65 lines
1.5 KiB
Ruby
65 lines
1.5 KiB
Ruby
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class IO
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def discard_input
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icanon = false
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if tty?
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begin
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# With Ruby 1.9.3, simply call IO#iflush.
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require 'io/console'
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return iflush
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rescue LoadError
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# Try to run stty(1) to check if this terminal uses
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# canonical input mode. Acts like `stty -a`, but redirects
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# stdin from tty. Works with Ruby 1.8, no Process#spawn.
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r, w, pid = nil
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begin
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r, w = IO.pipe
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pid = fork do
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IO.for_fd(0).reopen(self) # stdin from tty
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IO.for_fd(1).reopen(w) # stdout to pipe
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exec 'stty', '-a'
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end
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w.close; w = nil
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icanon = (not r.read.include? "-icanon")
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rescue
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# stty(1) only works with Unix clones.
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ensure
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pid and Process.wait pid
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w and w.close
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r and r.close
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end
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end
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end
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if icanon
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# Turn off canonical input mode.
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pid = nil
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begin
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pid = fork do
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IO.for_fd(0).reopen(self) # stdin from tty
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exec 'stty', '-icanon'
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end
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ensure
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pid and Process.wait pid
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end
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end
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# Discard input.
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loop { $stdin.read_nonblock(256) } rescue nil
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if icanon
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# Turn on canonical input mode.
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pid = nil
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begin
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pid = fork do
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IO.for_fd(0).reopen(self) # stdin from tty
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exec 'stty', 'icanon'
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end
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ensure
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pid and Process.wait pid
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end
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end
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nil
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end
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end
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