwd = File.expand_path(cwd.to_s.empty? ? Dir.pwd : cwd.to_s)
  @base_env = env.to_h.transform_keys(&:to_s).transform_values(&:to_s)
  @configured_env = configured_env.to_h.transform_keys(&:to_s).transform_values(&:to_s)
  @aliases = aliases.to_h.transform_keys(&:to_s).transform_values(&:to_s)
  @shell = shell.to_s.empty? ? Kwsh::DEFAULT_SHELL : shell.to_s
  @timeout_seconds = timeout_seconds.to_i.positive? ? timeout_seconds.to_i : Kwsh::DEFAULT_TIMEOUT_SECONDS
  @max_output_bytes = max_output_bytes.to_i.positive? ? max_output_bytes.to_i : Kwsh::DEFAULT_MAX_OUTPUT_BYTES
  @window_size_provider = window_size_provider
  @last_command = nil
  @last_result = nil
  @command_mutex = Mutex.new
  @write_mutex = Mutex.new
  @marker_counter = 0
  @marker_prefix = "__KWARD_SHELL_#{SecureRandom.hex(16)}_"
  @closed = false
  @routing_shell = build_routing_shell
  @env = @routing_shell.child_env

  start_process
  initialize_protocol
rescue StandardError
  close
  raise
end

Instance Attribute Details

#cwd ⇒ Object (readonly)

Returns the value of attribute cwd.



41
42
43
 
# File 'lib/kward/persistent_shell_session.rb', line 41

def cwd
  @cwd
end

#last_command ⇒ Object (readonly)

Returns the value of attribute last_command.



41
42
43
 
# File 'lib/kward/persistent_shell_session.rb', line 41

def last_command
  @last_command
end

#timeout_seconds ⇒ Object (readonly)

Returns the value of attribute timeout_seconds.



41
42
43
 
# File 'lib/kward/persistent_shell_session.rb', line 41

def timeout_seconds
  @timeout_seconds
end

Instance Method Details

#child_env(interactive: false) ⇒ Object 



73
74
75
 
# File 'lib/kward/persistent_shell_session.rb', line 73

def child_env(interactive: false)
  @env.dup
end

#close ⇒ Object 



180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
 
# File 'lib/kward/persistent_shell_session.rb', line 180

def close
  return if @closed

  @closed = true
  begin
    terminate_process_group(@pid) if @pid
  ensure
    @write_mutex.synchronize do
      @reader&.close unless @reader&.closed?
      @writer&.close unless @writer&.closed?
    end
    @process_thread&.join(0.5)
    @process_thread&.kill if @process_thread&.alive?
    @pid = nil
  end
rescue StandardError
  nil
end

#command_shell ⇒ Object 



69
70
71
 
# File 'lib/kward/persistent_shell_session.rb', line 69

def command_shell
  @shell
end

#complete(input, cursor) ⇒ Object 



168
169
170
 
# File 'lib/kward/persistent_shell_session.rb', line 168

def complete(input, cursor)
  completion_shell.complete(input, cursor)
end

#context_snapshot(max_output_bytes: Kwsh::CONTEXT_OUTPUT_BYTES) ⇒ Object

Returns bounded shell state for an explicit shell-agent prompt.



159
160
161
162
163
164
165
166
 
# File 'lib/kward/persistent_shell_session.rb', line 159

def context_snapshot(max_output_bytes: Kwsh::CONTEXT_OUTPUT_BYTES)
  {
    cwd: @cwd,
    last_command: @last_command,
    exit_status: @last_result&.exit_status,
    last_output: context_output(@last_result&.output, max_output_bytes)
  }
end

#editor_command_result(command, display_command: command) ⇒ Object 



176
177
178
 
# File 'lib/kward/persistent_shell_session.rb', line 176

def editor_command_result(command, display_command: command)
  @routing_shell.editor_command_result(command, display_command: display_command)
end

#expand_alias(command, interactive: false) ⇒ Object 



172
173
174
 
# File 'lib/kward/persistent_shell_session.rb', line 172

def expand_alias(command, interactive: false)
  @routing_shell.expand_alias(command, interactive: interactive)
end

#prompt_label ⇒ Object 



77
78
79
 
# File 'lib/kward/persistent_shell_session.rb', line 77

def prompt_label
  "Shell #{display_cwd} $"
end

#record_interactive_result(output:, exit_status:) ⇒ Object

Records the safe output captured after an interactive terminal handoff.



152
153
154
155
156
 
# File 'lib/kward/persistent_shell_session.rb', line 152

def record_interactive_result(output:, exit_status:)
  return unless @last_command

  @last_result = Result.new(output: ANSI.sanitize_transcript(output.to_s), exit_status: exit_status)
end

#run(input, cancellation: nil, &block) ⇒ Object 



81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
 
# File 'lib/kward/persistent_shell_session.rb', line 81

def run(input, cancellation: nil, &block)
  command = input.to_s.strip
  return Result.new(output: "", exit_status: 0) if command.empty?

  expanded_command = expand_alias(command)
  words = shell_words(expanded_command)
  sync_runtime_state(words)
  result = if words.empty?
    Result.new(output: "", exit_status: 0)
  elsif words.first == "clear"
    Result.new(output: "", exit_status: 0, clear: true)
  elsif %w[exit logout].include?(words.first)
    exit_result(command, words)
  elsif words.first == "capture"
    capture_result(command, expanded_command, cancellation: cancellation, &block)
  elsif words.first == "pty"
    interactive_result(command, expanded_command)
  elsif %w[source .].include?(words.first)
    source_result(command, words)
  elsif (editor_result = editor_command_result(command))
    editor_result
  elsif stateful_command?(words)
    execute_command(expanded_command, display_command: command, cancellation: cancellation, &block)
  else
    Result.new(output: command_echo(command), exit_status: 0, interactive_command: expanded_command)
  end
  remember_result(command, result)
  result
rescue ArgumentError => e
  result = Result.new(output: "#{command_echo(command)}kwsh: #{e.message}\n", exit_status: 2)
  remember_result(command, result)
  result
end

#run_for_agent(input, timeout_seconds: nil, cancellation: nil) ⇒ Object

Runs a command for the shell assistant without handing it the terminal.



116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
 
# File 'lib/kward/persistent_shell_session.rb', line 116

def run_for_agent(input, timeout_seconds: nil, cancellation: nil)
  command = input.to_s.strip
  return run(command, cancellation: cancellation) if command.empty?

  result = run(command, cancellation: cancellation)
  return result unless result.interactive_command

  result = execute_command(
    result.interactive_command,
    display_command: command,
    timeout_seconds: timeout_seconds,
    cancellation: cancellation,
    suppress_git_pager: true
  )
  remember_result(command, result)
  result
end

#run_interactive(command, input:, sink:, tab_action_handler: nil, on_detach: nil) ⇒ Object

Runs an external command through the same persistent shell process while the caller owns the terminal.



136
137
138
139
140
141
142
143
144
145
146
147
148
149
 
# File 'lib/kward/persistent_shell_session.rb', line 136

def run_interactive(command, input:, sink:, tab_action_handler: nil, on_detach: nil)
  protocol = with_raw_input(input) do
    execute_protocol(command, input: input, sink: sink, tab_action_handler: tab_action_handler, on_detach: on_detach)
  end
  update_cwd(protocol[:cwd]) unless protocol[:background]
  InteractiveResult.new(
    exit_status: protocol[:status] || 1,
    input_forwarded: protocol[:input_forwarded],
    tab_action: protocol[:tab_action],
    background: protocol[:background]
  )
ensure
  sink.finish if sink.respond_to?(:finish)
end