#!/usr/bin/env perl
#
# This file, ack, is generated code.
# Please DO NOT EDIT or send patches for it.
#
# Please take a look at the source from
# https://github.com/beyondgrep/ack3
# and submit patches against the individual files
# that build ack.
#

$App::Ack::STANDALONE = 1;
package main;

use strict;
use warnings;
our $VERSION = '2.999_01'; # Check https://beyondgrep.com/ for updates

use 5.010001;
use Getopt::Long 2.38 ();
use Carp 1.04 ();

use File::Spec ();



# Global command-line options
our $opt_after_context;
our $opt_before_context;
our $opt_break;
our $opt_color;
our $opt_column;
our $opt_count;
our $opt_f;
our $opt_g;
our $opt_heading;
our $opt_L;
our $opt_l;
our $opt_lines;
our $opt_m;
our $opt_output;
our $opt_passthru;
our $opt_print0;
our $opt_proximate;
our $opt_regex;
our $opt_show_filename;
our $opt_u;
our $opt_v;

# Flag if we need any context tracking.
our $is_tracking_context;

our @special_vars_used_by_opt_output;
our $special_vars_used_by_opt_output;

MAIN: {
    $App::Ack::ORIGINAL_PROGRAM_NAME = $0;
    $0 = join(' ', 'ack', $0);
    if ( $App::Ack::VERSION ne $main::VERSION ) {
        App::Ack::die( "Program/library version mismatch\n\t$0 is $main::VERSION\n\t$INC{'App/Ack.pm'} is $App::Ack::VERSION" );
    }

    # Do preliminary arg checking;
    my $env_is_usable = 1;
    for my $arg ( @ARGV ) {
        last if ( $arg eq '--' );

        # Get the --thpppt, --bar, --cathy checking out of the way.
        $arg =~ /^--th[pt]+t+$/ and App::Ack::thpppt($arg);
        $arg eq '--bar'         and App::Ack::ackbar();
        $arg eq '--cathy'       and App::Ack::cathy();

        # See if we want to ignore the environment. (Don't tell Al Gore.)
        $arg eq '--env'         and $env_is_usable = 1;
        $arg eq '--noenv'       and $env_is_usable = 0;
    }

    if ( !$env_is_usable ) {
        my @keys = ( 'ACKRC', grep { /^ACK_/ } keys %ENV );
        delete @ENV{@keys};
    }

    # Load colors
    my $modules_loaded_ok = eval 'use Term::ANSIColor 1.10 (); 1;';
    if ( $modules_loaded_ok && $App::Ack::is_windows ) {
        $modules_loaded_ok = eval 'use Win32::Console::ANSI; 1;';
    }
    if ( $modules_loaded_ok ) {
        $ENV{ACK_COLOR_MATCH}    ||= 'black on_yellow';
        $ENV{ACK_COLOR_FILENAME} ||= 'bold green';
        $ENV{ACK_COLOR_LINENO}   ||= 'bold yellow';
        $ENV{ACK_COLOR_COLNO}    ||= 'bold yellow';
    }

    Getopt::Long::Configure('default', 'no_auto_help', 'no_auto_version');
    Getopt::Long::Configure('pass_through', 'no_auto_abbrev');
    Getopt::Long::GetOptions(
        'help'       => sub { App::Ack::show_help(); exit; },
        'version'    => sub { App::Ack::print( App::Ack::get_version_statement() ); exit; },
        'man'        => sub { App::Ack::show_docs( 'Manual' ); }, # man/faq/cookbook all exit.
        'faq'        => sub { App::Ack::show_docs( 'FAQ' ); },
        'cookbook'   => sub { App::Ack::show_docs( 'Cookbook' ); },
    );
    Getopt::Long::Configure('default', 'no_auto_help', 'no_auto_version');

    if ( !@ARGV ) {
        App::Ack::show_help();
        exit 1;
    }

    my @arg_sources = App::Ack::ConfigLoader::retrieve_arg_sources();

    my $opt = App::Ack::ConfigLoader::process_args( @arg_sources );

    $opt_after_context  = $opt->{after_context};
    $opt_before_context = $opt->{before_context};
    $opt_break          = $opt->{break};
    $opt_proximate      = $opt->{proximate};
    $opt_color          = $opt->{color};
    $opt_column         = $opt->{column};
    $opt_count          = $opt->{count};
    $opt_f              = $opt->{f};
    $opt_g              = $opt->{g};
    $opt_heading        = $opt->{heading};
    $opt_L              = $opt->{L};
    $opt_l              = $opt->{l};
    $opt_lines          = $opt->{lines};
    $opt_m              = $opt->{m};
    $opt_output         = $opt->{output};
    $opt_passthru       = $opt->{passthru};
    $opt_print0         = $opt->{print0};
    $opt_regex          = $opt->{regex};
    $opt_show_filename  = $opt->{show_filename};
    $opt_u              = $opt->{u};
    $opt_v              = $opt->{v};

    $App::Ack::report_bad_filenames = !$opt->{s};

    if ( !defined($opt_color) && !$opt_g ) {
        my $windows_color = 1;
        if ( $App::Ack::is_windows ) {
            $windows_color = eval { require Win32::Console::ANSI; };
        }
        $opt_color = !App::Ack::output_to_pipe() && $windows_color;
    }
    if ( not defined $opt_heading and not defined $opt_break  ) {
        $opt_heading = $opt_break = $opt->{break} = !App::Ack::output_to_pipe();
    }

    if ( defined($opt->{H}) || defined($opt->{h}) ) {
        $opt_show_filename = $opt->{show_filename} = $opt->{H} && !$opt->{h};
    }

    if ( defined $opt_output ) {
        # Expand out \t, \n and \r.
        $opt_output =~ s/\\n/\n/g;
        $opt_output =~ s/\\r/\r/g;
        $opt_output =~ s/\\t/\t/g;

        my @supported_special_variables = ( 1..9, qw( _ . ` & ' +  f ) );
        @special_vars_used_by_opt_output = grep { $opt_output =~ /\$$_/ } @supported_special_variables;
        $special_vars_used_by_opt_output = join( '', @special_vars_used_by_opt_output );

        # If the $opt_output contains $&, $` or $', those vars won't be
        # captured until they're used at least once in the program.
        # Do the eval to make this happen.
        for my $i ( @special_vars_used_by_opt_output ) {
            if ( $i eq q{&} || $i eq q{'} || $i eq q{`} ) {
                no warnings;    # They will be undef, so don't warn.
                eval qq{"\$$i"};
            }
        }
    }

    # Set up file filters.
    my $files;
    if ( $App::Ack::is_filter_mode && !$opt->{files_from} ) { # probably -x
        $files     = App::Ack::Files->from_stdin();
        $opt_regex = shift @ARGV if not defined $opt_regex;
        $opt_regex = $opt->{regex} = build_regex( $opt_regex, $opt );
    }
    else {
        if ( $opt_f || $opt_lines ) {
            # No need to check for regex, since mutex options are handled elsewhere.
        }
        else {
            $opt_regex = shift @ARGV if not defined $opt_regex;
            $opt_regex = $opt->{regex} = build_regex( $opt_regex, $opt );
        }
        if ( $opt_regex && $opt_regex =~ /\n/ ) {
            App::Ack::exit_from_ack( 0 );
        }
        my @start;
        if ( not defined $opt->{files_from} ) {
            @start = @ARGV;
        }
        if ( !exists($opt->{show_filename}) ) {
            unless(@start == 1 && !(-d $start[0])) {
                $opt_show_filename = $opt->{show_filename} = 1;
            }
        }

        if ( defined $opt->{files_from} ) {
            $files = App::Ack::Files->from_file( $opt, $opt->{files_from} );
            exit 1 unless $files;
        }
        else {
            @start = ('.') unless @start;
            foreach my $target (@start) {
                if ( !-e $target && $App::Ack::report_bad_filenames) {
                    App::Ack::warn( "$target: No such file or directory" );
                }
            }

            $opt->{file_filter}    = _compile_file_filter($opt, \@start);
            $opt->{descend_filter} = _compile_descend_filter($opt);

            $files = App::Ack::Files->from_argv( $opt, \@start );
        }
    }
    App::Ack::set_up_pager( $opt->{pager} ) if defined $opt->{pager};

    my $ors        = $opt_print0 ? "\0" : "\n";
    my $only_first = $opt->{1};

    my $nmatches    = 0;
    my $total_count = 0;

    set_up_line_context();

FILES:
    while ( my $file = $files->next ) {
        if ($is_tracking_context) {
            set_up_line_context_for_file();
        }

        # ack -f
        if ( $opt_f ) {
            if ( $opt->{show_types} ) {
                App::Ack::show_types( $file, $ors );
            }
            else {
                App::Ack::print( $file->name, $ors );
            }
            ++$nmatches;
            last FILES if defined($opt_m) && $nmatches >= $opt_m;
        }
        # ack -g
        elsif ( $opt_g ) {
            if ( $opt->{show_types} ) {
                App::Ack::show_types( $file, $ors );
            }
            else {
                local $opt_show_filename = 0; # XXX Why is this local?

                print_line_with_options( '', $file->name, 0, $ors );
            }
            ++$nmatches;
            last FILES if defined($opt_m) && $nmatches >= $opt_m;
        }
        # ack --lines
        elsif ( $opt_lines ) {
            my %line_numbers;
            foreach my $line ( @{ $opt_lines } ) {
                my @lines             = split /,/, $line;
                @lines                = map {
                    /^(\d+)-(\d+)$/
                        ? ( $1 .. $2 )
                        : $_
                } @lines;
                @line_numbers{@lines} = (1) x @lines;
            }

            my $filename = $file->name;

            local $opt_color = 0;

            iterate( $file, sub {
                chomp;

                if ( $line_numbers{$.} ) {
                    print_line_with_context( $filename, $_, $. );
                }
                elsif ( $opt_passthru ) {
                    print_line_with_options( $filename, $_, $., ':' );
                }
                elsif ( $is_tracking_context ) {
                    print_line_if_context( $filename, $_, $., '-' );
                }
                return 1;
            });
        }
        # ack -c
        elsif ( $opt_count ) {
            my $matches_for_this_file = count_matches_in_file( $file );

            if ( not $opt_show_filename ) {
                $total_count += $matches_for_this_file;
                next FILES;
            }

            if ( !$opt_l || $matches_for_this_file > 0) {
                if ( $opt_show_filename ) {
                    App::Ack::print( $file->name, ':', $matches_for_this_file, $ors );
                }
                else {
                    App::Ack::print( $matches_for_this_file, $ors );
                }
            }
        }
        # ack -l, ack -L
        elsif ( $opt_l || $opt_L ) {
            my $is_match = file_has_match( $file );

            if ( $opt_L ? !$is_match : $is_match ) {
                App::Ack::print( $file->name, $ors );
                ++$nmatches;

                last FILES if $only_first;
                last FILES if defined($opt_m) && $nmatches >= $opt_m;
            }
        }
        # Normal match-showing ack
        else {
            $nmatches += print_matches_in_file( $file, $opt );
            if ( $nmatches && $only_first ) {
                last FILES;
            }
        }
    }

    if ( $opt_count && !$opt_show_filename ) {
        App::Ack::print( $total_count, "\n" );
    }

    close $App::Ack::fh;

    App::Ack::exit_from_ack( $nmatches );
}

# End of MAIN

sub _compile_descend_filter {
    my ( $opt ) = @_;

    my $idirs = 0;
    my $dont_ignore_dirs = 0;

    for my $filter (@{$opt->{idirs} || []}) {
        if ($filter->is_inverted()) {
            $dont_ignore_dirs++;
        }
        else {
            $idirs++;
        }
    }

    # If we have one or more --noignore-dir directives, we can't ignore
    # entire subdirectory hierarchies, so we return an "accept all"
    # filter and scrutinize the files more in _compile_file_filter.
    return if $dont_ignore_dirs;
    return unless $idirs;

    $idirs = $opt->{idirs};

    return sub {
        my $file = App::Ack::File->new($File::Next::dir);
        return !grep { $_->filter($file) } @{$idirs};
    };
}

sub _compile_file_filter {
    my ( $opt, $start ) = @_;

    my $ifiles_filters = $opt->{ifiles};

    my $filters         = $opt->{'filters'} || [];
    my $direct_filters = App::Ack::Filter::Collection->new();
    my $inverse_filters = App::Ack::Filter::Collection->new();

    foreach my $filter (@{$filters}) {
        if ($filter->is_inverted()) {
            # We want to check if files match the uninverted filters
            $inverse_filters->add($filter->invert());
        }
        else {
            $direct_filters->add($filter);
        }
    }

    my %is_member_of_starting_set = map { (get_file_id($_) => 1) } @{$start};

    my @ignore_dir_filter = @{$opt->{idirs} || []};
    my @is_inverted       = map { $_->is_inverted() } @ignore_dir_filter;
    # This depends on InverseFilter->invert returning the original filter (for optimization).
    @ignore_dir_filter         = map { $_->is_inverted() ? $_->invert() : $_ } @ignore_dir_filter;
    my $dont_ignore_dir_filter = grep { $_ } @is_inverted;
    my $previous_dir = '';
    my $previous_dir_ignore_result;

    return sub {
        if ( $opt_g ) {
            if ( $File::Next::name =~ /$opt_regex/ && $opt_v ) {
                return 0;
            }
            if ( $File::Next::name !~ /$opt_regex/ && !$opt_v ) {
                return 0;
            }
        }
        # ack always selects files that are specified on the command
        # line, regardless of filetype.  If you want to ack a JPEG,
        # and say "ack foo whatever.jpg" it will do it for you.
        return 1 if $is_member_of_starting_set{ get_file_id($File::Next::name) };

        if ( $dont_ignore_dir_filter ) {
            if ( $previous_dir eq $File::Next::dir ) {
                if ( $previous_dir_ignore_result ) {
                    return 0;
                }
            }
            else {
                my @dirs = File::Spec->splitdir($File::Next::dir);

                my $is_ignoring = 0;

                for ( my $i = 0; $i < @dirs; $i++) {
                    my $dir_rsrc = App::Ack::File->new(File::Spec->catfile(@dirs[0 .. $i]));

                    my $j = 0;
                    for my $filter (@ignore_dir_filter) {
                        if ( $filter->filter($dir_rsrc) ) {
                            $is_ignoring = !$is_inverted[$j];
                        }
                        $j++;
                    }
                }

                $previous_dir               = $File::Next::dir;
                $previous_dir_ignore_result = $is_ignoring;

                if ( $is_ignoring ) {
                    return 0;
                }
            }
        }

        # Ignore named pipes found in directory searching.  Named
        # pipes created by subprocesses get specified on the command
        # line, so the rule of "always select whatever is on the
        # command line" wins.
        return 0 if -p $File::Next::name;

        # We can't handle unreadable filenames; report them.
        if ( not -r _ ) {
            use filetest 'access';

            if ( not -R $File::Next::name ) {
                if ( $App::Ack::report_bad_filenames ) {
                    App::Ack::warn( "${File::Next::name}: cannot open file for reading" );
                }
                return 0;
            }
        }

        my $file = App::Ack::File->new($File::Next::name);

        if ( $ifiles_filters && $ifiles_filters->filter($file) ) {
            return 0;
        }

        my $match_found = $direct_filters->filter($file);

        # Don't bother invoking inverse filters unless we consider the current file a match.
        if ( $match_found && $inverse_filters->filter( $file ) ) {
            $match_found = 0;
        }
        return $match_found;
    };
}


# Returns a (fairly) unique identifier for a file.
# Use this function to compare two files to see if they're
# equal (ie. the same file, but with a different path/links/etc).
sub get_file_id {
    my ( $filename ) = @_;

    if ( $App::Ack::is_windows ) {
        return File::Next::reslash( $filename );
    }
    else {
        # XXX Is this the best method? It always hits the FS.
        if ( my ( $dev, $inode ) = (stat($filename))[0, 1] ) {
            return join(':', $dev, $inode);
        }
        else {
            # XXX This could be better.
            return $filename;
        }
    }
}

# Returns a regex object based on a string and command-line options.
# Dies when the regex $str is undefined (i.e. not given on command line).

sub build_regex {
    my $str = shift;
    my $opt = shift;

    defined $str or App::Ack::die( 'No regular expression found.' );

    # Check for lowercaseness before we do any modifications.
    my $regex_is_lc = $str eq lc $str;

    $str = quotemeta( $str ) if $opt->{Q};

    # Whole words only.
    if ( $opt->{w} ) {
        my $ok = 1;

        if ( $str =~ /^\\[wd]/ ) {
            # Explicit \w is good.
        }
        else {
            # Can start with \w, (, [ or dot.
            if ( $str !~ /^[\w\(\[\.]/ ) {
                $ok = 0;
            }
        }

        # Can end with \w, }, ), ], +, *, or dot.
        if ( $str !~ /[\w\}\)\]\+\*\?\.]$/ ) {
            $ok = 0;
        }
        # ... unless it's escaped.
        elsif ( $str =~ /\\[\}\)\]\+\*\?\.]$/ ) {
            $ok = 0;
        }

        if ( !$ok ) {
            App::Ack::die( '-w will not do the right thing if your regex does not begin and end with a word character.' );
        }

        if ( $str =~ /^\w+$/ ) {
            # No need for fancy regex if it's a simple word.
            $str = sprintf( '\b(?:%s)\b', $str );
        }
        else {
            $str = sprintf( '(?:^|\b|\s)\K(?:%s)(?=\s|\b|$)', $str );
        }
    }

    if ( $opt->{i} || ($opt->{smart_case} && $regex_is_lc) ) {
        $str = "(?i)$str";
    }

    my $re = eval { qr/$str/m };
    if ( !$re ) {
        my $err = $@;
        chomp $err;
        App::Ack::die( "Invalid regex '$str':\n  $err" );
    }

    return $re;

}

my $match_colno;

{

# Number of context lines
my $n_before_ctx_lines;
my $n_after_ctx_lines;

# Array to keep track of lines that might be required for a "before" context
my @before_context_buf;
# Position to insert next line in @before_context_buf
my $before_context_pos;

# Number of "after" context lines still pending
my $after_context_pending;

# Number of latest line that got printed
my $printed_lineno;

my $is_iterating;

my $is_first_match;
state $has_printed_something = 0;

# Set up context tracking variables.
sub set_up_line_context {
    $n_before_ctx_lines = $opt_output ? 0 : ($opt_before_context || 0);
    $n_after_ctx_lines  = $opt_output ? 0 : ($opt_after_context || 0);

    @before_context_buf = (undef) x $n_before_ctx_lines;
    $before_context_pos = 0;

    $is_tracking_context = $n_before_ctx_lines || $n_after_ctx_lines;

    $is_first_match = 1;

    return;
}

# Adjust context tracking variables when entering a new file.
sub set_up_line_context_for_file {
    $printed_lineno = 0;
    $after_context_pending = 0;
    if ( $opt_heading && !$opt_lines ) {
        $is_first_match = 1;
    }

    return;
}


sub print_matches_in_file {
    my ( $file ) = @_;

    my $max_count = $opt_m || -1;   # Go negative for no limit so it can never reduce to 0.
    my $nmatches  = 0;
    my $filename  = $file->name;
    my $ors       = $opt_print0 ? "\0" : "\n";

    my $has_printed_for_this_file = 0;

