PTY

Creates and managed pseudo terminals (PTYs). See also http://en.wikipedia.org/wiki/Pseudo_terminal

PTY allows you to allocate new terminals using ::open or ::spawn a new terminal with a specific command.

Example

In this example we will change the buffering type in the factor command, assuming that factor uses stdio for stdout buffering.

If IO.pipe is used instead of PTY.open, this code deadlocks because factor’s stdout is fully buffered.

# start by requiring the standard library PTY
require 'pty'

master, slave = PTY.open
read, write = IO.pipe
pid = spawn("factor", :in=>read, :out=>slave)
read.close     # we dont need the read
slave.close    # or the slave

# pipe "42" to the factor command
write.puts "42"
# output the response from factor
p master.gets #=> "42: 2 3 7\n"

# pipe "144" to factor and print out the response
write.puts "144"
p master.gets #=> "144: 2 2 2 2 3 3\n"
write.close # close the pipe

# The result of read operation when pty slave is closed is platform
# dependent.
ret = begin
        master.gets     # FreeBSD returns nil.
      rescue Errno::EIO # GNU/Linux raises EIO.
        nil
      end
p ret #=> nil

License

C) Copyright 1998 by Akinori Ito.

This software may be redistributed freely for this purpose, in full
or in part, provided that this entire copyright notice is included
on any copies of this software and applications and derivations thereof.

This software is provided on an "as is" basis, without warranty of any
kind, either expressed or implied, as to any matter including, but not
limited to warranty of fitness of purpose, or merchantability, or
results obtained from use of this software.