view release on metacpan or  search on metacpan

lib/Devel/Probe.pm  view on Meta::CPAN

    my %config = (
        actions => [
            { action => 'define', file => __FILE__, lines => [ 22 ] },
            { action => 'define', file => __FILE__, type => Devel::Probe::PERMANENT, lines => [ 23 ] },
        ],
    );
    Devel::Probe::config(\%config);
    Devel::Probe::enable();
    my $count;
    while (1) {
        $count++;                                   # line 22
        my $something_inside_the_loop = $count * 2; # line 23
        sleep 5;
    }
    Devel::Probe::disable();

As another example, you can pass a custom argument to the trigger callback:

    # line 1
    use 5.18.0;
    use PadWalker qw(peek_my);
    use Devel::Probe;

    Devel::Probe::trigger(sub {
        my ($file, $line, $interesting_var_name) = @_;
        say "$interesting_var_name: " . ${ peek_my(1)->{$interesting_var_name} };
    });

    my %config = (
        actions => [
            { action => 'enable' },
            { action => 'define',
              file => __FILE__,
              type => Devel::Probe::PERMANENT,
              lines => [ 26 ],
              argument => '$squared'
            },
        ],
    );
    Devel::Probe::config(\%config);
    my $count = 0;
    my $squared = 0;
    while (1) {
        $count++;
        $squared = $count * $count; # line 26
        sleep 5;
    }

=head1 SUGGESTIONS

For files found directly by the Perl interpreter, the file name in the probe
definition will usually be a relative path name; for files that are found
through the PERL5LIB environment variable, the file name in the probe
definition will usually be a full path name.

One typical use case would be to have a signal handler associated with a
specific signal, which when triggered would disable the module, read the
configuration from a given place, reconfigure the module accordingly and then
enable it.  Similarly, this kind of control can be implemented using remote
endpoints to deal with reconfiguring, disabling and enabling the module.

=head1 TODO

=over 4

=item

Probes are stored in a hash of file names; per file name, there is a hash
of line numbers (with the probe type as a value).  It is likely this can be
made more performant with a better data structure, but that needs profiling.

=back

=head1 AUTHORS

=over 4

=item * Gonzalo Diethelm C<< gonzus AT cpan DOT org >>

=item * Ben Tyler C<< btyler AT cpan DOT org >>

=back