    $is_iterating = 1;

    my $fh = $file->open;
    if ( !$fh ) {
        if ( $App::Ack::report_bad_filenames ) {
            App::Ack::warn( "$filename: $!" );
        }
        return 0;
    }

    my $display_filename = $filename;
    if ( $opt_show_filename && $opt_heading && $opt_color ) {
        $display_filename = Term::ANSIColor::colored($display_filename, $ENV{ACK_COLOR_FILENAME});
    }

    # Check for context before the main loop, so we don't pay for it if we don't need it.
    if ( $is_tracking_context ) {
        $after_context_pending = 0;
        while ( <$fh> ) {
            chomp;
            if ( does_match( $_ ) && $max_count ) {
                if ( !$has_printed_for_this_file ) {
                    if ( $opt_break && $has_printed_something ) {
                        App::Ack::print_blank_line();
                    }
                    if ( $opt_show_filename && $opt_heading ) {
                        App::Ack::print_filename( $display_filename, $ors );
                    }
                }
                print_line_with_context( $filename, $_, $. );
                $has_printed_for_this_file = 1;
                $nmatches++;
                $max_count--;
            }
            elsif ( $opt_passthru ) {
                # XXX Inline this call?
                if ( $opt_break && !$has_printed_for_this_file && $has_printed_something ) {
                    App::Ack::print_blank_line();
                }
                print_line_with_options( $filename, $_, $., ':' );
                $has_printed_for_this_file = 1;
            }
            else {
                print_line_if_context( $filename, $_, $., '-' );
            }

            last if ($max_count == 0) && ($after_context_pending == 0);
        }
    }
    else {  # Not tracking context
        if ( $opt_passthru ) {
            local $_ = undef;

            while ( <$fh> ) {
                chomp;
                $match_colno = undef;
                if ( $opt_v ? !/$opt_regex/o : /$opt_regex/o ) {
                    if ( !$opt_v ) {
                        $match_colno = $-[0] + 1;
                    }
                    if ( !$has_printed_for_this_file ) {
                        if ( $opt_break && $has_printed_something ) {
                            App::Ack::print_blank_line();
                        }
                        if ( $opt_show_filename && $opt_heading ) {
                            App::Ack::print_filename( $display_filename, $ors );
                        }
                    }
                    print_line_with_context( $filename, $_, $. );
                    $has_printed_for_this_file = 1;
                    $nmatches++;
                    $max_count--;
                }
                else {
                    if ( $opt_break && !$has_printed_for_this_file && $has_printed_something ) {
                        App::Ack::print_blank_line();
                    }
                    print_line_with_options( $filename, $_, $., ':' );
                    $has_printed_for_this_file = 1;
                }
                last if $max_count == 0;
            }
        }
        elsif ( $opt_v ) {
            local $_ = undef;

            $match_colno = undef;
            while ( <$fh> ) {
                chomp;
                if ( !/$opt_regex/o ) {
                    if ( !$has_printed_for_this_file ) {
                        if ( $opt_break && $has_printed_something ) {
                            App::Ack::print_blank_line();
                        }
                        if ( $opt_show_filename && $opt_heading ) {
                            App::Ack::print_filename( $display_filename, $ors );
                        }
                    }
                    print_line_with_context( $filename, $_, $. );
                    $has_printed_for_this_file = 1;
                    $nmatches++;
                    $max_count--;
                }
                last if $max_count == 0;
            }
        }
        else {
            local $_ = undef;

            my $last_match_lineno;
            while ( <$fh> ) {
                chomp;
                $match_colno = undef;
                if ( /$opt_regex/o ) {
                    $match_colno = $-[0] + 1;
                    if ( !$has_printed_for_this_file ) {
                        if ( $opt_break && $has_printed_something ) {
                            App::Ack::print_blank_line();
                        }
                        if ( $opt_show_filename && $opt_heading ) {
                            App::Ack::print_filename( $display_filename, $ors );
                        }
                    }
                    if ( $opt_proximate ) {
                        if ( $last_match_lineno ) {
                            if ( $. > $last_match_lineno + $opt_proximate ) {
                                App::Ack::print_blank_line();
                            }
                        }
                        elsif ( !$opt_break && $has_printed_something ) {
                            App::Ack::print_blank_line();
                        }
                    }
                    s/[\r\n]+$//g;
                    print_line_with_options( $filename, $_, $., ':' );
                    $has_printed_for_this_file = 1;
                    $nmatches++;
                    $max_count--;
                    $last_match_lineno = $.;
                }
                last if $max_count == 0;
            }
        }

    }

    $is_iterating = 0;

    return $nmatches;
}


sub print_line_with_options {
    my ( $filename, $line, $lineno, $separator ) = @_;

    $has_printed_something = 1;
    $printed_lineno = $lineno;

    my $ors = $opt_print0 ? "\0" : "\n";

    my @line_parts;

    # Figure out how many spaces are used per line for the ANSI coloring.
    state $chars_used_by_coloring;
    if ( !defined($chars_used_by_coloring) ) {
        $chars_used_by_coloring = 0;
        if ( $opt_color ) {
            my $filename_uses = length( Term::ANSIColor::colored( 'x', $ENV{ACK_COLOR_FILENAME} ) ) - 1;
            my $lineno_uses   = length( Term::ANSIColor::colored( 'x', $ENV{ACK_COLOR_LINENO} ) ) - 1;
            if ( $opt_heading ) {
                $chars_used_by_coloring = $lineno_uses;
            }
            else {
                $chars_used_by_coloring = $filename_uses + $lineno_uses;
            }
            if ( $opt_column ) {
                $chars_used_by_coloring += length( Term::ANSIColor::colored( 'x', $ENV{ACK_COLOR_LINENO} ) ) - 1;
            }
        }
    }

    if ( $opt_show_filename ) {
        my $colno;
        $colno = get_match_colno() if $opt_column;
        if ( $opt_color ) {
            $filename = Term::ANSIColor::colored( $filename, $ENV{ACK_COLOR_FILENAME} );
            $lineno   = Term::ANSIColor::colored( $lineno,   $ENV{ACK_COLOR_LINENO} );
            $colno    = Term::ANSIColor::colored( $colno,    $ENV{ACK_COLOR_COLNO} ) if $opt_column;
        }
        if ( $opt_heading ) {
            push @line_parts, $lineno;
            push @line_parts, $colno if $opt_column;
        }
        else {
            push @line_parts, $filename, $lineno;
            push @line_parts, $colno if $opt_column;
        }
    }

    if ( $opt_output ) {
        while ( $line =~ /$opt_regex/og ) {
            no strict;

            my $output = $opt_output;

            # Stash copies of the special variables because we can't rely
            # on them not changing in the process of doing the s///.
            my %keep = map { ($_ => ${$_} // '') } @special_vars_used_by_opt_output;
            $keep{_} = $line if exists $keep{_}; # Manually set it because $_ gets reset in a map.
            $keep{f} = $filename if exists $keep{f};
            $output =~ s/\$([$special_vars_used_by_opt_output])/$keep{$1}/ego;
            App::Ack::print( join( $separator, @line_parts, $output ), $ors );
        }
    }
    else {
        my $underline = '';

        # We have to do underlining before any highlighting because highlighting modifies string length.
        if ( $opt_u ) {
            while ( $line =~ /$opt_regex/og ) {
                my $match_start = $-[0];
                next unless defined($match_start);

                my $match_end = $+[0];
                my $match_length = $match_end - $match_start;
                last if $match_length <= 0;

                my $spaces_needed = $match_start - length $underline;

                $underline .= (' ' x $spaces_needed);
                $underline .= ('^' x $match_length);
            }
        }
        if ( $opt_color ) {
            my $highlighted = 0; # If highlighted, need to escape afterwards.

            while ( $line =~ /$opt_regex/og ) {
                my $match_start = $-[0];
                next unless defined($match_start);

                my $match_end = $+[0];
                my $match_length = $match_end - $match_start;
                last if $match_length <= 0;

                if ( $opt_color ) {
                    my $substring    = substr( $line, $match_start, $match_length );
                    my $substitution = Term::ANSIColor::colored( $substring, $ENV{ACK_COLOR_MATCH} );

                    # Fourth argument replaces the string specified by the first three.
                    substr( $line, $match_start, $match_length, $substitution );

                    # Move the offset of where /g left off forward the number of spaces of highlighting.
                    pos($line) = $match_end + (length( $substitution ) - length( $substring ));
                    $highlighted = 1;
                }
            }
            # Reset formatting and delete everything to the end of the line.
            $line .= "\e[0m\e[K" if $highlighted;
        }

        push @line_parts, $line;
        App::Ack::print( join( $separator, @line_parts ), $ors );

        if ( $underline ne '' ) {
            pop @line_parts; # Leave only the stuff on the left.
            if ( @line_parts ) {
                my $stuff_on_the_left = join( $separator, @line_parts );
                my $spaces_needed = length($stuff_on_the_left) - $chars_used_by_coloring + 1;

                App::Ack::print( ' ' x $spaces_needed );
            }
            App::Ack::print( $underline, $ors );
        }
    }

    return;
}

sub iterate {
    my ( $file, $cb ) = @_;

    $is_iterating = 1;

    my $fh = $file->open;
    if ( !$fh ) {
        if ( $App::Ack::report_bad_filenames ) {
            App::Ack::warn( $file->name . ': ' . $! );
        }
        return;
    }

    # Check for context before the main loop, so we don't pay for it if we don't need it.
    if ( $is_tracking_context ) {
        $after_context_pending = 0;

        while ( <$fh> ) {
            last unless $cb->();
        }
    }
    else {
        local $_ = undef;

        while ( <$fh> ) {
            last unless $cb->();
        }
    }

    $is_iterating = 0;

    return;
}

sub print_line_with_context {
    my ( $filename, $matching_line, $lineno ) = @_;

    my $ors = $opt_print0 ? "\0" : "\n";

    $matching_line =~ s/[\r\n]+$//g;

    # Check if we need to print context lines first.
    if ( $opt_after_context || $opt_before_context ) {
        my $before_unprinted = $lineno - $printed_lineno - 1;
        if ( !$is_first_match && ( !$printed_lineno || $before_unprinted > $n_before_ctx_lines ) ) {
            App::Ack::print('--', $ors);
        }

        # We want at most $n_before_ctx_lines of context.
        if ( $before_unprinted > $n_before_ctx_lines ) {
            $before_unprinted = $n_before_ctx_lines;
        }

        while ( $before_unprinted > 0 ) {
            my $line = $before_context_buf[($before_context_pos - $before_unprinted + $n_before_ctx_lines) % $n_before_ctx_lines];

            chomp $line;

            # Disable $opt->{column} since there are no matches in the context lines.
            local $opt_column = 0;

            print_line_with_options( $filename, $line, $lineno-$before_unprinted, '-' );
            $before_unprinted--;
        }
    }

    print_line_with_options( $filename, $matching_line, $lineno, ':' );

    # We want to get the next $n_after_ctx_lines printed.
    $after_context_pending = $n_after_ctx_lines;

    $is_first_match = 0;

    return;
}

# Print the line only if it's part of a context we need to display.
sub print_line_if_context {
    my ( $filename, $line, $lineno, $separator ) = @_;

    if ( $after_context_pending ) {
        # Disable $opt_column since there are no matches in the context lines.
        local $opt_column = 0;
        print_line_with_options( $filename, $line, $lineno, $separator );
        --$after_context_pending;
    }
    elsif ( $n_before_ctx_lines ) {
        # Save line for "before" context.
        $before_context_buf[$before_context_pos] = $_;
        $before_context_pos = ($before_context_pos+1) % $n_before_ctx_lines;
    }

    return;
}

}

# does_match() MUST have an $opt_regex set.


sub does_match {
    my ( $line ) = @_;

    $match_colno = undef;

    if ( $opt_v ) {
        return ( $line !~ /$opt_regex/o );
    }
    else {
        if ( $line =~ /$opt_regex/o ) {
            # @- = @LAST_MATCH_START
            # @+ = @LAST_MATCH_END
            $match_colno = $-[0] + 1;
            return 1;
        }
        else {
            return;
        }
    }
}

sub get_match_colno {
    return $match_colno;
}

sub file_has_match {
    my ( $file ) = @_;

    my $has_match = 0;
    my $fh = $file->open();
    if ( !$fh ) {
        if ( $App::Ack::report_bad_filenames ) {
            App::Ack::warn( $file->name . ': ' . $! );
        }
    }
    else {
        while ( <$fh> ) {
            chomp;
            if (/$opt_regex/o xor $opt_v) {
                $has_match = 1;
                last;
            }
        }
        close $fh;
    }

    return $has_match;
}

sub count_matches_in_file {
    my ( $file ) = @_;

    my $nmatches = 0;
    my $fh = $file->open;
    if ( !$fh ) {
        if ( $App::Ack::report_bad_filenames ) {
            App::Ack::warn( $file->name . ': ' . $! );
        }
    }
    else {
        while ( <$fh> ) {
            ++$nmatches if (/$opt_regex/o xor $opt_v);
        }
        close $fh;
    }

    return $nmatches;
}
package App::Ack;

use warnings;
use strict;


our $VERSION;
our $COPYRIGHT;
BEGIN {
    $VERSION = '2.999_01';
    $COPYRIGHT = 'Copyright 2005-2018 Andy Lester.';
}
our $STANDALONE = 0;
our $ORIGINAL_PROGRAM_NAME;

our $fh;

BEGIN {
    $fh = *STDOUT;
}


our %types;
our %type_wanted;
our %mappings;
our %ignore_dirs;

our $is_filter_mode;
our $output_to_pipe;

our $dir_sep_chars;
our $is_cygwin;
our $is_windows;

use File::Spec 1.00015 ();

BEGIN {
    # These have to be checked before any filehandle diddling.
    $output_to_pipe  = not -t *STDOUT;
    $is_filter_mode = -p STDIN;

    $is_cygwin       = ($^O eq 'cygwin' || $^O eq 'msys');
    $is_windows      = ($^O eq 'MSWin32');
    $dir_sep_chars   = $is_windows ? quotemeta( '\\/' ) : quotemeta( File::Spec->catfile( '', '' ) );
}



sub remove_dir_sep {
    my $path = shift;
    $path =~ s/[$dir_sep_chars]$//;

    return $path;
}



sub warn {
    return CORE::warn( _my_program(), ': ', @_, "\n" );
}


sub die {
    return CORE::die( _my_program(), ': ', @_, "\n" );
}

sub _my_program {
    require File::Basename;
    return File::Basename::basename( $0 );
}


sub thpppt {
    my $y = q{_   /|,\\'!.x',=(www)=,   U   };
    $y =~ tr/,x!w/\nOo_/;

    App::Ack::print( "$y ack $_[0]!\n" );
    exit 0;
}

sub ackbar {
    my $x;
    $x = <<'_BAR';
 6?!I'7!I"?%+!
 3~!I#7#I"7#I!?!+!="+"="+!:!
 2?#I!7!I!?#I!7!I"+"=%+"=#
 1?"+!?*+!=#~"=!+#?"="+!
 0?"+!?"I"?&+!="~!=!~"=!+%="+"
 /I!+!?)+!?!+!=$~!=!~!="+!="+"?!="?!
 .?%I"?%+%='?!=#~$="
 ,,!?%I"?(+$=$~!=#:"~$:!~!
 ,I!?!I!?"I"?!+#?"+!?!+#="~$:!~!:!~!:!,!:!,":#~!
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 *+!I!?!+$=!+!=!+!?$+#=!~":!~":#,$:",#:!,!:!
 *I!?"+!?!+!=$+!?#+#=#~":$,!:",!:!,&:"
 )I!?$=!~!=#+"?!+!=!+!=!~!="~!:!~":!,'.!,%:!~!
 (=!?"+!?!=!~$?"+!?!+!=#~"=",!="~$,$.",#.!:!=!
 (I"+"="~"=!+&=!~"=!~!,!~!+!=!?!+!?!=!I!?!+"=!.",!.!,":!
 %I$?!+!?!=%+!~!+#~!=!~#:#=!~!+!~!=#:!,%.!,!.!:"
 $I!?!=!?!I!+!?"+!=!~!=!~!?!I!?!=!+!=!~#:",!~"=!~!:"~!=!:",&:" '-/
 $?!+!I!?"+"=!+"~!,!:"+#~#:#,"=!~"=!,!~!,!.",!:".!:! */! !I!t!'!s! !a! !g!r!e!p!!! !/!
 $+"=!+!?!+"~!=!:!~!:"I!+!,!~!=!:!~!,!:!,$:!~".&:"~!,# (-/
 %~!=!~!=!:!.!+"~!:!,!.!,!~!=!:$.!,":!,!.!:!~!,!:!=!.#="~!,!:" ./!
 %=!~!?!+"?"+!=!~",!.!:!?!~!.!:!,!:!,#.!,!:","~!:!=!~!=!:",!~! ./!
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 &~!=!~!=!~!:"~#:",!.!,#~!:!.!+!,!.",$.",$.#,!+!I!?!
 &~!="~!:!~":!~",!~!=!~":!,!:!~!,!:!,&.$,#."+!?!I!?!I!
 &~!=!~!=!+!,!:!~!:!=!,!:!~&:$,!.!,".!,".!,#."~!+!?$I!
 &~!=!~!="~!=!:!~":!,!~%:#,!:",!.!,#.",#I!7"I!?!+!?"I"
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 %7#?!+!~!:!=!~!=!~":!,!:"~":#.!,)7#I"?"I!7&
 %7#I!=":!=!~!:"~$:"~!:#,!:!,!:!~!:#,!7#I!?#7)
 $7$+!,!~!=#~!:!~!:!~$:#,!.!~!:!=!,":!7#I"?#7+=!?!
 $7#I!~!,!~#=!~!:"~!:!,!:!,#:!=!~",":!7$I!?#I!7*+!=!+"
 "I!7$I!,":!,!.!=":$,!:!,$:$7$I!+!?"I!7+?"I!7!I!7!,!
 !,!7%I!:",!."~":!,&.!,!:!~!I!7$I!+!?"I!7,?!I!7',!
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7+:!,!~#,"=!7'I!?#I"7/+!7+
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_BAR

    return _pic_decode($x);
}

sub cathy {
    my $x = <<'CATHY';
 0+!--+!
 0|! "C!H!O!C!O!L!A!T!E!!! !|!
 0|! "C!H!O!C!O!L!A!T!E!!! !|!
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CATHY
    return _pic_decode($x);
}

sub _pic_decode {
    my($compressed) = @_;
    $compressed =~ s/(.)(.)/$1x(ord($2)-32)/eg;
    App::Ack::print( $compressed );
    exit 0;
}


sub show_help {
    my $help_arg = shift || 0;

    return show_help_types() if $help_arg =~ /^types?/;

    App::Ack::print( <<"END_OF_HELP" );
Usage: ack [OPTION]... PATTERN [FILES OR DIRECTORIES]

Search for PATTERN in each source file in the tree from the current
directory on down.  If any files or directories are specified, then
only those files and directories are checked.  ack may also search
STDIN, but only if no file or directory arguments are specified,
or if one of them is "-".

Default switches may be specified in ACK_OPTIONS environment variable or
an .ackrc file. If you want no dependency on the environment, turn it
off with --noenv.

