in reply to Re: how to check for keyboard input
in thread how to check for keyboard input

Warning: you need to set the readmode back to normal before exiting. So don't just exit on 'q' - do something to get the terminal back into its regular state.

sub safe_exit {
  ReadMode('normal');
  exit(@_);
}

# ...
   safe_exit if $key eq 'q';
# ...

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Re^3: how to check for keyboard input
by chb (Deacon) on Jul 21, 2005 at 08:07 UTC
    To be extra sure the terminal is in a sane state after the program exits, the safe_exit routine could be hooked in some other places, too, e.g. 
    $SIG{'INT'} = \&safe_exit;
$SIG{'QUIT'} = \&safe_exit;
$SIG{__DIE__} = \&safe_exit;
END { safe_exit(); }

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    --- Update: oops, references added, as benizi pointed out below
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      s/&/\\&/g; Otherwise, safe_exit is immediately called. Also, I tend to wrap sub's similar to safe_exit in lexical blocks and prevent them from being called more than once. e.g.

      use Term::ReadKey;
{
    my $called = 0;
    sub safe_exit {
        print "safe_exit called $called times before\n";
        return if $called++;
        # disconnect from DB, etc. (things that should only be done on
+ce)
        ReadMode 'normal';
        print "Exiting safely\n";
        print "exit(@_)\n" if @_;
        exit @_;
    }
}
$SIG{$_} = \&safe_exit for qw/INT QUIT __DIE__/;
END { safe_exit(); }

ReadMode 'cbreak';
print "Entering loop. Try: kill -INT $$, to see that I exit safely.\nH
+it 'x' to see me die.\n";
while (1) {
    next unless defined(my $key = ReadKey);
    print "In the loop, got: $key\n";
    last if $key eq 'q';
    die "with this error message" if $key eq 'x';
}

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