Class: IO

Inherits:
Object
  • Object
show all
Defined in:
lib/tlspretense/ext_core/io_raw_input.rb

Overview

Extends IO to enable “raw” input on TTYs.

Instance Method Summary collapse

Instance Method Details

#disable_raw_chars ⇒ Object

Reverts the termios state to what it was before calling #enable_raw_chars.

Raises:

  • (IOError) 


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# File 'lib/tlspretense/ext_core/io_raw_input.rb', line 25

def disable_raw_chars
  raise IOError, "#{self} is not a TTY." unless self.tty?
  Termios.tcsetattr(self, Termios::TCSANOW, @_oldtermios)
end

#enable_raw_chars ⇒ Object

Enables raw character input for a TTY. It uses the ruby-termios gem to disable ICANON and ECHO functionality. This means that characters will become immediately available to IO#gets, IO#getchar, etc. after the user presses a button, and that the characters will not be implicitly echoed to the screen.

If you call this on $stdin, you probably should ensure that you call #disable_raw_chars in order to restore the previous termios state after your program exits. Otherwise, you may screw up the user’s terminal, and they will have to call reset.

Raises:

  • (IOError) 


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# File 'lib/tlspretense/ext_core/io_raw_input.rb', line 15

def enable_raw_chars
  raise IOError, "#{self} is not a TTY." unless self.tty?
  @_oldtermios = Termios.tcgetattr(self)
  newt = @_oldtermios.dup
  newt.c_lflag &= ~Termios::ICANON
  newt.c_lflag &= ~Termios::ECHO
  Termios.tcsetattr(self, Termios::TCSANOW, newt)
end