Example: ack -i select

Searching:
  -i, --ignore-case             Ignore case distinctions in PATTERN
  -S, --[no]smart-case          Ignore case distinctions in PATTERN,
                                only if PATTERN contains no upper case.
                                Ignored if -i or -I are specified.
  -I                            Turns on case-sensitivity in PATTERN.
                                Negates -i and --smart-case.
  -v, --invert-match            Invert match: select non-matching lines
  -w, --word-regexp             Force PATTERN to match only whole words
  -Q, --literal                 Quote all metacharacters; PATTERN is literal
  --lines=NUM                   Only print line(s) NUM of each file.  No
                                pattern is matched.
  --match PATTERN               Specify PATTERN explicitly. Typically omitted.

Search output:
  -l, --files-with-matches      Only print filenames containing matches
  -L, --files-without-matches   Only print filenames with no matches
  --output=expr                 Output the evaluation of expr for each line
                                (turns off text highlighting)
  -o                            Show only the part of a line matching PATTERN
                                Same as --output='\$&'
  --passthru                    Print all lines, whether matching or not
  -m, --max-count=NUM           Stop searching in each file after NUM matches
  -1                            Stop searching after one match of any kind
  -H, --with-filename           Print the filename for each match (default:
                                on unless explicitly searching a single file)
  -h, --no-filename             Suppress the prefixing filename on output
  -c, --count                   Show number of lines matching per file
  --[no]column                  Show the column number of the first match

  -A NUM, --after-context=NUM   Print NUM lines of trailing context after
                                matching lines.
  -B NUM, --before-context=NUM  Print NUM lines of leading context before
                                matching lines.
  -C [NUM], --context[=NUM]     Print NUM lines (default 2) of output context.

  --print0                      Print null byte as separator between filenames,
                                only works with -f, -g, -l, -L or -c.

  -s                            Suppress error messages about nonexistent or
                                unreadable files.


File presentation:
  --pager=COMMAND               Pipes all ack output through COMMAND.  For
                                example, --pager="less -R".  Ignored if output
                                is redirected.
  --nopager                     Do not send output through a pager.  Cancels
                                any setting in ~/.ackrc, ACK_PAGER or
                                ACK_PAGER_COLOR.
  --[no]heading                 Print a filename heading above each file's
                                results.  (default: on when used interactively)
  --[no]break                   Print a break between results from different
                                files.  (default: on when used interactively)
  --group                       Same as --heading --break
  --nogroup                     Same as --noheading --nobreak
  --[no]proximate               Separate match output with blank lines unless
                                they are on adjacent lines.
  --[no]color                   Highlight the matching text (default: on unless
                                output is redirected, or on Windows)
  --[no]colour                  Same as --[no]color
  --color-filename=COLOR
  --color-match=COLOR
  --color-colno=COLOR
  --color-lineno=COLOR          Set the color for filenames, matches, line and
                                column numbers.
  --flush                       Flush output immediately, even when ack is used
                                non-interactively (when output goes to a pipe or
                                file).


File finding:
  -f                            Only print the files selected, without
                                searching.  The PATTERN must not be specified.
  -g                            Same as -f, but only select files matching
                                PATTERN.
  --sort-files                  Sort the found files lexically.
  --show-types                  Show which types each file has.
  --files-from=FILE             Read the list of files to search from FILE.
  -x                            Read the list of files to search from STDIN.

File inclusion/exclusion:
  --[no]ignore-dir=name         Add/remove directory from list of ignored dirs
  --[no]ignore-directory=name   Synonym for ignore-dir
  --ignore-file=FILTER:ARGS     Add filter for ignoring files.
  -r, -R, --recurse             Recurse into subdirectories (default: on)
  -n, --no-recurse              No descending into subdirectories
  --[no]follow                  Follow symlinks.  Default is off.

File type inclusion/exclusion:
  --type=X                      Include only X files, where X is a recognized
                                filetype, e.g. --php, --ruby
  --type=noX                    Exclude X files, e.g. --nophp, --no-ruby.
  -k, --known-types             Include only files of types that ack recognizes.
  --help-types                  Display all known types, and how they're defined.

File type specification:
  --type-set=TYPE:FILTER:ARGS   Files with the given ARGS applied to the given
                                FILTER are recognized as being of type TYPE.
                                This replaces an existing definition for TYPE.
  --type-add=TYPE:FILTER:ARGS   Files with the given ARGS applied to the given
                                FILTER are recognized as being type TYPE.
  --type-del=TYPE               Removes all filters associated with TYPE.

Miscellaneous:
  --version                     Display version & copyright
  --[no]env                     Ignore environment variables and global ackrc
                                files.  --env is legal but redundant.
  --ackrc=filename              Specify an ackrc file to use
  --ignore-ack-defaults         Ignore default definitions included with ack.
  --create-ackrc                Outputs a default ackrc for your customization
                                to standard output.
  --dump                        Dump information on which options are loaded
                                and where they're defined.
  --[no]filter                  Force ack to treat standard input as a pipe
                                (--filter) or tty (--nofilter)
  --help, -?                    This help
  --man                         Print the manual
  --faq                         Print the frequently asked questions
  --cookbook                    Print a list of tips and tricks for using ack
  --thpppt                      Bill the Cat
  --bar                         The warning admiral
  --cathy                       Chocolate! Chocolate! Chocolate!

Filter specifications:
    If FILTER is "ext", ARGS is a list of extensions checked against the
        file's extension.
    If FILTER is "is", ARGS must match the file's name exactly.
    If FILTER is "match", ARGS is matched as a case-insensitive regex
        against the filename.
    If FILTER is "firstlinematch", ARGS is matched as a regex the first
        line of the file's contents.

Exit status is 0 if match, 1 if no match.

ack's home page is at https://beyondgrep.com/

The full ack manual is available by running "ack --man".

This is version $VERSION of ack.  Run "ack --version" for full version info.
END_OF_HELP

    return;
 }



sub show_help_types {
    App::Ack::print( <<'END_OF_HELP' );
Usage: ack [OPTION]... PATTERN [FILES OR DIRECTORIES]

The following is the list of filetypes supported by ack.  You can
specify a file type with the --type=TYPE format, or the --TYPE
format.  For example, both --type=perl and --perl work.

Note that some extensions may appear in multiple types.  For example,
.pod files are both Perl and Parrot.

END_OF_HELP

    my @types = keys %App::Ack::mappings;
    my $maxlen = 0;
    for ( @types ) {
        $maxlen = length if $maxlen < length;
    }
    for my $type ( sort @types ) {
        next if $type =~ /^-/; # Stuff to not show
        my $ext_list = $mappings{$type};

        if ( ref $ext_list ) {
            $ext_list = join( '; ', map { $_->to_string } @{$ext_list} );
        }
        App::Ack::print( sprintf( "    --[no]%-*.*s %s\n", $maxlen, $maxlen, $type, $ext_list ) );
    }

    return;
}


sub show_docs {
    my $section = shift;

    require Pod::Usage;

    if ( $App::Ack::STANDALONE ) {
        # Right now we just show all POD for the standalone.
        Pod::Usage::pod2usage({
            -input     => $App::Ack::ORIGINAL_PROGRAM_NAME,
            -verbose   => 2,
            -exitval   => 0,
        });
    }
    else {
        my $module = "App::Ack::Docs::$section";
        eval "require $module" or App::Ack::die( "Can't load $module" );

        Pod::Usage::pod2usage({
            -input     => $INC{ "App/Ack/Docs/$section.pm" },
            -verbose   => 2,
            -exitval   => 0,
        });
    }

    return;
}



sub get_version_statement {
    require Config;

    my $copyright = $App::Ack::COPYRIGHT;
    my $this_perl = $Config::Config{perlpath};
    if ($^O ne 'VMS') {
        my $ext = $Config::Config{_exe};
        $this_perl .= $ext unless $this_perl =~ m/$ext$/i;
    }
    my $ver = sprintf( '%vd', $^V );

    my $build_type = $App::Ack::STANDALONE ? 'standalone version' : 'standard build';

    return <<"END_OF_VERSION";
ack ${VERSION} ($build_type)
Running under Perl $ver at $this_perl

$copyright

This program is free software.  You may modify or distribute it
under the terms of the Artistic License v2.0.
END_OF_VERSION
}


sub print                   { print {$fh} @_; return; }
sub print_blank_line        { App::Ack::print( "\n" ); return; }
sub print_filename          { App::Ack::print( $_[0], $_[1] ); return; }

sub set_up_pager {
    my $command = shift;

    return if App::Ack::output_to_pipe();

    my $pager;
    if ( not open( $pager, '|-', $command ) ) {
        App::Ack::die( qq{Unable to pipe to pager "$command": $!} );
    }
    $fh = $pager;

    return;
}


sub output_to_pipe {
    return $output_to_pipe;
}


sub exit_from_ack {
    my $nmatches = shift;

    my $rc = $nmatches ? 0 : 1;
    exit $rc;
}


sub show_types {
    my $file = shift;
    my $ors  = shift;

    my @types = filetypes( $file );
    my $types = join( ',', @types );
    my $arrow = @types ? ' => ' : ' =>';
    App::Ack::print( $file->name, $arrow, join( ',', @types ), $ors );

    return;
}


sub filetypes {
    my ( $file ) = @_;

    my @matches;

    foreach my $k (keys %App::Ack::mappings) {
        my $filters = $App::Ack::mappings{$k};

        foreach my $filter (@{$filters}) {
            # Clone the file.
            my $clone = $file->clone;
            if ( $filter->filter($clone) ) {
                push @matches, $k;
                last;
            }
        }
    }

    # http://search.cpan.org/dist/Perl-Critic/lib/Perl/Critic/Policy/Subroutines/ProhibitReturnSort.pm
    @matches = sort @matches;
    return @matches;
}


1; # End of App::Ack
package App::Ack::ConfigDefault;

use warnings;
use strict;




sub options {
    return split( /\n/, _options_block() );
}


sub options_clean {
    return grep { /./ && !/^#/ } options();
}


sub _options_block {
    my $lines = <<'HERE';
# This is the default ackrc for ack version ==VERSION==.

# There are four different ways to match
#
# is:  Match the filename exactly
#
# ext: Match the extension of the filename exactly
#
# match: Match the filename against a Perl regular expression
#
# firstlinematch: Match the first 250 characters of the first line
#   of text against a Perl regular expression.  This is only for
#   the --type-add option.


### Directories to ignore

# Bazaar
# http://bazaar.canonical.com/
--ignore-directory=is:.bzr

# Codeville
# http://freecode.com/projects/codeville
--ignore-directory=is:.cdv

# Interface Builder (Xcode)
# http://en.wikipedia.org/wiki/Interface_Builder
--ignore-directory=is:~.dep
--ignore-directory=is:~.dot
--ignore-directory=is:~.nib
--ignore-directory=is:~.plst

# Git
# http://git-scm.com/
--ignore-directory=is:.git
# When submodules are used, .git is a file.
--ignore-file=is:.git

# Mercurial
# http://mercurial.selenic.com/
--ignore-directory=is:.hg

# quilt
# http://directory.fsf.org/wiki/Quilt
--ignore-directory=is:.pc

# Subversion
# http://subversion.tigris.org/
--ignore-directory=is:.svn

# Monotone
# http://www.monotone.ca/
--ignore-directory=is:_MTN

# CVS
# http://savannah.nongnu.org/projects/cvs
--ignore-directory=is:CVS

# RCS
# http://www.gnu.org/software/rcs/
--ignore-directory=is:RCS

# SCCS
# http://en.wikipedia.org/wiki/Source_Code_Control_System
--ignore-directory=is:SCCS

# darcs
# http://darcs.net/
--ignore-directory=is:_darcs

# Vault/Fortress
--ignore-directory=is:_sgbak

# autoconf
# http://www.gnu.org/software/autoconf/
--ignore-directory=is:autom4te.cache

# Perl module building
--ignore-directory=is:blib
--ignore-directory=is:_build

# Perl Devel::Cover module's output directory
# https://metacpan.org/release/Devel-Cover
--ignore-directory=is:cover_db

# Node modules created by npm
--ignore-directory=is:node_modules

# CMake cache
# http://www.cmake.org/
--ignore-directory=is:CMakeFiles

# Eclipse workspace folder
# http://eclipse.org/
--ignore-directory=is:.metadata

# Cabal (Haskell) sandboxes
# http://www.haskell.org/cabal/users-guide/installing-packages.html
--ignore-directory=is:.cabal-sandbox

### Files to ignore

# Backup files
--ignore-file=ext:bak
--ignore-file=match:/~$/

# Emacs swap files
--ignore-file=match:/^#.+#$/

# vi/vim swap files http://vim.org/
--ignore-file=match:/[._].*\.swp$/

# core dumps
--ignore-file=match:/core\.\d+$/

# minified Javascript
--ignore-file=match:/[.-]min[.]js$/
--ignore-file=match:/[.]js[.]min$/

# minified CSS
--ignore-file=match:/[.]min[.]css$/
--ignore-file=match:/[.]css[.]min$/

# JS and CSS source maps
--ignore-file=match:/[.]js[.]map$/
--ignore-file=match:/[.]css[.]map$/

# PDFs, because they pass Perl's -T detection
--ignore-file=ext:pdf

# Common graphics, just as an optimization
--ignore-file=ext:gif,jpg,jpeg,png

# Common archives, as an optimization
--ignore-file=ext:gz,tar,tgz,zip


### Filetypes defined

# Makefiles
# http://www.gnu.org/s/make/
--type-add=make:ext:mk
--type-add=make:ext:mak
--type-add=make:is:makefile
--type-add=make:is:Makefile
--type-add=make:is:Makefile.Debug
--type-add=make:is:Makefile.Release
--type-add=make:is:GNUmakefile

# Rakefiles
# http://rake.rubyforge.org/
--type-add=rake:is:Rakefile

# CMake
# http://www.cmake.org/
--type-add=cmake:is:CMakeLists.txt
--type-add=cmake:ext:cmake

# Actionscript
--type-add=actionscript:ext:as,mxml

# Ada
# http://www.adaic.org/
--type-add=ada:ext:ada,adb,ads

# ASP
# http://msdn.microsoft.com/en-us/library/aa286483.aspx
--type-add=asp:ext:asp

# ASP.Net
# http://www.asp.net/
--type-add=aspx:ext:master,ascx,asmx,aspx,svc

# Assembly
--type-add=asm:ext:asm,s

# DOS/Windows batch
--type-add=batch:ext:bat,cmd

# ColdFusion
# http://en.wikipedia.org/wiki/ColdFusion
--type-add=cfmx:ext:cfc,cfm,cfml

# Clojure
# http://clojure.org/
--type-add=clojure:ext:clj,cljs,edn,cljc

# C
# .xs are Perl C files
--type-add=cc:ext:c,h,xs

# C header files
--type-add=hh:ext:h

# CoffeeScript
# http://coffeescript.org/
--type-add=coffeescript:ext:coffee

# C++
--type-add=cpp:ext:cpp,cc,cxx,m,hpp,hh,h,hxx

# C++ header files
--type-add=hpp:ext:hpp,hh,h,hxx

# C#
--type-add=csharp:ext:cs

# CSS
# http://www.w3.org/Style/CSS/
--type-add=css:ext:css

# Dart
# http://www.dartlang.org/
--type-add=dart:ext:dart

# Delphi
# http://en.wikipedia.org/wiki/Embarcadero_Delphi
--type-add=delphi:ext:pas,int,dfm,nfm,dof,dpk,dproj,groupproj,bdsgroup,bdsproj

# Elixir
# http://elixir-lang.org/
--type-add=elixir:ext:ex,exs

# Emacs Lisp
# http://www.gnu.org/software/emacs
--type-add=elisp:ext:el

# Erlang
# http://www.erlang.org/
--type-add=erlang:ext:erl,hrl

# Fortran
# http://en.wikipedia.org/wiki/Fortran
--type-add=fortran:ext:f,f77,f90,f95,f03,for,ftn,fpp

# Go
# http://golang.org/
--type-add=go:ext:go

# Groovy
# http://groovy.codehaus.org/
--type-add=groovy:ext:groovy,gtmpl,gpp,grunit,gradle

# GSP
# http://groovy.codehaus.org/GSP
--type-add=gsp:ext:gsp

# Haskell
# http://www.haskell.org/
--type-add=haskell:ext:hs,lhs

# HTML
--type-add=html:ext:htm,html,xhtml

# Jade
# http://jade-lang.com/
--type-add=jade:ext:jade

# Java
# http://www.oracle.com/technetwork/java/index.html
--type-add=java:ext:java,properties

# JavaScript
--type-add=js:ext:js

# JSP
# http://www.oracle.com/technetwork/java/javaee/jsp/index.html
--type-add=jsp:ext:jsp,jspx,jspf,jhtm,jhtml

# JSON
# http://www.json.org/
--type-add=json:ext:json

# Kotlin
# https://kotlinlang.org/
--type-add=kotlin:ext:kt,kts

# Less
# http://www.lesscss.org/
--type-add=less:ext:less

# Common Lisp
# http://common-lisp.net/
--type-add=lisp:ext:lisp,lsp

# Lua
# http://www.lua.org/
--type-add=lua:ext:lua
--type-add=lua:firstlinematch:/^#!.*\blua(jit)?/

# Markdown
# https://en.wikipedia.org/wiki/Markdown
--type-add=markdown:ext:md,markdown
# We understand that there are many ad hoc extensions for markdown
# that people use.  .md and .markdown are the two that ack recognizes.
# You are free to add your own in your ackrc file.

