make "perl -c script/re.pl" not start up the REPL

[p5sagit/Devel-REPL.git] / lib / Devel / REPL / Plugin / Interrupt.pm

use strict;
use warnings;
package Devel::REPL::Plugin::Interrupt;

use Devel::REPL::Plugin;
use Sys::SigAction qw(set_sig_handler);
use namespace::autoclean;

around 'run' => sub {
    my ($orig, $self) = (shift, shift);

    local $SIG{INT} = 'IGNORE';

    return $self->$orig(@_);
};

around 'run_once' => sub {
    my ($orig, $self) = (shift, shift);

    # We have to use Sys::SigAction: Perl 5.8+ has safe signal handling by
    # default, and Term::ReadLine::Gnu restarts the interrupted system calls.
    # The result is that the signal handler is not fired until you hit Enter.
    my $sig_action = set_sig_handler INT => sub {
        die "Interrupted.\n";
    };

    return $self->$orig(@_);
};

around 'read' => sub {
    my ($orig, $self) = (shift, shift);

    # here SIGINT is caught and only kills the line being edited
    while (1) {
        my $line = eval { $self->$orig(@_) };
        return $line unless $@;

        die unless $@ =~ /^Interrupted\./;

        # (Term::ReadLine::Gnu kills the line by default, but needs a LF -
        # maybe I missed something?)
        print "\n";
    }
};

1;

__END__

=head1 NAME

Devel::REPL::Plugin::Interrupt - traps SIGINT to kill long-running lines

=head1 DESCRIPTION

By default L<Devel::REPL> exits on SIGINT (usually Ctrl-C). If you load this
module, SIGINT will be trapped and used to kill long-running commands
(statements) and also to kill the line being edited (like eg. BASH do). (You
can still use Ctrl-D to exit.)

=head1 AUTHOR

Shawn M Moore, C<< <sartak at gmail dot com> >>

=cut