#!perl

use strict;
use warnings;
use Getopt::Long;

our $AUTHORITY = 'cpan:PERLANCAR'; # AUTHORITY
our $DATE = '2024-02-01'; # DATE
our $DIST = 'App-linenum'; # DIST
our $VERSION = '0.002'; # VERSION

my %Opts = (
    format         => '%4d|',
    # XXX whether to add line number to empty lines
    # XXX starting line number
    # XXX line number increment (default 1)
);

sub parse_cmdline {
    my $res = GetOptions(
        'format|f=s'     => \$Opts{format},
        'ordered|o'            => sub { $Opts{format} = '%d. ' },
        'unordered-dash|d'     => sub { $Opts{format} = '- ' },
        'unordered-asterisk|a' => sub { $Opts{format} = '* ' },
        'version|v'      => sub {
            no warnings 'once';
            print "linenum version ", ($main::VERSION || "dev"), "\n";
            exit 0;
        },
        'help|h'           => sub {
            print <<USAGE;
Usage:
  linenum [OPTIONS]... [FILE]...
  linenum --version (or -v)
  linenum --help (or -h)
Options:
  --format, -f
  --ordered, -o  (shortcut for --format "%d. ")
  --unordered-dash, -d  (shortcut for --format "- ")

For more details, see the manpage/documentation.
USAGE
            exit 0;
        },
    );
    exit 99 if !$res;
}

sub run {
    my $i = 0;
    while (<>) {
        $i++;
        my $linum;
        no warnings 'redundant';
        if (/\S/) {
            $linum = sprintf $Opts{format}, $i;
        } else {
            $linum = sprintf $Opts{format}, $i;
            $linum =~ s/(-?[0-9]+)/" " x length($1)/e;
        }
        print $linum, $_;
    }
}

# MAIN

parse_cmdline();
run();

1;
# ABSTRACT: Add line number to lines
# PODNAME: linenum

__END__

=pod

=encoding UTF-8

=head1 NAME

linenum - Add line number to lines

=head1 VERSION

This document describes version 0.002 of linenum (from Perl distribution App-linenum), released on 2024-02-01.

=head1 SYNOPSIS

 linenum [OPTION]... [FILE]...

=head1 DESCRIPTION

=head1 HOMEPAGE

Please visit the project's homepage at L<https://metacpan.org/release/App-linenum>.

=head1 SOURCE

Source repository is at L<https://github.com/perlancar/perl-App-linenum>.

=head1 SEE ALSO

L<String::LineNumber>

=head1 AUTHOR

perlancar <perlancar@cpan.org>

=head1 CONTRIBUTING


To contribute, you can send patches by email/via RT, or send pull requests on
GitHub.

Most of the time, you don't need to build the distribution yourself. You can
simply modify the code, then test via:

 % prove -l

If you want to build the distribution (e.g. to try to install it locally on your
system), you can install L<Dist::Zilla>,
L<Dist::Zilla::PluginBundle::Author::PERLANCAR>,
L<Pod::Weaver::PluginBundle::Author::PERLANCAR>, and sometimes one or two other
Dist::Zilla- and/or Pod::Weaver plugins. Any additional steps required beyond
that are considered a bug and can be reported to me.

=head1 COPYRIGHT AND LICENSE

This software is copyright (c) 2024, 2018 by perlancar <perlancar@cpan.org>.

This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.

=head1 BUGS

Please report any bugs or feature requests on the bugtracker website L<https://rt.cpan.org/Public/Dist/Display.html?Name=App-linenum>

When submitting a bug or request, please include a test-file or a
patch to an existing test-file that illustrates the bug or desired
feature.

=cut