# Matlab
# http://en.wikipedia.org/wiki/MATLAB
--type-add=matlab:ext:m

# Objective-C
--type-add=objc:ext:m,h

# Objective-C++
--type-add=objcpp:ext:mm,h

# OCaml
# http://caml.inria.fr/
--type-add=ocaml:ext:ml,mli,mll,mly

# Parrot
# http://www.parrot.org/
--type-add=parrot:ext:pir,pasm,pmc,ops,pod,pg,tg

# Perl
# http://perl.org/
--type-add=perl:ext:pl,pm,pod,t,psgi
--type-add=perl:firstlinematch:/^#!.*\bperl/

# Perl tests
--type-add=perltest:ext:t

# Perl's Plain Old Documentation format, POD
--type-add=pod:ext:pod

# PHP
# http://www.php.net/
--type-add=php:ext:php,phpt,php3,php4,php5,phtml
--type-add=php:firstlinematch:/^#!.*\bphp/

# Plone
# http://plone.org/
--type-add=plone:ext:pt,cpt,metadata,cpy,py

# Python
# http://www.python.org/
--type-add=python:ext:py
--type-add=python:firstlinematch:/^#!.*\bpython/

# R
# http://www.r-project.org/
--type-add=rr:ext:R

# reStructured Text
# http://docutils.sourceforge.net/rst.html
--type-add=rst:ext:rst

# Ruby
# http://www.ruby-lang.org/
--type-add=ruby:ext:rb,rhtml,rjs,rxml,erb,rake,spec
--type-add=ruby:is:Rakefile
--type-add=ruby:firstlinematch:/^#!.*\bruby/

# Rust
# http://www.rust-lang.org/
--type-add=rust:ext:rs

# Sass
# http://sass-lang.com
--type-add=sass:ext:sass,scss

# Scala
# http://www.scala-lang.org/
--type-add=scala:ext:scala

# Scheme
# http://groups.csail.mit.edu/mac/projects/scheme/
--type-add=scheme:ext:scm,ss

# Shell
--type-add=shell:ext:sh,bash,csh,tcsh,ksh,zsh,fish
--type-add=shell:firstlinematch:/^#!.*\b(?:ba|t?c|k|z|fi)?sh\b/

# Smalltalk
# http://www.smalltalk.org/
--type-add=smalltalk:ext:st

# Smarty
# http://www.smarty.net/
--type-add=smarty:ext:tpl

# SQL
# http://www.iso.org/iso/catalogue_detail.htm?csnumber=45498
--type-add=sql:ext:sql,ctl

# Stylus
# http://learnboost.github.io/stylus/
--type-add=stylus:ext:styl

# Swift
# https://developer.apple.com/swift/
--type-add=swift:ext:swift
--type-add=swift:firstlinematch:/^#!.*\bswift/

# Tcl
# http://www.tcl.tk/
--type-add=tcl:ext:tcl,itcl,itk

# LaTeX
# http://www.latex-project.org/
--type-add=tex:ext:tex,cls,sty

# Template Toolkit (Perl)
# http://template-toolkit.org/
--type-add=tt:ext:tt,tt2,ttml

# Visual Basic
--type-add=vb:ext:bas,cls,frm,ctl,vb,resx

# Verilog
--type-add=verilog:ext:v,vh,sv

# VHDL
# http://www.eda.org/twiki/bin/view.cgi/P1076/WebHome
--type-add=vhdl:ext:vhd,vhdl

# Vim
# http://www.vim.org/
--type-add=vim:ext:vim

# XML
# http://www.w3.org/TR/REC-xml/
--type-add=xml:ext:xml,dtd,xsd,xsl,xslt,ent,wsdl
--type-add=xml:firstlinematch:/<[?]xml/

# YAML
# http://yaml.org/
--type-add=yaml:ext:yaml,yml
HERE
    $lines =~ s/==VERSION==/$App::Ack::VERSION/sm;

    return $lines;
}

1;
package App::Ack::ConfigFinder;


use strict;
use warnings;

use Cwd 3.00 ();
use File::Spec 3.00;

use if ($^O eq 'MSWin32'), 'Win32';


sub new {
    my ( $class ) = @_;

    return bless {}, $class;
}


sub _remove_redundancies {
    my @configs = @_;

    my %seen;
    my @uniq;
    foreach my $config (@configs) {
        my $path = $config->{path};
        my $key = -e $path ? Cwd::realpath( $path ) : $path;
        if ( not $App::Ack::is_windows ) {
            # On Unix, uniquify on inode.
            my ($dev, $inode) = (stat $key)[0, 1];
            $key = "$dev:$inode" if defined $dev;
        }
        push( @uniq, $config ) unless $seen{$key}++;
    }
    return @uniq;
}


sub _check_for_ackrc {
    return unless defined $_[0];

    my @files = grep { -f }
                map { File::Spec->catfile(@_, $_) }
                qw(.ackrc _ackrc);

    App::Ack::die( File::Spec->catdir(@_) . ' contains both .ackrc and _ackrc. Please remove one of those files.' )
        if @files > 1;

    return wantarray ? @files : $files[0];
} # end _check_for_ackrc



sub find_config_files {
    my @config_files;

    if ( $App::Ack::is_windows ) {
        push @config_files, map { +{ path => File::Spec->catfile($_, 'ackrc') } } (
            Win32::GetFolderPath(Win32::CSIDL_COMMON_APPDATA()),
            Win32::GetFolderPath(Win32::CSIDL_APPDATA()),
        );
    }
    else {
        push @config_files, { path => '/etc/ackrc' };
    }


    if ( $ENV{'ACKRC'} && -f $ENV{'ACKRC'} ) {
        push @config_files, { path => $ENV{'ACKRC'} };
    }
    else {
        push @config_files, map { +{ path => $_ } } _check_for_ackrc($ENV{'HOME'});
    }

    my $cwd = Cwd::getcwd();
    return () unless defined $cwd;

    # XXX This should go through some untainted cwd-fetching function, and not get untainted brute-force like this.
    $cwd =~ /(.+)/;
    $cwd = $1;
    my @dirs = File::Spec->splitdir( $cwd );
    while ( @dirs ) {
        my $ackrc = _check_for_ackrc(@dirs);
        if ( defined $ackrc ) {
            push @config_files, { project => 1, path => $ackrc };
            last;
        }
        pop @dirs;
    }

    # We only test for existence here, so if the file is deleted out from under us, this will fail later.
    return _remove_redundancies( @config_files );
}



sub read_rcfile {
    my $file = shift;

    return unless defined $file && -e $file;

    my @lines;

    open( my $fh, '<', $file ) or App::Ack::die( "Unable to read $file: $!" );
    while ( my $line = <$fh> ) {
        chomp $line;
        $line =~ s/^\s+//;
        $line =~ s/\s+$//;

        next if $line eq '';
        next if $line =~ /^\s*#/;

        push( @lines, $line );
    }
    close $fh or App::Ack::die( "Unable to close $file: $!" );

    return @lines;
}

1;
package App::Ack::ConfigLoader;

use strict;
use warnings;
use feature 'say';

use Carp 1.04 ();
use Getopt::Long 2.38 ();
use Text::ParseWords 3.1 ();


my @INVALID_COMBINATIONS;

BEGIN {
    my @context    = qw( -A -B -C --after-context --before-context --context );
    my @pretty     = qw( --heading --group --break );
    my @filename   = qw( -h -H --with-filename --no-filename );
    my @file_lists = qw( -f -g -l -L );

    @INVALID_COMBINATIONS = (
        [qw(-l)]                 => [@context, @pretty, @filename, qw(-L -o --passthru --output --max-count --column -f -g --show-types)],
        [qw(-L)]                 => [@context, @pretty, @filename, qw(-l -o --passthru --output --max-count --column -f -g --show-types -c --count)],
        [qw(--lines)]            => [@context, @pretty, @filename, qw(-l --files-with-matches --files-without-matches -L -o --passthru --match -m --max-count -1 -c --count --column --print0 -f -g --show-types)],
        [qw(-o)]                 => [@context, qw(--output -c --count --column --column -f --show-types)],
        [qw(--passthru)]         => [@context, qw(--output --column -m --max-count -1 -c --count -f -g)],
        [qw(--output)]           => [@context, qw(-c --count -f -g)],
        [qw(--match)]            => [qw(-f -g)],
        [qw(-m --max-count)]     => [qw(-1 -f -g -c --count)],
        [qw(-h --no-filename)]   => [qw(-H --with-filename -f -g --group --heading)],
        [qw(-H --with-filename)] => [qw(-h --no-filename -f -g)],
        [qw(-c --count)]         => [@context, @pretty, qw(--column -f -g)],
        [qw(--column)]           => [@file_lists],
        [@context]               => [@file_lists],
        [qw(-f)]                 => [qw(-g), @pretty],
        [qw(-g)]                 => [qw(-f), @pretty],
        [qw(--proximate)]        => [@context, @file_lists, qw( --passthru --lines -c )],
    );
}

sub _generate_ignore_dir {
    my ( $option_name, $opt ) = @_;

    my $is_inverted = $option_name =~ /^--no/;

    return sub {
        my ( undef, $dir ) = @_;

        $dir = App::Ack::remove_dir_sep( $dir );
        if ( $dir !~ /:/ ) {
            $dir = 'is:' . $dir;
        }

        my ( $filter_type, $args ) = split /:/, $dir, 2;

        if ( $filter_type eq 'firstlinematch' ) {
            Carp::croak( qq{Invalid filter specification "$filter_type" for option '$option_name'} );
        }

        my $filter = App::Ack::Filter->create_filter($filter_type, split(/,/, $args));
        my $collection;

        my $previous_inversion_matches = $opt->{idirs} && !($is_inverted xor $opt->{idirs}[-1]->is_inverted());

        if ( $previous_inversion_matches ) {
            $collection = $opt->{idirs}[-1];

            if ( $is_inverted ) {
                # This relies on invert of an inverted filter to return the original.
                $collection = $collection->invert();
            }
        }
        else {
            $collection = App::Ack::Filter::Collection->new();

            if ( $is_inverted ) {
                push @{ $opt->{idirs} }, $collection->invert();
            }
            else {
                push @{ $opt->{idirs} }, $collection;
            }
        }

        $collection->add($filter);

        if ( $filter_type eq 'is' ) {
            $collection->add(App::Ack::Filter::IsPath->new($args));
        }
    };
}

sub process_filter_spec {
    my ( $spec ) = @_;

    if ( $spec =~ /^(\w+):(\w+):(.*)/ ) {
        my ( $type_name, $ext_type, $arguments ) = ( $1, $2, $3 );

        return ( $type_name,
            App::Ack::Filter->create_filter($ext_type, split(/,/, $arguments)) );
    }
    elsif ( $spec =~ /^(\w+)=(.*)/ ) { # Check to see if we have ack1-style argument specification.
        my ( $type_name, $extensions ) = ( $1, $2 );

        my @extensions = split(/,/, $extensions);
        foreach my $extension ( @extensions ) {
            $extension =~ s/^[.]//;
        }

        return ( $type_name, App::Ack::Filter->create_filter('ext', @extensions) );
    }
    else {
        Carp::croak "invalid filter specification '$spec'";
    }
}


sub uninvert_filter {
    my ( $opt, @filters ) = @_;

    return unless defined $opt->{filters} && @filters;

    # Loop through all the registered filters.  If we hit one that
    # matches this extension and it's inverted, we need to delete it from
    # the options.
    for ( my $i = 0; $i < @{ $opt->{filters} }; $i++ ) {
        my $opt_filter = @{ $opt->{filters} }[$i];

        # XXX Do a real list comparison? This just checks string equivalence.
        if ( $opt_filter->is_inverted() && "$opt_filter->{filter}" eq "@filters" ) {
            splice @{ $opt->{filters} }, $i, 1;
            $i--;
        }
    }

    return;
}


sub process_filetypes {
    my ( $opt, $arg_sources ) = @_;

    Getopt::Long::Configure('default', 'no_auto_help', 'no_auto_version'); # start with default options, minus some annoying ones
    Getopt::Long::Configure(
        'no_ignore_case',
        'no_auto_abbrev',
        'pass_through',
    );
    my %additional_specs;

    my $add_spec = sub {
        my ( undef, $spec ) = @_;

        my ( $name, $filter ) = process_filter_spec($spec);

        push @{ $App::Ack::mappings{$name} }, $filter;

        $additional_specs{$name . '!'} = sub {
            my ( undef, $value ) = @_;

            my @filters = @{ $App::Ack::mappings{$name} };
            if ( not $value ) {
                @filters = map { $_->invert() } @filters;
            }
            else {
                uninvert_filter( $opt, @filters );
            }

            push @{ $opt->{'filters'} }, @filters;
        };
    };

    my $set_spec = sub {
        my ( undef, $spec ) = @_;

        my ( $name, $filter ) = process_filter_spec($spec);

        $App::Ack::mappings{$name} = [ $filter ];

        $additional_specs{$name . '!'} = sub {
            my ( undef, $value ) = @_;

            my @filters = @{ $App::Ack::mappings{$name} };
            if ( not $value ) {
                @filters = map { $_->invert() } @filters;
            }

            push @{ $opt->{'filters'} }, @filters;
        };
    };

    my $delete_spec = sub {
        my ( undef, $name ) = @_;

        delete $App::Ack::mappings{$name};
        delete $additional_specs{$name . '!'};
    };

    my %type_arg_specs = (
        'type-add=s' => $add_spec,
        'type-set=s' => $set_spec,
        'type-del=s' => $delete_spec,
    );

    foreach my $source (@{$arg_sources}) {
        my ( $source_name, $args ) = @{$source}{qw/name contents/};

        if ( ref($args) ) {
            # $args are modified in place, so no need to munge $arg_sources
            local @ARGV = @{$args};
            Getopt::Long::GetOptions(%type_arg_specs);
            @{$args} = @ARGV;
        }
        else {
            ( undef, $source->{contents} ) =
                Getopt::Long::GetOptionsFromString($args, %type_arg_specs);
        }
    }

    $additional_specs{'k|known-types'} = sub {
        my ( undef, $value ) = @_;

        my @filters = map { @{$_} } values(%App::Ack::mappings);

        push @{ $opt->{'filters'} }, @filters;
    };

    return \%additional_specs;
}


sub get_arg_spec {
    my ( $opt, $extra_specs ) = @_;


    return {
        1                   => sub { $opt->{1} = $opt->{m} = 1 },
        'A|after-context:-1'  => sub { shift; $opt->{after_context}  = _context_value(shift) },
        'B|before-context:-1' => sub { shift; $opt->{before_context} = _context_value(shift) },
        'C|context:-1'        => sub { shift; $opt->{before_context} = $opt->{after_context} = _context_value(shift) },
        'break!'            => \$opt->{break},
        c                   => \$opt->{count},
        'color|colour!'     => \$opt->{color},
        'color-match=s'     => \$ENV{ACK_COLOR_MATCH},
        'color-filename=s'  => \$ENV{ACK_COLOR_FILENAME},
        'color-colno=s'     => \$ENV{ACK_COLOR_COLNO},
        'color-lineno=s'    => \$ENV{ACK_COLOR_LINENO},
        'column!'           => \$opt->{column},
        count               => \$opt->{count},
        'create-ackrc'      => sub { say for ( '--ignore-ack-defaults', App::Ack::ConfigDefault::options() ); exit; },
        'env!'              => sub {
            my ( undef, $value ) = @_;

            if ( !$value ) {
                $opt->{noenv_seen} = 1;
            }
        },
        f                   => \$opt->{f},
        'files-from=s'      => \$opt->{files_from},
        'filter!'           => \$App::Ack::is_filter_mode,
        flush               => sub { $| = 1 },
        'follow!'           => \$opt->{follow},
        g                   => \$opt->{g},
        'group!'            => sub { shift; $opt->{heading} = $opt->{break} = shift },
        'heading!'          => \$opt->{heading},
        'h|no-filename'     => \$opt->{h},
        'H|with-filename'   => \$opt->{H},
        'i|ignore-case'     => sub { $opt->{i} = 1; $opt->{smart_case} = 0; },
        'I'                 => sub { $opt->{i} = 0; $opt->{smart_case} = 0; },
        'ignore-directory|ignore-dir=s' => _generate_ignore_dir('--ignore-dir', $opt),
        'ignore-file=s'     => sub {
            my ( undef, $file ) = @_;

            my ( $filter_type, $args ) = split /:/, $file, 2;

            my $filter = App::Ack::Filter->create_filter($filter_type, split(/,/, $args//''));

            if ( !$opt->{ifiles} ) {
                $opt->{ifiles} = App::Ack::Filter::Collection->new();
            }
            $opt->{ifiles}->add($filter);
        },
        'lines=s'           => sub { shift; my $val = shift; push @{$opt->{lines}}, $val },
        'l|files-with-matches'
                            => \$opt->{l},
        'L|files-without-matches'
                            => \$opt->{L},
        'm|max-count=i'     => \$opt->{m},
        'match=s'           => \$opt->{regex},
        'n|no-recurse'      => \$opt->{n},
        o                   => sub { $opt->{output} = '$&' },
        'output=s'          => \$opt->{output},
        'pager:s'           => sub {
            my ( undef, $value ) = @_;

            $opt->{pager} = $value || $ENV{PAGER};
        },
        'noignore-directory|noignore-dir=s' => _generate_ignore_dir('--noignore-dir', $opt),
        'nopager'           => sub { $opt->{pager} = undef },
        'passthru'          => \$opt->{passthru},
        'print0'            => \$opt->{print0},
        'proximate:1'       => \$opt->{proximate},
        'Q|literal'         => \$opt->{Q},
        'r|R|recurse'       => sub { $opt->{n} = 0 },
        's'                 => \$opt->{s},
        'show-types'        => \$opt->{show_types},
        'S|smart-case!'     => sub { my (undef,$value) = @_; $opt->{smart_case} = $value; $opt->{i} = 0 if $value; },
        'sort-files'        => \$opt->{sort_files},
        'type=s'            => sub {
            my ( $getopt, $value ) = @_;

            my $cb_value = 1;
            if ( $value =~ s/^no// ) {
                $cb_value = 0;
            }

            my $callback = $extra_specs->{ $value . '!' };

            if ( $callback ) {
                $callback->( $getopt, $cb_value );
            }
            else {
                Carp::croak( "Unknown type '$value'" );
            }
        },
        'u|underline!'      => \$opt->{u},
        'v|invert-match'    => \$opt->{v},
        'w|word-regexp'     => \$opt->{w},
        'x'                 => sub { $opt->{files_from} = '-' },

        'help|?:s'          => sub { shift; App::Ack::show_help(@_); exit; },
        'help-types'        => sub { App::Ack::show_help_types(); exit; },
        $extra_specs ? %{$extra_specs} : (),
    }; # arg_specs
}

sub _context_value {
    my $val = shift;

    # Contexts default to 2.
    return (!defined($val) || ($val < 0)) ? 2 : $val;
}


sub process_other {
    my ( $opt, $extra_specs, $arg_sources ) = @_;

    # Start with default options, minus some annoying ones.
    Getopt::Long::Configure('default', 'no_auto_help', 'no_auto_version');
    Getopt::Long::Configure(
        'bundling',
        'no_ignore_case',
    );

    my $argv_source;
    my $is_help_types_active;

    foreach my $source (@{$arg_sources}) {
        my ( $source_name, $args ) = @{$source}{qw/name contents/};

        if ( $source_name eq 'ARGV' ) {
            $argv_source = $args;
            last;
        }
    }

    if ( $argv_source ) { # This *should* always be true, but you never know...
        my @copy = @{$argv_source};
        local @ARGV = @copy;

        Getopt::Long::Configure('pass_through');

        Getopt::Long::GetOptions(
            'help-types' => \$is_help_types_active,
        );

        Getopt::Long::Configure('no_pass_through');
    }

    my $arg_specs = get_arg_spec($opt, $extra_specs);

    foreach my $source (@{$arg_sources}) {
        my ( $source_name, $args ) = @{$source}{qw/name contents/};

        my $args_for_source = { %{$arg_specs} };

        if ( $source->{is_ackrc} ) {
            my $illegal = sub {
                my $name = shift;
                App::Ack::die( "Option --$name is forbidden in .ackrc files." );
            };

            $args_for_source = {
                %{$args_for_source},
                'output=s' => $illegal,
                'match=s'  => $illegal,
            };
        }
        if ( $source->{project} ) {
            my $illegal = sub {
                my $name = shift;
                App::Ack::die( "Option --$name is forbidden in project .ackrc files." );
            };

            $args_for_source = {
                %{$args_for_source},
                'pager:s' => $illegal,
            };
        }

        my $ret;
        if ( ref($args) ) {
            local @ARGV = @{$args};
            $ret = Getopt::Long::GetOptions( %{$args_for_source} );
            @{$args} = @ARGV;
        }
        else {
            ( $ret, $source->{contents} ) =
                Getopt::Long::GetOptionsFromString( $args, %{$args_for_source} );
        }
        if ( !$ret ) {
            if ( !$is_help_types_active ) {
                my $where = $source_name eq 'ARGV' ? 'on command line' : "in $source_name";
                App::Ack::die( "Invalid option $where" );
            }
        }
        if ( $opt->{noenv_seen} ) {
            App::Ack::die( "--noenv found in $source_name" );
        }
    }

