Fork

Forks a new child process.

• In the child process, 0 will be returned.
• In the parent process, the child process'es PID will be returned.

if (pid = Fork.fork) == 0
  # in the child process
else
  # in the parent process
end

Forks a new child process.

• In the child process, the given block will be called.
• In the parent process, the process will wait for the child process to exit and return the child process'es exit status.

status = Fork.fork do
  # in the child process
end

puts "Child process exited with #{status.exit_status}"

Waits for any child to exit and retuns the exit status.

Raises an Error exception if the wait(2) syscall returned -1.

Waits for a specific child process to exit and rturns the exit status.

Raises an Error exception if the waitpid(2) syscall returned -1.