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lib/App/Timestamper.pm  view on Meta::CPAN

use App::Timestamper::Filter::TS;

sub new
{
    my $class = shift;

    my $self = bless {}, $class;

    $self->_init(@_);

    return $self;
}

sub _init
{
    my ( $self, $args ) = @_;

    my $argv = [ @{ $args->{argv} } ];

    my $help    = 0;
    my $man     = 0;
    my $version = 0;
    if (
        !(
            my $ret = GetOptionsFromArray(
                $argv,
                'help|h' => \$help,
                man      => \$man,
                version  => \$version,
            )
        )
        )
    {
        die "GetOptions failed!";
    }

    if ($help)
    {
        pod2usage(1);
    }

    if ($man)
    {
        pod2usage( -verbose => 2 );
    }

    if ($version)
    {
        print "timestamper version $App::Timestamper::VERSION .\n";
        exit(0);
    }

    $self->{_argv} = $argv;
}

sub run
{
    my ($self) = @_;

    local @ARGV = @{ $self->{_argv} };
    STDOUT->autoflush(1);

    App::Timestamper::Filter::TS->new->fh_filter( \*ARGV,
        sub { print $_[0]; } );

    return;
}

1;

__END__

=pod

=encoding UTF-8

=head1 NAME

App::Timestamper - prefix lines with the timestamps of their arrivals.

=head1 VERSION

version 0.2.1

=head1 SYNOPSIS

    use App::Timestamper;

    App::Timestamper->new({ argv => [@ARGV] })->run();

=head1 DESCRIPTION

App::Timestamper is a pure-Perl command line program that filters the input
so the timestamps (in seconds+fractions since the UNIX epoch) are prefixed
to the lines based on the time of the arrival.

So if the input was something like:

    First Line
    Second Line
    Third Line

It will become something like:

    1435254285.978485482\tFirst Line
    1435254302.569615087\tSecond Line
    1435254319.809459781\tThird Line

=head2 Some use cases

Some people asked me what is B<timestamper> useful for, so I'll try to
explain because I wrote the first version out of a need.

Let's suppose you have a simulation that outputs a "Reached $N iterations"
line after every certain number of iterations. Like so:

    Reached 100000 iterations
    Reached 200000 iterations
    Reached 300000 iterations
    .