    # XXX We need to check on a -- in the middle of a non-ARGV source

    return;
}


sub should_dump_options {
    my ( $sources ) = @_;

    foreach my $source (@{$sources}) {
        my ( $name, $options ) = @{$source}{qw/name contents/};

        if ( $name eq 'ARGV' ) {
            my $dump;
            local @ARGV = @{$options};
            Getopt::Long::Configure('default', 'pass_through', 'no_auto_help', 'no_auto_version');
            Getopt::Long::GetOptions(
                'dump' => \$dump,
            );
            @{$options} = @ARGV;
            return $dump;
        }
    }
    return;
}


sub explode_sources {
    my ( $sources ) = @_;

    my @new_sources;

    Getopt::Long::Configure('default', 'pass_through', 'no_auto_help', 'no_auto_version');

    my %opt;
    my $arg_spec = get_arg_spec(\%opt);

    my $add_type = sub {
        my ( undef, $arg ) = @_;

        if ( $arg =~ /(\w+)=/) {
            $arg_spec->{$1} = sub {};
        }
        else {
            ( $arg ) = split /:/, $arg;
            $arg_spec->{$arg} = sub {};
        }
    };

    my $del_type = sub {
        my ( undef, $arg ) = @_;

        delete $arg_spec->{$arg};
    };

    foreach my $source (@{$sources}) {
        my ( $name, $options ) = @{$source}{qw/name contents/};
        if ( ref($options) ne 'ARRAY' ) {
            $source->{contents} = $options =
                [ Text::ParseWords::shellwords($options) ];
        }

        for my $j ( 0 .. @{$options}-1 ) {
            next unless $options->[$j] =~ /^-/;
            my @chunk = ( $options->[$j] );
            push @chunk, $options->[$j] while ++$j < @{$options} && $options->[$j] !~ /^-/;
            $j--;

            my @copy = @chunk;
            local @ARGV = @chunk;
            Getopt::Long::GetOptions(
                'type-add=s' => $add_type,
                'type-set=s' => $add_type,
                'type-del=s' => $del_type,
            );
            Getopt::Long::GetOptions( %{$arg_spec} );

            push @new_sources, {
                name     => $name,
                contents => \@copy,
            };
        }
    }

    return \@new_sources;
}


sub compare_opts {
    my ( $a, $b ) = @_;

    my $first_a = $a->[0];
    my $first_b = $b->[0];

    $first_a =~ s/^--?//;
    $first_b =~ s/^--?//;

    return $first_a cmp $first_b;
}


sub dump_options {
    my ( $sources ) = @_;

    $sources = explode_sources($sources);

    my %opts_by_source;
    my @source_names;

    foreach my $source (@{$sources}) {
        my ( $name, $contents ) = @{$source}{qw/name contents/};
        if ( not $opts_by_source{$name} ) {
            $opts_by_source{$name} = [];
            push @source_names, $name;
        }
        push @{$opts_by_source{$name}}, $contents;
    }

    foreach my $name (@source_names) {
        my $contents = $opts_by_source{$name};

        say $name;
        say '=' x length($name);
        say '  ', join(' ', @{$_}) for sort { compare_opts($a, $b) } @{$contents};
    }

    return;
}


sub remove_default_options_if_needed {
    my ( $sources ) = @_;

    my $default_index;

    foreach my $index ( 0 .. $#{$sources} ) {
        if ( $sources->[$index]{'name'} eq 'Defaults' ) {
            $default_index = $index;
            last;
        }
    }

    return $sources unless defined $default_index;

    my $should_remove = 0;

    # Start with default options, minus some annoying ones.
    Getopt::Long::Configure('default', 'no_auto_help', 'no_auto_version');
    Getopt::Long::Configure(
        'no_ignore_case',
        'no_auto_abbrev',
        'pass_through',
    );

    foreach my $index ( $default_index + 1 .. $#{$sources} ) {
        my ( $name, $args ) = @{$sources->[$index]}{qw/name contents/};

        if (ref($args)) {
            local @ARGV = @{$args};
            Getopt::Long::GetOptions(
                'ignore-ack-defaults' => \$should_remove,
            );
            @{$args} = @ARGV;
        }
        else {
            ( undef, $sources->[$index]{contents} ) = Getopt::Long::GetOptionsFromString($args,
                'ignore-ack-defaults' => \$should_remove,
            );
        }
    }

    Getopt::Long::Configure('default');
    Getopt::Long::Configure('default', 'no_auto_help', 'no_auto_version');

    return $sources unless $should_remove;

    my @copy = @{$sources};
    splice @copy, $default_index, 1;
    return \@copy;
}


sub check_for_mutually_exclusive_options {
    my ( $arg_sources ) = @_;

    my %mutually_exclusive_with;
    my @copy = @{$arg_sources};

    for ( my $i = 0; $i < @INVALID_COMBINATIONS; $i += 2 ) {
        my ( $lhs, $rhs ) = @INVALID_COMBINATIONS[ $i, $i + 1 ];

        foreach my $l_opt ( @{$lhs} ) {
            foreach my $r_opt ( @{$rhs} ) {
                push @{ $mutually_exclusive_with{ $l_opt } }, $r_opt;
                push @{ $mutually_exclusive_with{ $r_opt } }, $l_opt;
            }
        }
    }

    while ( @copy ) {
        my %set_opts;

        my $source = shift @copy;
        my ( $source_name, $args ) = @{$source}{qw/name contents/};
        $args = ref($args) ? [ @{$args} ] : [ Text::ParseWords::shellwords($args) ];

        foreach my $opt ( @{$args} ) {
            next unless $opt =~ /^[-+]/;
            last if $opt eq '--';

            if ( $opt =~ /^(.*)=/ ) {
                $opt = $1;
            }
            elsif ( $opt =~ /^(-[^-]).+/ ) {
                $opt = $1;
            }

            $set_opts{ $opt } = 1;

            my $mutex_opts = $mutually_exclusive_with{ $opt };

            next unless $mutex_opts;

            foreach my $mutex_opt ( @{$mutex_opts} ) {
                if ( $set_opts{ $mutex_opt } ) {
                    App::Ack::die( "Options '$mutex_opt' and '$opt' are mutually exclusive" );
                }
            }
        }
    }

    return;
}


sub process_args {
    my $arg_sources = \@_;

    my %opt = (
        pager => $ENV{ACK_PAGER_COLOR} || $ENV{ACK_PAGER},
    );

    check_for_mutually_exclusive_options($arg_sources);

    $arg_sources = remove_default_options_if_needed($arg_sources);

    if ( should_dump_options($arg_sources) ) {
        dump_options($arg_sources);
        exit(0);
    }

    my $type_specs = process_filetypes(\%opt, $arg_sources);
    process_other(\%opt, $type_specs, $arg_sources);
    while ( @{$arg_sources} ) {
        my $source = shift @{$arg_sources};
        my ( $source_name, $args ) = @{$source}{qw/name contents/};

        # All of our sources should be transformed into an array ref
        if ( ref($args) ) {
            if ( $source_name eq 'ARGV' ) {
                @ARGV = @{$args};
            }
            elsif (@{$args}) {
                Carp::croak "source '$source_name' has extra arguments!";
            }
        }
        else {
            Carp::croak 'The impossible has occurred!';
        }
    }
    my $filters = ($opt{filters} ||= []);

    # Throw the default filter in if no others are selected.
    if ( not grep { !$_->is_inverted() } @{$filters} ) {
        push @{$filters}, App::Ack::Filter::Default->new();
    }
    return \%opt;
}


sub retrieve_arg_sources {
    my @arg_sources;

    my $noenv;
    my $ackrc;

    Getopt::Long::Configure('default', 'no_auto_help', 'no_auto_version');
    Getopt::Long::Configure('pass_through');
    Getopt::Long::Configure('no_auto_abbrev');

    Getopt::Long::GetOptions(
        'noenv'   => \$noenv,
        'ackrc=s' => \$ackrc,
    );

    Getopt::Long::Configure('default', 'no_auto_help', 'no_auto_version');

    my @files;

    if ( !$noenv ) {
        my $finder = App::Ack::ConfigFinder->new;
        @files  = $finder->find_config_files;
    }
    if ( $ackrc ) {
        # We explicitly use open so we get a nice error message.
        # XXX This is a potential race condition!.
        if ( open my $fh, '<', $ackrc ) {
            close $fh;
        }
        else {
            App::Ack::die( "Unable to load ackrc '$ackrc': $!" );
        }
        push( @files, { path => $ackrc } );
    }

    push @arg_sources, {
        name     => 'Defaults',
        contents => [ App::Ack::ConfigDefault::options_clean() ],
    };

    foreach my $file ( @files) {
        my @lines = App::Ack::ConfigFinder::read_rcfile($file->{path});

        if ( @lines ) {
            push @arg_sources, {
                name     => $file->{path},
                contents => \@lines,
                project  => $file->{project},
                is_ackrc => 1,
            };
        }
    }

    if ( $ENV{ACK_OPTIONS} && !$noenv ) {
        push @arg_sources, {
            name     => 'ACK_OPTIONS',
            contents => $ENV{ACK_OPTIONS},
        };
    }

    push @arg_sources, {
        name     => 'ARGV',
        contents => [ @ARGV ],
    };

    return @arg_sources;
}

1; # End of App::Ack::ConfigLoader
package App::Ack::File;


use warnings;
use strict;


sub new {
    my $class    = shift;
    my $filename = shift;

    my $self = bless {
        filename => $filename,
        fh       => undef,
        opened   => 0,
    }, $class;

    if ( $self->{filename} eq '-' ) {
        $self->{fh}     = *STDIN;
        $self->{opened} = 1;
    }

    return $self;
}



sub name {
    return $_[0]->{filename};
}



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

    # XXX Definedness? Pre-populate the slot with an undef?
    unless ( exists $self->{basename} ) {
        $self->{basename} = (File::Spec->splitpath($self->name))[2];
    }

    return $self->{basename};
}



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

    if ( !$self->{opened} ) {
        if ( open $self->{fh}, '<', $self->{filename} ) {
            $self->{opened} = 1;
        }
        else {
            $self->{fh} = undef;
        }
    }

    return $self->{fh};
}



sub needs_line_scan {
    my $self  = shift;
    my $opt   = shift;

    return 1 if $opt->{v};

    my $size = -s $self->{fh};
    if ( $size == 0 ) {
        return 0;
    }
    elsif ( $size > 100_000 ) {
        return 1;
    }

    my $buffer;
    my $rc = sysread( $self->{fh}, $buffer, $size );
    if ( !defined($rc) && $App::Ack::report_bad_filenames ) {
        App::Ack::warn( "$self->{filename}: $!" );
        return 1;
    }
    return 0 unless $rc && ( $rc == $size );

    return $buffer =~ /$opt->{regex}/m;
}



sub reset {
    my $self = shift;

    if ( defined($self->{fh}) ) {
        if ( !seek( $self->{fh}, 0, 0 ) && $App::Ack::report_bad_filenames ) {
            App::Ack::warn( "$self->{filename}: $!" );
        }
    }

    return;
}



sub close {
    my $self = shift;

    # Return if we haven't opened the file yet.
    if ( !defined($self->{fh}) ) {
        return;
    }

    if ( !close($self->{fh}) && $App::Ack::report_bad_filenames ) {
        App::Ack::warn( $self->name() . ": $!" );
    }

    $self->{opened} = 0;

    return;
}



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

    return __PACKAGE__->new($self->name);
}



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

    if ( !exists $self->{firstliney} ) {
        my $fh = $self->open();
        if ( !$fh ) {
            if ( $App::Ack::report_bad_filenames ) {
                App::Ack::warn( $self->name . ': ' . $! );
            }
            $self->{firstliney} = '';
        }
        else {
            my $buffer;
            my $rc = sysread( $fh, $buffer, 250 );
            if ( $rc ) {
                $buffer =~ s/[\r\n].*//s;
            }
            else {
                if ( !defined($rc) ) {
                    App::Ack::warn( $self->name . ': ' . $! );
                }
                $buffer = '';
            }
            $self->{firstliney} = $buffer;
            $self->reset;
        }
    }

    return $self->{firstliney};
}

1;
package App::Ack::Files;


use Errno qw(EACCES);

use warnings;
use strict;


sub from_argv {
    my $class = shift;
    my $opt   = shift;
    my $start = shift;

    my $self = bless {}, $class;

    my $file_filter    = undef;
    my $descend_filter = $opt->{descend_filter};

    if ( $opt->{n} ) {
        $descend_filter = sub {
            return 0;
        };
    }

    $self->{iter} =
        File::Next::files( {
            file_filter     => $opt->{file_filter},
            descend_filter  => $descend_filter,
            error_handler   => _generate_error_handler($opt),
            warning_handler => sub {},
            sort_files      => $opt->{sort_files},
            follow_symlinks => $opt->{follow},
        }, @{$start} );

    return $self;
}


sub from_file {
    my $class = shift;
    my $opt   = shift;
    my $file  = shift;

    my $iter =
        File::Next::from_file( {
            error_handler   => _generate_error_handler($opt),
            warning_handler => _generate_error_handler($opt),
            sort_files      => $opt->{sort_files},
        }, $file ) or return undef;

    return bless {
        iter => $iter,
    }, $class;
}




sub from_stdin {
    my $class = shift;

    my $self  = bless {}, $class;

    my $has_been_called = 0;

    $self->{iter} = sub {
        if ( !$has_been_called ) {
            $has_been_called = 1;
            return '-';
        }
        return;
    };

    return $self;
}


sub next {
    my $self = shift;

    my $file = $self->{iter}->() or return;

    return App::Ack::File->new( $file );
}


sub _generate_error_handler {
    my $opt = shift;

    if ( $App::Ack::report_bad_filenames ) {
        return sub {
            my $msg = shift;
            App::Ack::warn( $msg );
        };
    }
    else {
        return sub {
            my $msg = shift;
            if ( $! == EACCES ) {
                return;
            }
            App::Ack::warn( $msg );
        };
    }
}

1;
package App::Ack::Filter;

use strict;
use warnings;

use Carp 1.04 ();

my %filter_types;


sub create_filter {
    my ( undef, $type, @args ) = @_;

    if ( my $package = $filter_types{$type} ) {
        return $package->new(@args);
    }
    my $allowed_types = join( ', ', sort keys %filter_types );
    App::Ack::die( "Unknown filter type '$type'.  Type must be one of: $allowed_types." );
}


sub register_filter {
    my ( undef, $type, $package ) = @_;

    $filter_types{$type} = $package;

    return;
}


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

    return App::Ack::Filter::Inverse->new( $self );
}


sub is_inverted {
    return 0;
}


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

    return '(unimplemented to_string)';
}


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

    return ref($self);
}

1;
package App::Ack::Filter::Collection;


use strict;
use warnings;
BEGIN {
    our @ISA = 'App::Ack::Filter';
}

sub new {
    my ( $class ) = @_;

    return bless {
        groups => {},
        ungrouped => [],
    }, $class;
}

sub filter {
    my ( $self, $file ) = @_;

    for my $group (values %{$self->{groups}}) {
        return 1 if $group->filter($file);
    }

    for my $filter (@{$self->{ungrouped}}) {
        return 1 if $filter->filter($file);
    }

    return 0;
}

sub add {
    my ( $self, $filter ) = @_;

    if (exists $filter->{'groupname'}) {
        my $group = ($self->{groups}->{$filter->{groupname}} ||= $filter->create_group());
        $group->add($filter);
    }
    else {
        push @{$self->{'ungrouped'}}, $filter;
    }

    return;
}

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

    return ref($self) . " - $self";
}

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

    return join(', ', map { "($_)" } @{$self->{ungrouped}});
}

1;
package App::Ack::Filter::Default;


use strict;
use warnings;
BEGIN {
    our @ISA = 'App::Ack::Filter';
}

sub new {
    my ( $class ) = @_;

    return bless {}, $class;
}

sub filter {
    my ( $self, $file ) = @_;

    return -T $file->name;
}

1;
package App::Ack::Filter::Extension;


use strict;
use warnings;
BEGIN {
    our @ISA = 'App::Ack::Filter';
}


sub new {
    my ( $class, @extensions ) = @_;

    my $exts = join('|', map { "\Q$_\E"} @extensions);
    my $re   = qr/[.](?:$exts)$/i;

    return bless {
        extensions => \@extensions,
        regex      => $re,
        groupname  => 'ExtensionGroup',
    }, $class;
}

sub create_group {
    return App::Ack::Filter::ExtensionGroup->new();
}

sub filter {
    my ( $self, $file ) = @_;

    return $file->name =~ /$self->{regex}/;
}

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

    return ref($self) . ' - ' . $self->{regex};
}

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

    return join( ' ', map { ".$_" } @{$self->{extensions}} );
}

BEGIN {
    App::Ack::Filter->register_filter(ext => __PACKAGE__);
}

1;
package App::Ack::Filter::ExtensionGroup;


use strict;
use warnings;
BEGIN {
    our @ISA = 'App::Ack::Filter';
}

sub new {
    my ( $class ) = @_;

    return bless {
        data => {},
    }, $class;
}

sub add {
    my ( $self, $filter ) = @_;

    foreach my $ext (@{$filter->{extensions}}) {
        $self->{data}->{lc $ext} = 1;
    }

    return;
}

sub filter {
    my ( $self, $file ) = @_;

    if ($file->name =~ /[.]([^.]*)$/) {
        return exists $self->{'data'}->{lc $1};
    }

    return 0;
}

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

    return ref($self) . " - $self";
}

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

    return join(' ', map { ".$_" } sort keys %{$self->{data}});
}

1;
package App::Ack::Filter::FirstLineMatch;



use strict;
use warnings;
BEGIN {
    our @ISA = 'App::Ack::Filter';
}

sub new {
    my ( $class, $re ) = @_;

    $re =~ s{^/|/$}{}g; # XXX validate?
    $re = qr{$re}i;

    return bless {
        regex => $re,
    }, $class;
}

# This test reads the first 250 characters of a file, then just uses the
# first line found in that. This prevents reading something  like an entire
# .min.js file (which might be only one "line" long) into memory.

