[Feature Idea] Output Streaming

[albertalef]

Problem: Long-running commands block until completion; no way to see progress.

Solution: Add callbacks for real-time output processing.

# Stream output as it arrives
sh do
  make("build", _on_stdout: ->(chunk) { print chunk })
end

# Progress tracking
lines_processed = 0
sh do
  find(".", name: "*.log", _on_stdout: ->(chunk) {
    lines_processed += chunk.count("\n")
    print "\rProcessed #{lines_processed} files..."
  })
end
puts "\nDone!"

# Early termination
sh do
  tail("-f", "app.log", _on_stdout: ->(chunk) {
    raise StopIteration if chunk.include?("ERROR")
    print chunk
  })
end

Variants

make("build", _on_stdout: ->(chunk) { print chunk })

make("build", _on: { stdout: ->(chunk) { print chunk }})

make!("build").on_stdout do |chunk|
  print chunk
end.exec

make!("build").on_stdout do |chunk|
  print chunk
end.on_stderr do |chunk|
  print chunk
end.exec

make!("build").on(:stdout) do |chunk|
  print chunk
end.exec

Implementation:

• Modify TerminalExecutor.capture to yield chunks during IO.select loop
• Support _on_stdout, _on_stderr, _on_output (both) callbacks
• Handle StopIteration for early termination