sub filter {
    my ( $self, $file ) = @_;

    return $file->firstliney =~ /$self->{regex}/;
}

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


    return ref($self) . ' - ' . $self->{regex};
}

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

    (my $re = $self->{regex}) =~ s{\([^:]*:(.*)\)$}{$1};

    return "First line matches /$re/";
}

BEGIN {
    App::Ack::Filter->register_filter(firstlinematch => __PACKAGE__);
}

1;
package App::Ack::Filter::Inverse;



use strict;
use warnings;
BEGIN {
    our @ISA = 'App::Ack::Filter';
}

sub new {
    my ( $class, $filter ) = @_;

    return bless {
        filter => $filter,
    }, $class;
}

sub filter {
    my ( $self, $file ) = @_;

    return !$self->{filter}->filter( $file );
}

sub invert {
    my $self = shift;

    return $self->{'filter'};
}

sub is_inverted {
    return 1;
}

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

    my $filter = $self->{'filter'};

    return "!$filter";
}

1;
package App::Ack::Filter::Is;


use strict;
use warnings;
BEGIN {
    our @ISA = 'App::Ack::Filter';
}

use File::Spec 3.00 ();

sub new {
    my ( $class, $filename ) = @_;

    return bless {
        filename => $filename,
        groupname => 'IsGroup',
    }, $class;
}

sub create_group {
    return App::Ack::Filter::IsGroup->new();
}

sub filter {
    my ( $self, $file ) = @_;

    return (File::Spec->splitpath($file->name))[2] eq $self->{filename};
}

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

    return ref($self) . ' - ' . $self->{filename};
}

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

    return $self->{filename};
}

BEGIN {
    App::Ack::Filter->register_filter(is => __PACKAGE__);
}

1;
package App::Ack::Filter::IsGroup;


use strict;
use warnings;
BEGIN {
    our @ISA = 'App::Ack::Filter';
}

use File::Spec 3.00 ();

sub new {
    my ( $class ) = @_;

    return bless {
        data => {},
    }, $class;
}

sub add {
    my ( $self, $filter ) = @_;

    $self->{data}->{ $filter->{filename} } = 1;

    return;
}

sub filter {
    my ( $self, $file ) = @_;

    return exists $self->{data}->{ $file->basename };
}

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

    return ref($self) . " - $self";
}

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

    return join(' ', keys %{$self->{data}});
}

1;
package App::Ack::Filter::IsPath;


use strict;
use warnings;
BEGIN {
    our @ISA = 'App::Ack::Filter';
}


sub new {
    my ( $class, $filename ) = @_;

    return bless {
        filename => $filename,
        groupname => 'IsPathGroup',
    }, $class;
}

sub create_group {
    return App::Ack::Filter::IsPathGroup->new();
}

sub filter {
    my ( $self, $file ) = @_;

    return $file->name eq $self->{filename};
}

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

    return ref($self) . ' - ' . $self->{filename};
}

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

    return $self->{filename};
}

1;
package App::Ack::Filter::IsPathGroup;


use strict;
use warnings;
BEGIN {
    our @ISA = 'App::Ack::Filter';
}

sub new {
    my ( $class ) = @_;

    return bless {
        data => {},
    }, $class;
}

sub add {
    my ( $self, $filter ) = @_;

    $self->{data}->{ $filter->{filename} } = 1;

    return;
}

sub filter {
    my ( $self, $file ) = @_;

    return exists $self->{data}->{$file->name};
}

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

    return ref($self) . " - $self";
}

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

    return join(' ', keys %{$self->{data}});
}

1;
package App::Ack::Filter::Match;

use strict;
use warnings;
BEGIN {
    our @ISA = 'App::Ack::Filter';
}

use File::Spec 3.00;


sub new {
    my ( $class, $re ) = @_;

    $re =~ s{^/|/$}{}g; # XXX validate?
    $re = qr/$re/i;

    return bless {
        regex => $re,
        groupname => 'MatchGroup',
    }, $class;
}

sub create_group {
    return App::Ack::Filter::MatchGroup->new;
}

sub filter {
    my ( $self, $file ) = @_;

    return $file->basename =~ /$self->{regex}/;
}

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

    return ref($self) . ' - ' . $self->{regex};
}

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

    return "Filename matches $self->{regex}";
}

BEGIN {
    App::Ack::Filter->register_filter(match => __PACKAGE__);
}

1;
package App::Ack::Filter::MatchGroup;


use strict;
use warnings;
BEGIN {
    our @ISA = 'App::Ack::Filter';
}

sub new {
    my ( $class ) = @_;

    return bless {
        matches => [],
        big_re  => undef,
    }, $class;
}

sub add {
    my ( $self, $filter ) = @_;

    push @{ $self->{matches} }, $filter->{regex};

    my $re = join('|', map { "(?:$_)" } @{ $self->{matches} });
    $self->{big_re} = qr/$re/;

    return;
}

sub filter {
    my ( $self, $file ) = @_;

    return $file->basename =~ /$self->{big_re}/;
}

# This class has no inspect() or to_string() method.
# It will just use the default one unless someone writes something useful.

1;
package File::Next;

use strict;
use warnings;


our $VERSION = '1.16';



use File::Spec ();

our $name; # name of the current file
our $dir;  # dir of the current file

our %files_defaults;
our %skip_dirs;

BEGIN {
    %files_defaults = (
        file_filter     => undef,
        descend_filter  => undef,
        error_handler   => sub { CORE::die $_[0] },
        warning_handler => sub { CORE::warn @_ },
        sort_files      => undef,
        follow_symlinks => 1,
        nul_separated   => 0,
    );
    %skip_dirs = map {($_,1)} (File::Spec->curdir, File::Spec->updir);
}


sub files {
    die _bad_invocation() if @_ && defined($_[0]) && ($_[0] eq __PACKAGE__);

    my ($parms,@queue) = _setup( \%files_defaults, @_ );

    return sub {
        my $filter = $parms->{file_filter};
        while (@queue) {
            my ($dirname,$file,$fullpath) = splice( @queue, 0, 3 );
            if ( -f $fullpath || -p _ || $fullpath =~ m{^/dev/fd} ) {
                if ( $filter ) {
                    local $_ = $file;
                    local $File::Next::dir = $dirname;
                    local $File::Next::name = $fullpath;
                    next if not $filter->();
                }
                return wantarray ? ($dirname,$file,$fullpath) : $fullpath;
            }
            if ( -d _ ) {
                unshift( @queue, _candidate_files( $parms, $fullpath ) );
            }
        } # while

        return;
    }; # iterator
}






sub from_file {
    die _bad_invocation() if @_ && defined($_[0]) && ($_[0] eq __PACKAGE__);

    my ($parms,@queue) = _setup( \%files_defaults, @_ );
    my $err  = $parms->{error_handler};
    my $warn = $parms->{warning_handler};

    my $filename = $queue[1];

    if ( !defined($filename) ) {
        $err->( 'Must pass a filename to from_file()' );
        return undef;
    }

    my $fh;
    if ( $filename eq '-' ) {
        $fh = \*STDIN;
    }
    else {
        if ( !open( $fh, '<', $filename ) ) {
            $err->( "Unable to open $filename: $!", $! + 0 );
            return undef;
        }
    }

    return sub {
        my $filter = $parms->{file_filter};
        local $/ = $parms->{nul_separated} ? "\x00" : $/;
        while ( my $fullpath = <$fh> ) {
            chomp $fullpath;
            next unless $fullpath =~ /./;
            if ( not ( -f $fullpath || -p _ ) ) {
                $warn->( "$fullpath: No such file" );
                next;
            }

            my ($volume,$dirname,$file) = File::Spec->splitpath( $fullpath );
            if ( $filter ) {
                local $_ = $file;
                local $File::Next::dir  = $dirname;
                local $File::Next::name = $fullpath;
                next if not $filter->();
            }
            return wantarray ? ($dirname,$file,$fullpath) : $fullpath;
        } # while
        close $fh;

        return;
    }; # iterator
}

sub _bad_invocation {
    my $good = (caller(1))[3];
    my $bad  = $good;
    $bad =~ s/(.+)::/$1->/;
    return "$good must not be invoked as $bad";
}

sub sort_standard($$)   { return $_[0]->[1] cmp $_[1]->[1] }
sub sort_reverse($$)    { return $_[1]->[1] cmp $_[0]->[1] }

sub reslash {
    my $path = shift;

    my @parts = split( /\//, $path );

    return $path if @parts < 2;

    return File::Spec->catfile( @parts );
}



sub _setup {
    my $defaults = shift;
    my $passed_parms = ref $_[0] eq 'HASH' ? {%{+shift}} : {}; # copy parm hash

    my %passed_parms = %{$passed_parms};

    my $parms = {};
    for my $key ( keys %{$defaults} ) {
        $parms->{$key} =
            exists $passed_parms{$key}
                ? delete $passed_parms{$key}
                : $defaults->{$key};
    }

    # Any leftover keys are bogus
    for my $badkey ( keys %passed_parms ) {
        my $sub = (caller(1))[3];
        $parms->{error_handler}->( "Invalid option passed to $sub(): $badkey" );
    }

    # If it's not a code ref, assume standard sort
    if ( $parms->{sort_files} && ( ref($parms->{sort_files}) ne 'CODE' ) ) {
        $parms->{sort_files} = \&sort_standard;
    }
    my @queue;

    for ( @_ ) {
        my $start = reslash( $_ );
        if (-d $start) {
            push @queue, ($start,undef,$start);
        }
        else {
            push @queue, (undef,$start,$start);
        }
    }

    return ($parms,@queue);
}


sub _candidate_files {
    my $parms   = shift;
    my $dirname = shift;

    my $dh;
    if ( !opendir $dh, $dirname ) {
        $parms->{error_handler}->( "$dirname: $!", $! + 0 );
        return;
    }

    my @newfiles;
    my $descend_filter = $parms->{descend_filter};
    my $follow_symlinks = $parms->{follow_symlinks};
    my $sort_sub = $parms->{sort_files};

    for my $file ( grep { !exists $skip_dirs{$_} } readdir $dh ) {
        my $has_stat;

        my $fullpath = File::Spec->catdir( $dirname, $file );
        if ( !$follow_symlinks ) {
            next if -l $fullpath;
            $has_stat = 1;
        }

        # Only do directory checking if we have a descend_filter
        if ( $descend_filter ) {
            if ( $has_stat ? (-d _) : (-d $fullpath) ) {
                local $File::Next::dir = $fullpath;
                local $_ = $file;
                next if not $descend_filter->();
            }
        }
        if ( $sort_sub ) {
            push( @newfiles, [ $dirname, $file, $fullpath ] );
        }
        else {
            push( @newfiles, $dirname, $file, $fullpath );
        }
    }
    closedir $dh;

    if ( $sort_sub ) {
        return map { @{$_} } sort $sort_sub @newfiles;
    }

    return @newfiles;
}


1; # End of File::Next
package App::Ack::Docs::Manual;

=pod

=encoding UTF-8

=head1 NAME

ack - grep-like text finder

=head1 SYNOPSIS

    ack [options] PATTERN [FILE...]
    ack -f [options] [DIRECTORY...]

=head1 DESCRIPTION

ack is designed as an alternative to F<grep> for programmers.

ack searches the named input FILEs or DIRECTORYs for lines containing a
match to the given PATTERN.  By default, ack prints the matching lines.
If no FILE or DIRECTORY is given, the current directory will be searched.

PATTERN is a Perl regular expression.  Perl regular expressions
are commonly found in other programming languages, but for the particulars
of their behavior, please consult
L<http://perldoc.perl.org/perlreref.html|perlreref>.  If you don't know
how to use regular expression but are interested in learning, you may
consult L<http://perldoc.perl.org/perlretut.html|perlretut>.  If you do not
need or want ack to use regular expressions, please see the
C<-Q>/C<--literal> option.

Ack can also list files that would be searched, without actually
searching them, to let you take advantage of ack's file-type filtering
capabilities.

=head1 FILE SELECTION

If files are not specified for searching, either on the command
line or piped in with the C<-x> option, I<ack> delves into
subdirectories selecting files for searching.

I<ack> is intelligent about the files it searches.  It knows about
certain file types, based on both the extension on the file and,
in some cases, the contents of the file.  These selections can be
made with the B<--type> option.

With no file selection, I<ack> searches through regular files that
are not explicitly excluded by B<--ignore-dir> and B<--ignore-file>
options, either present in F<ackrc> files or on the command line.

The default options for I<ack> ignore certain files and directories.  These
include:

=over 4

=item * Backup files: Files matching F<#*#> or ending with F<~>.

=item * Coredumps: Files matching F<core.\d+>

=item * Version control directories like F<.svn> and F<.git>.

=back

Run I<ack> with the C<--dump> option to see what settings are set.

However, I<ack> always searches the files given on the command line,
no matter what type.  If you tell I<ack> to search in a coredump,
it will search in a coredump.

=head1 DIRECTORY SELECTION

I<ack> descends through the directory tree of the starting directories
specified.  If no directories are specified, the current working directory is
used.  However, it will ignore the shadow directories used by
many version control systems, and the build directories used by the
Perl MakeMaker system.  You may add or remove a directory from this
list with the B<--[no]ignore-dir> option. The option may be repeated
to add/remove multiple directories from the ignore list.

For a complete list of directories that do not get searched, run
C<ack --dump>.

=head1 OPTIONS

=over 4

=item B<--ackrc>

Specifies an ackrc file to load after all others; see L</"ACKRC LOCATION SEMANTICS">.

=item B<-A I<NUM>>, B<--after-context=I<NUM>>

Print I<NUM> lines of trailing context after matching lines.

=item B<-B I<NUM>>, B<--before-context=I<NUM>>

Print I<NUM> lines of leading context before matching lines.

=item B<--[no]break>

Print a break between results from different files. On by default
when used interactively.

=item B<-C [I<NUM>]>, B<--context[=I<NUM>]>

Print I<NUM> lines (default 2) of context around matching lines.
You can specify zero lines of context to override another context
specified in an ackrc.

=item B<-c>, B<--count>

Suppress normal output; instead print a count of matching lines for
each input file.  If B<-l> is in effect, it will only show the
number of lines for each file that has lines matching.  Without
B<-l>, some line counts may be zeroes.

If combined with B<-h> (B<--no-filename>) ack outputs only one total
count.

=item B<--[no]color>, B<--[no]colour>

B<--color> highlights the matching text.  B<--nocolor> suppresses
the color.  This is on by default unless the output is redirected.

On Windows, this option is off by default unless the
L<Win32::Console::ANSI> module is installed or the C<ACK_PAGER_COLOR>
environment variable is used.

=item B<--color-filename=I<color>>

Sets the color to be used for filenames.

=item B<--color-match=I<color>>

Sets the color to be used for matches.

=item B<--color-colno=I<color>>

Sets the color to be used for column numbers.

=item B<--color-lineno=I<color>>

Sets the color to be used for line numbers.

=item B<--[no]column>

Show the column number of the first match.  This is helpful for
editors that can place your cursor at a given position.

=item B<--cookbook>

Print the ack cookbook, a list of common tricks and recipes for using ack.

=item B<--create-ackrc>

Dumps the default ack options to standard output.  This is useful for
when you want to customize the defaults.

=item B<--dump>

Writes the list of options loaded and where they came from to standard
output.  Handy for debugging.

=item B<--[no]env>

B<--noenv> disables all environment processing. No F<.ackrc> is
read and all environment variables are ignored. By default, F<ack>
considers F<.ackrc> and settings in the environment.

=item B<--faq>

Print the list of frequently asked questions.

=item B<--flush>

B<--flush> flushes output immediately.  This is off by default
unless ack is running interactively (when output goes to a pipe or
file).

=item B<-f>

Only print the files that would be searched, without actually doing
any searching.  PATTERN must not be specified, or it will be taken
as a path to search.

=item B<--files-from=I<FILE>>

The list of files to be searched is specified in I<FILE>.  The list of
files are separated by newlines.  If I<FILE> is C<->, the list is loaded
from standard input.

Note that the list of files is B<not> filtered in any way.  If you
add C<--type=html> in addition to C<--files-from>, the C<--type> will
be ignored.


=item B<--[no]filter>

Forces ack to act as if it were receiving input via a pipe.

=item B<--[no]follow>

Follow or don't follow symlinks, other than whatever starting files
or directories were specified on the command line.

This is off by default.

=item B<-g I<PATTERN>>

Print searchable files where the relative path + filename matches
I<PATTERN>.

Note that

    ack -g foo

is exactly the same as

    ack -f | ack foo

This means that just as ack will not search, for example, F<.jpg>
files, C<-g> will not list F<.jpg> files either.  ack is not intended
to be a general-purpose file finder.

Note also that if you have C<-i> in your .ackrc that the filenames
to be matched will be case-insensitive as well.

This option can be combined with B<--color> to make it easier to
spot the match.

=item B<--[no]group>

B<--group> groups matches by file name.  This is the default
when used interactively.

B<--nogroup> prints one result per line, like grep.  This is the
default when output is redirected.

=item B<-H>, B<--with-filename>

Print the filename for each match. This is the default unless searching
a single explicitly specified file.

=item B<-h>, B<--no-filename>

Suppress the prefixing of filenames on output when multiple files are
searched.

=item B<--[no]heading>

Print a filename heading above each file's results.  This is the default
when used interactively.

=item B<--help>, B<-?>

Print a short help statement.

=item B<--help-types>, B<--help=types>

Print all known types.

=item B<-i>, B<--ignore-case>

Ignore case distinctions in PATTERN.  Overrides B<--smart-case> and B<-I>.

=item B<-I>

Turns on case distinctions in PATTERN.  Overrides B<--smart-case> and B<-i>.

=item B<--ignore-ack-defaults>

Tells ack to completely ignore the default definitions provided with ack.
This is useful in combination with B<--create-ackrc> if you I<really> want
to customize ack.

=item B<--[no]ignore-dir=I<DIRNAME>>, B<--[no]ignore-directory=I<DIRNAME>>

Ignore directory (as CVS, .svn, etc are ignored). May be used
multiple times to ignore multiple directories. For example, mason
users may wish to include B<--ignore-dir=data>. The B<--noignore-dir>
option allows users to search directories which would normally be
ignored (perhaps to research the contents of F<.svn/props> directories).

The I<DIRNAME> must always be a simple directory name. Nested
directories like F<foo/bar> are NOT supported. You would need to
specify B<--ignore-dir=foo> and then no files from any foo directory
are taken into account by ack unless given explicitly on the command
line.

=item B<--ignore-file=I<FILTER:ARGS>>

Ignore files matching I<FILTER:ARGS>.  The filters are specified
identically to file type filters as seen in L</"Defining your own types">.

=item B<-k>, B<--known-types>

Limit selected files to those with types that ack knows about.

=item B<--lines=I<NUM>>

Only print line I<NUM> of each file. Multiple lines can be given
with multiple B<--lines> options or as a comma separated list
(B<--lines=3,5,7>). Using a range such as B<--lines=4-7> also works. The
lines are always output in the order found in the file, no matter the
order given on the command line.

=item B<-l>, B<--files-with-matches>

Only print the filenames of matching files, instead of the matching text.

=item B<-L>, B<--files-without-matches>

Only print the filenames of files that do I<NOT> match.

=item B<--match I<PATTERN>>

Specify the I<PATTERN> explicitly. This is helpful if you don't want to put the
regex as your first argument, e.g. when executing multiple searches over the
same set of files.

    # search for foo and bar in given files
    ack file1 t/file* --match foo
    ack file1 t/file* --match bar

=item B<-m=I<NUM>>, B<--max-count=I<NUM>>

Print only I<NUM> matches out of each file.  If you want to stop ack
after printing the first match of any kind, use the B<-1> options.

=item B<--man>

Print this manual page.

=item B<-n>, B<--no-recurse>

No descending into subdirectories.

=item B<-o>

Show only the part of each line matching PATTERN (turns off text
highlighting).  This is exactly the same as C<--output=$&>.

=item B<--output=I<expr>>

Output the evaluation of I<expr> for each line (turns off text
highlighting). If PATTERN matches more than once then a line is
output for each non-overlapping match.

I<expr> may contain the strings "\n", "\r" and "\t", which will be
expanded to their corresponding characters line feed, carriage return
and tab, respectively.

I<expr> may also contain the following Perl special variables:

=over 4

=item C<$1> through C<$9>

The subpattern from the corresponding set of capturing parentheses.
If your pattern is C<(.+) and (.+)>, and the string is "this and
that', then C<$1> is "this" and C<$2> is "that".

=item C<$_>

The contents of the line in the file.

=item C<$.>

The number of the line in the file.

=item C<$&>, C<$`> and C<$'>

C<$&> is the the string matched by the pattern, C<$`> is what
precedes the match, and C<$'> is what follows it.  If the pattern
is C<gra(ph|nd)> and the string is "lexicographic", then C<$&> is
"graph", C<$`> is "lexico" and C<$'> is "ic".

Use of these variables in your output will slow down the pattern
matching.

=item C<$+>

The match made by the last parentheses that matched in the pattern.
For example, if your pattern is C<Version: (.+)|Revision: (.+)>,
then C<$+> will contain whichever set of parentheses matched.

=item C<$f>

C<$f> is available, in C<--output> only, to insert the filename.
This is a stand-in for the discovered C<$filename> usage in old C<< ack2 --output >>,
which is disallowed with C<ack3> improved security.

The intended usage is to provide the grep or compile-error syntax needed for editor/IDE go-to-line integration,
e.g. C<--output=$f:$.:$_> or C<--output=$f\t$.\t$&>

=back

For examples of using C<--output>, see the Cookbook section of the manual.

=item B<--pager=I<program>>, B<--nopager>

B<--pager> directs ack's output through I<program>.  This can also be specified
via the C<ACK_PAGER> and C<ACK_PAGER_COLOR> environment variables.

Using --pager does not suppress grouping and coloring like piping
output on the command-line does.

B<--nopager> cancels any setting in F<~/.ackrc>, C<ACK_PAGER> or C<ACK_PAGER_COLOR>.
No output will be sent through a pager.

=item B<--passthru>

Prints all lines, whether or not they match the expression.  Highlighting
will still work, though, so it can be used to highlight matches while
still seeing the entire file, as in:

    # Watch a log file, and highlight a certain IP address.
    $ tail -f ~/access.log | ack --passthru 123.45.67.89

=item B<--print0>

Only works in conjunction with B<-f>, B<-g>, B<-l> or B<-c>, options
that only list filenames.  The filenames are output separated with a
null byte instead of the usual newline. This is helpful when dealing
with filenames that contain whitespace, e.g.

    # Remove all files of type HTML.
    ack -f --html --print0 | xargs -0 rm -f

=item B<--proximate[=N]>

Groups together match lines that are within N lines of each other.
This is useful for visually picking out matches that appear close
to other matches.

For example, if you got these results without the C<--proximate> option,

    15: First match
    18: Second match
    19: Third match
    37: Fourth match

they would look like this with C<--proximate=1>

    15: First match

    18: Second match
    19: Third match

    37: Fourth match

and this with C<--proximate=3>.

    15: First match
    18: Second match
    19: Third match

    37: Fourth match

If N is omitted, N is set to 1.

=item B<-Q>, B<--literal>

Quote all metacharacters in PATTERN, it is treated as a literal.

=item B<-r>, B<-R>, B<--recurse>

Recurse into sub-directories. This is the default and just here for
compatibility with grep. You can also use it for turning B<--no-recurse> off.

=item B<-s>

Suppress error messages about nonexistent or unreadable files.  This is taken
from fgrep.

=item B<-S>, B<--[no]smart-case>, B<--no-smart-case>

Ignore case in the search strings if PATTERN contains no uppercase
characters. This is similar to C<smartcase> in the vim text editor.
The options overrides B<-i> and B<-I>.

B<-S> is a synonym for B<--smart-case>.

B<-i> always overrides this option.

=item B<--sort-files>

Sorts the found files lexicographically.  Use this if you want your file
listings to be deterministic between runs of I<ack>.

=item B<--show-types>

Outputs the filetypes that ack associates with each file.

Works with B<-f> and B<-g> options.

=item B<--type=[no]TYPE>

Specify the types of files to include or exclude from a search.
TYPE is a filetype, like I<perl> or I<xml>.  B<--type=perl> can
also be specified as B<--perl>, and B<--type=noperl> can be done
as B<--noperl>.

If a file is of both type "foo" and "bar", specifying --foo and
--nobar will exclude the file, because an exclusion takes precedence
over an inclusion.

Type specifications can be repeated and are ORed together.

See I<ack --help=types> for a list of valid types.

=item B<--type-add I<TYPE>:I<FILTER>:I<ARGS>>

Files with the given ARGS applied to the given FILTER
are recognized as being of (the existing) type TYPE.
See also L</"Defining your own types">.

=item B<--type-set I<TYPE>:I<FILTER>:I<ARGS>>

Files with the given ARGS applied to the given FILTER are recognized as
being of type TYPE. This replaces an existing definition for type TYPE.  See
also L</"Defining your own types">.

=item B<--type-del I<TYPE>>

The filters associated with TYPE are removed from Ack, and are no longer considered
for searches.

=item B<-u>, B<--[no]underline>

Turns on underlining of matches, where "underlining" is not a true
underlining, but printing a line of carets under the match.

    $ ack -u foo
    peanuts.txt
    17: Come kick the football you fool
                      ^^^          ^^^
    623: Price per square foot
                          ^^^

This is useful if you're dumping the results of an ack run into a text
file or printer and don't get any coloring.

The setting of underline does not affect highlighting of matches.

=item B<-v>, B<--invert-match>

Invert match: select non-matching lines.

=item B<--version>

Display version and copyright information.

=item B<-w>, B<--word-regexp>

Force PATTERN to match only whole words.

=item B<-x>

An abbreviation for B<--files-from=->. The list of files to search are read
from standard input, with one line per file.

Note that the list of files is B<not> filtered in any way.  If you add
C<--type=html> in addition to C<-x>, the C<--type> will be ignored.

=item B<-1>

Stops after reporting first match of any kind.  This is different
from B<--max-count=1> or B<-m1>, where only one match per file is
shown.  Also, B<-1> works with B<-f> and B<-g>, where B<-m> does
not.

=item B<--thpppt>

Display the all-important Bill The Cat logo.  Note that the exact
spelling of B<--thpppppt> is not important.  It's checked against
a regular expression.

=item B<--bar>

Check with the admiral for traps.

=item B<--cathy>

Chocolate, Chocolate, Chocolate!

=back

=head1 THE .ackrc FILE

The F<.ackrc> file contains command-line options that are prepended
to the command line before processing.  Multiple options may live
on multiple lines.  Lines beginning with a # are ignored.  A F<.ackrc>
might look like this:

    # Always sort the files
    --sort-files

    # Always color, even if piping to another program
    --color

    # Use "less -r" as my pager
    --pager=less -r

Note that arguments with spaces in them do not need to be quoted,
as they are not interpreted by the shell. Basically, each I<line>
in the F<.ackrc> file is interpreted as one element of C<@ARGV>.

F<ack> looks in several locations for F<.ackrc> files; the searching
process is detailed in L</"ACKRC LOCATION SEMANTICS">.  These
files are not considered if B<--noenv> is specified on the command line.

=head1 Defining your own types

ack allows you to define your own types in addition to the predefined
types. This is done with command line options that are best put into
an F<.ackrc> file - then you do not have to define your types over and
over again. In the following examples the options will always be shown
on one command line so that they can be easily copy & pasted.

File types can be specified both with the the I<--type=xxx> option,
or the file type as an option itself.  For example, if you create
a filetype of "cobol", you can specify I<--type=cobol> or simply
I<--cobol>.  File types must be at least two characters long.  This
is why the C language is I<--cc> and the R language is I<--rr>.

I<ack --perl foo> searches for foo in all perl files. I<ack --help=types>
tells you, that perl files are files ending
in .pl, .pm, .pod or .t. So what if you would like to include .xs
files as well when searching for --perl files? I<ack --type-add perl:ext:xs --perl foo>
does this for you. B<--type-add> appends
additional extensions to an existing type.

If you want to define a new type, or completely redefine an existing
type, then use B<--type-set>. I<ack --type-set eiffel:ext:e,eiffel> defines
the type I<eiffel> to include files with
the extensions .e or .eiffel. So to search for all eiffel files
containing the word Bertrand use I<ack --type-set eiffel:ext:e,eiffel --eiffel Bertrand>.
As usual, you can also write B<--type=eiffel>
instead of B<--eiffel>. Negation also works, so B<--noeiffel> excludes
all eiffel files from a search. Redefining also works: I<ack --type-set cc:ext:c,h>
and I<.xs> files no longer belong to the type I<cc>.

When defining your own types in the F<.ackrc> file you have to use
the following:

  --type-set=eiffel:ext:e,eiffel

or writing on separate lines

  --type-set
  eiffel:ext:e,eiffel

The following does B<NOT> work in the F<.ackrc> file:

  --type-set eiffel:ext:e,eiffel

In order to see all currently defined types, use I<--help-types>, e.g.
I<ack --type-set backup:ext:bak --type-add perl:ext:perl --help-types>

In addition to filtering based on extension, ack offers additional
filter types.  The generic syntax is
I<--type-set TYPE:FILTER:ARGS>; I<ARGS> depends on the value
of I<FILTER>.

=over 4

=item is:I<FILENAME>

I<is> filters match the target filename exactly.  It takes exactly one
argument, which is the name of the file to match.

Example:

    --type-set make:is:Makefile

=item ext:I<EXTENSION>[,I<EXTENSION2>[,...]]

I<ext> filters match the extension of the target file against a list
of extensions.  No leading dot is needed for the extensions.

Example:

    --type-set perl:ext:pl,pm,t

=item match:I<PATTERN>

I<match> filters match the target filename against a regular expression.
The regular expression is made case-insensitive for the search.

Example:

    --type-set make:match:/(gnu)?makefile/

=item firstlinematch:I<PATTERN>

I<firstlinematch> matches the first line of the target file against a
regular expression.  Like I<match>, the regular expression is made
case insensitive.

Example:

    --type-add perl:firstlinematch:/perl/

=back

=head1 ENVIRONMENT VARIABLES

For commonly-used ack options, environment variables can make life
much easier.  These variables are ignored if B<--noenv> is specified
on the command line.

=over 4

=item ACKRC

Specifies the location of the user's F<.ackrc> file.  If this file doesn't
exist, F<ack> looks in the default location.

=item ACK_OPTIONS

This variable specifies default options to be placed in front of
any explicit options on the command line.

=item ACK_COLOR_FILENAME

Specifies the color of the filename when it's printed in B<--group>
mode.  By default, it's "bold green".

The recognized attributes are clear, reset, dark, bold, underline,
underscore, blink, reverse, concealed black, red, green, yellow,
blue, magenta, on_black, on_red, on_green, on_yellow, on_blue,
on_magenta, on_cyan, and on_white.  Case is not significant.
Underline and underscore are equivalent, as are clear and reset.
The color alone sets the foreground color, and on_color sets the
background color.

This option can also be set with B<--color-filename>.

=item ACK_COLOR_MATCH

Specifies the color of the matching text when printed in B<--color>
mode.  By default, it's "black on_yellow".

This option can also be set with B<--color-match>.

See B<ACK_COLOR_FILENAME> for the color specifications.

=item ACK_COLOR_LINENO

Specifies the color of the line number when printed in B<--color>
mode.  By default, it's "bold yellow".

This option can also be set with B<--color-lineno>.

See B<ACK_COLOR_FILENAME> for the color specifications.

=item ACK_PAGER

Specifies a pager program, such as C<more>, C<less> or C<most>, to which
ack will send its output.

Using C<ACK_PAGER> does not suppress grouping and coloring like
piping output on the command-line does, except that on Windows
ack will assume that C<ACK_PAGER> does not support color.

C<ACK_PAGER_COLOR> overrides C<ACK_PAGER> if both are specified.

=item ACK_PAGER_COLOR

Specifies a pager program that understands ANSI color sequences.
Using C<ACK_PAGER_COLOR> does not suppress grouping and coloring
like piping output on the command-line does.

If you are not on Windows, you never need to use C<ACK_PAGER_COLOR>.

=back

=head1 AVAILABLE COLORS

F<ack> uses the colors available in Perl's L<Term::ANSIColor> module, which
provides the following listed values. Note that case does not matter when using
these values.

=head2 Foreground colors

    black  red  green  yellow  blue  magenta  cyan  white

    bright_black  bright_red      bright_green  bright_yellow
    bright_blue   bright_magenta  bright_cyan   bright_white

=head2 Background colors

    on_black  on_red      on_green  on_yellow
    on_blue   on_magenta  on_cyan   on_white

    on_bright_black  on_bright_red      on_bright_green  on_bright_yellow
    on_bright_blue   on_bright_magenta  on_bright_cyan   on_bright_white

=head1 ACK & OTHER TOOLS

=head2 Simple vim integration

F<ack> integrates easily with the Vim text editor. Set this in your
F<.vimrc> to use F<ack> instead of F<grep>:

    set grepprg=ack\ -k

That example uses C<-k> to search through only files of the types ack
knows about, but you may use other default flags. Now you can search
with F<ack> and easily step through the results in Vim:

  :grep Dumper perllib

=head2 Editor integration

Many users have integrated ack into their preferred text editors.
For details and links, see L<https://beyondgrep.com/more-tools/>.

=head2 Shell and Return Code

For greater compatibility with I<grep>, I<ack> in normal use returns
shell return or exit code of 0 only if something is found and 1 if
no match is found.

(Shell exit code 1 is C<$?=256> in perl with C<system> or backticks.)

The I<grep> code 2 for errors is not used.

If C<-f> or C<-g> are specified, then 0 is returned if at least one
file is found.  If no files are found, then 1 is returned.

=cut

=head1 DEBUGGING ACK PROBLEMS

If ack gives you output you're not expecting, start with a few simple steps.

=head2 Try it with B<--noenv>

Your environment variables and F<.ackrc> may be doing things you're
not expecting, or forgotten you specified.  Use B<--noenv> to ignore
your environment and F<.ackrc>.

=head2 Use B<-f> to see what files have been selected for searching

Ack's B<-f> was originally added as a debugging tool.  If ack is
not finding matches you think it should find, run F<ack -f> to see
what files have been selected.  You can also add the C<--show-types>
options to show the type of each file selected.

=head2 Use B<--dump>

This lists the ackrc files that are loaded and the options loaded
from them.  You may be loading an F<.ackrc> file that you didn't know
you were loading.

=head1 ACKRC LOCATION SEMANTICS

Ack can load its configuration from many sources.  The following list
specifies the sources Ack looks for configuration files; each one
that is found is loaded in the order specified here, and
each one overrides options set in any of the sources preceding
it.  (For example, if I set --sort-files in my user ackrc, and
--nosort-files on the command line, the command line takes
precedence)

=over 4

=item *

Defaults are loaded from App::Ack::ConfigDefaults.  This can be omitted
using C<--ignore-ack-defaults>.

=item * Global ackrc

Options are then loaded from the global ackrc.  This is located at
C</etc/ackrc> on Unix-like systems.

Under Windows XP and earlier, the global ackrc is at
C<C:\Documents and Settings\All Users\Application Data\ackrc>

Under Windows Vista/7, the global ackrc is at
C<C:\ProgramData\ackrc>

The C<--noenv> option prevents all ackrc files from being loaded.

=item * User ackrc

Options are then loaded from the user's ackrc.  This is located at
C<$HOME/.ackrc> on Unix-like systems.

Under Windows XP and earlier, the user's ackrc is at
C<C:\Documents and Settings\$USER\Application Data\ackrc>.

Under Windows Vista/7, the user's ackrc is at
C<C:\Users\$USER\AppData\Roaming\ackrc>.

If you want to load a different user-level ackrc, it may be specified
with the C<$ACKRC> environment variable.

The C<--noenv> option prevents all ackrc files from being loaded.

=item * Project ackrc

Options are then loaded from the project ackrc.  The project ackrc is
the first ackrc file with the name C<.ackrc> or C<_ackrc>, first searching
in the current directory, then the parent directory, then the grandparent
directory, etc.  This can be omitted using C<--noenv>.

=item * --ackrc

The C<--ackrc> option may be included on the command line to specify an
ackrc file that can override all others.  It is consulted even if C<--noenv>
is present.

=item * ACK_OPTIONS

Options are then loaded from the environment variable C<ACK_OPTIONS>.  This can
be omitted using C<--noenv>.

=item * Command line

Options are then loaded from the command line.

=back

=head1 BUGS & ENHANCEMENTS

ack is based at GitHub at L<https://github.com/beyondgrep/ack3>

Please report any bugs or feature requests to the issues list at
Github: L<https://github.com/beyondgrep/ack3/issues>.

Please include the operating system that you're using; the output of
the command C<ack --version>; and any customizations in your F<.ackrc>
you may have.

To suggest enhancements, please submit an issue at
L<https://github.com/beyondgrep/ack3/issues>.  Also read the
F<DEVELOPERS.md> file in the ack code repository.

Also, feel free to discuss your issues on the ack mailing
list at L<https://groups.google.com/group/ack-users>.

=head1 SUPPORT

Support for and information about F<ack> can be found at:

=over 4

=item * The ack homepage

L<https://beyondgrep.com/>

=item * Source repository

L<https://github.com/beyondgrep/ack3>

=item * The ack issues list at Github

L<https://github.com/beyondgrep/ack3/issues>

=item * The ack announcements mailing list

L<http://groups.google.com/group/ack-announcement>

=item * The ack users' mailing list

L<http://groups.google.com/group/ack-users>

=item * The ack development mailing list

L<http://groups.google.com/group/ack-users>

=back

=head1 COMMUNITY

There are ack mailing lists and a Slack channel for ack.  See
L<https://beyondgrep.com/community/> for details.

=head1 ACKNOWLEDGEMENTS

How appropriate to have I<ack>nowledgements!

Thanks to everyone who has contributed to ack in any way, including
H.Merijn Brand,
Duke Leto,
Gerhard Poul,
Ethan Mallove,
Marek Kubica,
Ray Donnelly,
Nikolaj Schumacher,
Ed Avis,
Nick Morrott,
Austin Chamberlin,
Varadinsky,
SE<eacute>bastien FeugE<egrave>re,
Jakub Wilk,
Pete Houston,
Stephen Thirlwall,
Jonah Bishop,
Chris Rebert,
Denis Howe,
RaE<uacute>l GundE<iacute>n,
James McCoy,
Daniel Perrett,
Steven Lee,
Jonathan Perret,
Fraser Tweedale,
RaE<aacute>l GundE<aacute>n,
Steffen Jaeckel,
Stephan Hohe,
Michael Beijen,
Alexandr Ciornii,
Christian Walde,
Charles Lee,
Joe McMahon,
John Warwick,
David Steinbrunner,
Kara Martens,
Volodymyr Medvid,
Ron Savage,
Konrad Borowski,
Dale Sedivic,
Michael McClimon,
Andrew Black,
Ralph Bodenner,
Shaun Patterson,
Ryan Olson,
Shlomi Fish,
Karen Etheridge,
Olivier Mengue,
Matthew Wild,
Scott Kyle,
Nick Hooey,
Bo Borgerson,
Mark Szymanski,
Marq Schneider,
Packy Anderson,
JR Boyens,
Dan Sully,
Ryan Niebur,
Kent Fredric,
Mike Morearty,
Ingmar Vanhassel,
Eric Van Dewoestine,
Sitaram Chamarty,
Adam James,
Richard Carlsson,
Pedro Melo,
AJ Schuster,
Phil Jackson,
Michael Schwern,
Jan Dubois,
Christopher J. Madsen,
Matthew Wickline,
David Dyck,
Jason Porritt,
Jjgod Jiang,
Thomas Klausner,
Uri Guttman,
Peter Lewis,
Kevin Riggle,
Ori Avtalion,
Torsten Blix,
Nigel Metheringham,
GE<aacute>bor SzabE<oacute>,
Tod Hagan,
Michael Hendricks,
E<AElig>var ArnfjE<ouml>rE<eth> Bjarmason,
Piers Cawley,
Stephen Steneker,
Elias Lutfallah,
Mark Leighton Fisher,
Matt Diephouse,
Christian Jaeger,
Bill Sully,
Bill Ricker,
David Golden,
Nilson Santos F. Jr,
Elliot Shank,
Merijn Broeren,
Uwe Voelker,
Rick Scott,
Ask BjE<oslash>rn Hansen,
Jerry Gay,
Will Coleda,
Mike O'Regan,
Slaven ReziE<0x107>,
Mark Stosberg,
David Alan Pisoni,
Adriano Ferreira,
James Keenan,
Leland Johnson,
Ricardo Signes,
Pete Krawczyk and
Rob Hoelz.

=head1 AUTHOR

Andy Lester, C<< <andy at petdance.com> >>

=head1 COPYRIGHT & LICENSE

Copyright 2005-2018 Andy Lester.

This program is free software; you can redistribute it and/or modify
it under the terms of the Artistic License v2.0.

See http://www.perlfoundation.org/artistic_license_2_0 or the LICENSE.md
file that comes with the ack distribution.

=cut

1;
package App::Ack::Docs::FAQ;

=pod

=head1 FAQ

This is the Frequently Asked Questions list for ack.  You can also see the
manual in the Perl module App::Ack::Docs::Manual, or running F<ack --man>.

=head2 Can I stop using grep now?

Many people find I<ack> to be better than I<grep> as an everyday tool
99% of the time, but don't throw I<grep> away, because there are times
you'll still need it.  For example, you might be looking through huge
log files and not using regular expressions.  In that case, I<grep>
will probably perform better.

=head2 Why isn't ack finding a match in (some file)?

First, take a look and see if ack is even looking at the file.  ack is
intelligent in what files it will search and which ones it won't, but
sometimes that can be surprising.

Use the C<-f> switch, with no regex, to see a list of files that ack
will search for you.  If your file doesn't show up in the list of files
that C<ack -f> shows, then ack never looks in it.

=head2 Wouldn't it be great if F<ack> did search & replace?

No, ack will always be read-only.  Perl has a perfectly good way
to do search & replace in files, using the C<-i>, C<-p> and C<-n>
switches.

You can certainly use ack to select your files to update.  For
example, to change all "foo" to "bar" in all PHP files, you can do
this from the Unix shell:

    $ perl -i -p -e's/foo/bar/g' $(ack -f --php)

=head2 Can I make ack recognize F<.xyz> files?

Yes!  Please see L</"Defining your own types"> in the ack manual.

=head2 Will you make ack recognize F<.xyz> files by default?

We might, depending on how widely-used the file format is.

Submit an issue at in the GitHub issue queue at
L<https://github.com/beyondgrep/ack3/issues>.  Explain what the file format
is, where we can find out more about it, and what you have been using
in your F<.ackrc> to support it.

Please do not bother creating a pull request.  The code for filetypes
is trivial compared to the rest of the process we go through.

=head2 Why is it called ack if it's called ack-grep?

The name of the program is "ack".  Some packagers have called it
"ack-grep" when creating packages because there's already a package
out there called "ack" that has nothing to do with this ack.

I suggest you make a symlink named F<ack> that points to F<ack-grep>
because one of the crucial benefits of ack is having a name that's
so short and simple to type.

To do that, run this with F<sudo> or as root:

   ln -s /usr/bin/ack-grep /usr/bin/ack

Alternatively, you could use a shell alias:

    # bash/zsh
    alias ack=ack-grep

    # csh
    alias ack ack-grep

=head2 What does F<ack> mean?

Nothing.  I wanted a name that was easy to type and that you could
pronounce as a single syllable.

=head2 Can I do multi-line regexes?

No, ack does not support regexes that match multiple lines.  Doing
so would require reading in the entire file at a time.

If you want to see lines near your match, use the C<--A>, C<--B>
and C<--C> switches for displaying context.

=head2 Why is ack telling me I have an invalid option when searching for C<+foo>?

ack treats command line options beginning with C<+> or C<-> as options; if you
would like to search for these, you may prefix your search term with C<--> or
use the C<--match> option.  (However, don't forget that C<+> is a regular
expression metacharacter!)

=head2 Why does C<"ack '.{40000,}'"> fail?  Isn't that a valid regex?

The Perl language limits the repetition quantifier to 32K.  You
can search for C<.{32767}> but not C<.{32768}>.

=head2 Ack does "X" and shouldn't, should it?

We try to remain as close to grep's behavior as possible, so when in
doubt, see what grep does!  If there's a mismatch in functionality there,
please submit an issue to GitHub, and/or bring it up on the ack-users
mailing list.

=cut

1;
package App::Ack::Docs::Cookbook;

=head1 COOKBOOK

Here are examples of how to effectively use ack.

Note: on Windows CMD prompt, the quoting may need to switch C<"> for C<'> and/or vice-versa.


=head1 COMPOUND QUERIES

Some compound queries can be done in a single RE pattern but most will require a pipeline command.

=head2 Find "goat(s)" or "cow(s)" or both

    ack '(goats?|cows?)'

=head2 Find "goats" in every file that also contains "cows"

Use command substitution to pass a list of cow files to ack:

    ack goats $(ack -l cows)

Or you can use the program F<xargs> to feed the filenames to the
goat search.

    ack -l cows | xargs ack goats

Or you can use ack's C<-x> option to do the same thing without
having to get F<xargs> involved.

    ack -l cows | ack -x goats

=head2 Find goats in files that do not contain cows

    ack -L cows | ack -x -l goats

=head2 Find "goats" in every farmish file

One of the usual FAQ is how do I use C<< -f pattern1 >> for files
and C< pattern2 > within the files in one command?

The answer is don't, use two C<ack>s, either via a Pipe, or nest them.

   ack -ig 'farm|(?:ei)+o$' | ack -x goats

   ack goats $(ack -ig 'farm|(?:ei)+o$' )

=head2 Find "goats" and "cows" in the same line, either order, as words

Following the  compound is a pipeline trope,
if we assume filenames don't also have goats -

   ack  cows | ack goats

This obviously could scale to N terms, at the cost of N processes.

But for just two, we can easily do it in on go, too:

    ack '\bgoats\b.*\bcows\b|\bcows\b.*\bgoats\b'

C<|> says "OR".

C<< \b >> says word boundary here, letters one side and space or punctuation on the other,
so half of a Whole-words limitation.

C<.*> says anything or nothing, but wrapped in C<\b.*\b> with words on outsides,
will have space or punctuation first and last, unless nothing -- and nothing isn't
allowed, need at least a single space or comma, not C<goatscows>.

=head2 Search for all the files that mention Sys::Hostname but don't match hostname.

    ack -l Sys::Hostname | ack -x -L -I hostname

(We added C<-I> (the reverse of C<-i> or C<< --ignore-case >>)
because we have C<< --smart-case >> on in our C<.ackrc>.
The first C<ack> doesn't need it because smart-case smartly goes case-sensitive when pattern has some UpperCase.
We could have typed C<< --no-smart-case >> but that's too much to type,
so C<-I> on commandline, longform in scripts!)


=head2 Find all goat(s) in files without cows

Search all the files that don't have cow(s) and show their goat(s).

    ack -L 'cows?' | ack -x -w 'goats?'

=head2  Search and highlight a specific pattern 'goat' but exclude lines that match also another pattern 'cow'.

    ack '^(?!.*?cow).*?\Kgoat'

The C<\K> is called KEEP; aside from preventing backtracking, it resets the C<$` $&> boundary, the start of match.
C<(?!.*cow)> is a negative lookahead.
C<.*?> is non-greedy so the search is left to right.

=head2 Simulate a 'to within 5 lines' adverb

     ack -w "$1" -C$n  $dirs | ack -C$n -w "$2" | ack -C$n "$1|$2" --pager='less -r'

Add a C<-h> etc to taste.

=head1 USING ACK EFFECTIVELY

=head2 Use the F<.ackrc> file.

The F<.ackrc> is the place to put all your options you use most of
the time but don't want to remember.  Put all your C<--type-add>
and C<--type-set> definitions in it.  If you like C<--smart-case> and
C<--sort-files>, set them there, too.


=head2 Use F<-f> for working with big codesets

Ack does more than search files.  C<ack -f --perl> will create a
list of all the Perl files in a tree, ideal for sending into F<xargs>.
For example:

    # Change all "this" to "that" in all Perl files in a tree.
    ack -f --perl | xargs perl -p -i -e's/this/that/g'

or if you prefer:

    perl -p -i -e's/this/that/g' $(ack -f --perl)

=head2 Use C<-Q> when in doubt about metacharacters

If you're searching for something with a regular expression
metacharacter, most often a period in a filename or IP address, add
the C<-Q> to avoid false positives without all the backslashing.  See
the following example for more...

=head2 Use ack to watch log files

Here's one I used the other day to find trouble spots for a website
visitor.  The user had a problem loading F<troublesome.gif>, so I
took the access log and scanned it with ack twice.

    ack -Q aa.bb.cc.dd /path/to/access.log | ack -Q -B5 troublesome.gif

The first ack finds only the lines in the Apache log for the given
IP.  The second finds the match on my troublesome GIF, and shows
the previous five lines from the log in each case.

=head2 Use ack instead of find

    ack -f --html --print0 | xargs -0 wc -l

(You may omit the C<< --print0 >> and C<-0> if none of your files or directories contain a space in the name.)

=head2 Searching for a method call

    ack -- '->method'

or

    ack '[-]>method'

(Optionally followed by "word boundary" marker C<\b>
as in  C<< [-]>method\b >> to not find C<< ->methodically >> .)

=head2 Use C<-w> only for words

C<ack -w pattern> will restrict the match to C<pattern> as a word, surrounded by whitespace or punctuation
(and both ends of lines count as whitespace).
(Word means alphabetic or '_' in this context.
If your OS tells Perl that certain accented characters are alphabetic for you, they may be included, try it!)

If your desired pattern begins with one word and ends with another, C<-w> is still safe.

If your desired pattern starts or ends (or both) with punctuation, using C<-w> may be erroneous.  ack will warn you in this case.
If you get a warning about C<-w>, Say What You Mean (SWYM).
If you mean the start of your pattern with punctuation should be
at the beginning of line B<OR> preceded by a word OR by a space (or tab etc), before the needed punctuation,
SWYM as C<(?:^|\b|\s)#+\s+(.*)>
which will find and capture a comment.
(Try it plain, with C<-o>, and with C<--output='$1'>, which has its own section below)

So, don't look for C<ack -w '$identifier'>, as it won't match
C<+$identifier> or C<func($identifier)> and won't even find it in column
1.  Instead, do:

   ack '(?:^|\s|\b)\$identifier\b'

   ack '(?x)(?: ^ | \b | (?<=  \W | \s  )) [#]  DEBUG (?= \b | \s | $) '

SWYMingly finds C<< #DEBUG >> if at beginning of line, after a word break, a non-word char, or a space char,
and followed by a word-break, or space, or end-of-line.
This uses look-behind and look-ahead so that only B<#DEBUG> is highlighted (or saved to C<$&>),
and also C<(?x)> the B<extended> syntax, in which whitespace is only match if explicitly C<\s> or C<\0x20> or C<[ ]>,
the blanks are for readability.

(This is over-specified, since C<G> followed by space would be C<\b>, and C<\s> is C<\W>, but if you're not sure, it's OK to over-specify!)

=head2 See all the C<.vim> files in your hidden C<~/.vim> directory, except in the C<bundle/> directory.

    ack -f --vim ~/.vim --ignore-dir=bundle

=head2 Find all the Ruby files that match /tax/.

   ack -g tax --ruby

Open all the files that have taxes in them.

   vim $(ack -l taxes)

=head2 Find all the Perl test files and test them

Use C<ack>'s file-type inference to find things of C<--type=perltest>
and feed them to C<xargs> so it will run the C<prove> command on them.

     ack -f --perltest | xargs prove

=head2 Find places where two methods with the same name are being called on the same line.

    ack -- '->(\w+).*->\1\b'

The C<< (\w+) >> captures a method name (introduced by C<< -> >> ),
which is then sought a second time as C<\1>, a backreference.
The backreference needs a trailing C<\b> so C<< ->method ... ->methodically >> does not match.
The C<< (\w+) >> needs neither left nor right side C<\b> because the C<+> modifier is greedy, will take all the word chars available.

=head2 Find all the places in code there's a call like C<< sort { lc $a cmp lc $b } >>.

This is a rough heuristic.  It gets false positives, but it's pretty useful.

    ack '\bsort\b.+(\w+).+\bcmp\b.+\b(\1)\b'

The word and backreference are matching the canonicalizing use of C<lc> to lowercase both comparands.

=head2 Show a range of lines in a file

     ack --lines=830-850 filename

And use C<-H> to show what line numbers are.

=head2 Find files that match one string but do not match another.

The module Test::Warn has a number of functions of the form
C<warnings_xxx>.  Look in all the files that find Test::Warn but don't
find the C<warnings_xxx> functions.

    ack -L 'warnings?_' $(ack -l Test::Warn)

=head2 Search only recently changed or 'dirty' files

Most version control systems provide a query to list files changed since checkout, often referred to as 'dirty' files. E.g.,

    alias dirty="git diff --name-only"

    dirty | ack -x pattern

or

    ack pattern $(dirty)

=head2 See just outline of POD in Perl files

    perldoc -o markdown lib/App/Ack/Docs/Cookbook.pm | ack -h '^#+'

Note, this requires L<Pod::Markdown|https://metacpan.org/pod/Pod::Markdown> plugin installed.

=head2 TBD Do we need more C<-f> and C<-g> examples?

#TODO

=head1 EXAMPLES OF C<< --output >>

The C<-o> and C<< --output expr >> options allow for specifying and formating the output.

With look-behind and look-ahead, one "match without matching" for highlighting or C<-o>) purposes.
The  regex C<< abc\K(def)(?=ghi) >>  will highlight ONLY C<def> in the text, \
but only if that string is preceeded by C<abc> and C<ghi> follows.
With C<-o>, it will output C<def> but only when found in context of C<abc>B<<C<def>>>C<ghi>.

HT to L<HN|https://news.ycombinator.com/item?id=15433310>

=head2 Inventory all PHP sqldo functions

Simple C<-o> requests output only what is matched.

    ack 'sqldo_\w+' --php -o -h | sort -u

=head2 Look for a method you're not sure of the name of.

I was looking for a method that I knew was called "something_follows",
so I looked for method invocations like that:

     ack -- '->.+_follows\b'


=head2 Variables for C<< --output >>

Following variables are useful in the expansion string:

=over 4

=item C<$&>

The whole string matched by PATTERN.

=item C<$1>, C<$2>, ... C<$9>

The contents of the 1st, 2nd ... bracketed group in PATTERN.

=item C<$`>

The string before (to the left of) the match.

=item C<$'>

The string after (to the right of) the match.

=back

For more details and other variables see
L<http://perldoc.perl.org/perlvar.html#Variables-related-to-regular-expressions|perlvar>.

This example shows how to add text around a particular pattern
(in this case adding _ around word with "e")

    ack3 "\w*e\w*" quick.txt --output="$`_$&_$'"
    _The_ quick brown fox jumps over the lazy dog
    The quick brown fox jumps _over_ the lazy dog
    The quick brown fox jumps over _the_ lazy dog

This shows how to pick out particular parts of a match using ( ) within regular expression.

    ack '=head(\d+)\s+(.*)' --output=' $1 : $2'
    input file contains "=head1 NAME"
    output  "1 : NAME"

=head2 Find all the headers used in your C programs.

    ack '#include\s+<(.+)>' --cc --output='$1' | sort -u

=head2 Find the most-used modules in your codebase.

    ack '^use ([\w+:]+)' --output='$1' -h --nogroup | sort | uniq -c | sort -n

=head2 Find all the subroutines in Perl tests and then give a count of how many of each there are

     ack '^sub (\w+)' --perltest --output='$1' -h --nogroup | sort | uniq -c | sort -n

=head2 In COBOL source code, match only lines with blank in column 7, ignore

    ack '^.{6}[ ].*?\Kpattern'
    ack '(?x) ^ .{6} [ ] .*? \K pattern'  # same but readable

Again using the C<\K> Keep to reset start of matching.

(Legacy COBOL put C<'*'> in Col 7 for comments, back in punch-card days.
FORTRAN in the day similarly used 'C' or '*' in Col 1.
Early FORTRAN wrapped lines with C<&> in Col 73 and in Col 6 of next line.)

(Hat-tip for Question to Pierre)

=head2 Extract part of a line from a logfile

    ack '>>ip(\S+).+rq"/help' --output='$1' -h

## Fake parsing long JSON

Having a very long line of JSON consisting of bits like

    {"city":"london","first name":"peter","last name":"hansen","age":"40"},
    {"city":"new york","first name":"celine","last name":"parker","age":"36"]

wanting output like

     peter (40) celine (36)

the right way would be to do this is the L<C<jq>|https://stedolan.github.io/jq/> utility - which is sed or ack for JSON. Or write a program. However ... this example, ack can do it.

The sneaky and potentially unreliable way to do it is:

     ack '"first name":"([^"]+)".+"age":"(\d+)"' input.txt --output='$1 $2'

Why unreliable? JSON like Perl makes no guarantee hash keys are in any particular order.

For only two fields, we can use 'alternation' to make it safe:

     ack --output '$1$4($2$3)' '{.*?"first name":"([^"]*)".*?age":"(\d+)|{.*?"age":"(\d+)".*?first name":"([^"]*?)"'

This won't scale well to 3! or greater possible field orders to extract.
At which point, plain Perl with any real JSON module is required.

HT L<SO|https://stackoverflow.com/questions/45538755/bash-text-extracting>

=head1 VERY ELEGANT ACK

=head2 Open list of matching files in Vim, searching for your search term

     $ ack my_search_term
     <results>
     $ vim $(!! -l) +/!$

=over 4

=item C<!!> expands to the previous command - C<ack my_search_term> in the example

=item C<$(...)> expands to the output of the command in the parens, so the output of C<ack my_search_term -l> in the example

=item C<<  +/<term> >> tells Vim to start searching for C<< <term> >> once it opens

=item C<< !$ >> expands to the last argument of the previous command - my_search_term in the example

=back

Small caveat: Vim patterns and Perl regexes have some overlap, but they are different, so this doesn't work
so well when you have a more complex regex as your search term.
Vim command C<< :help perl-patterns >> will report what Vim thinks the differences are.

=head2 Extending ack your way

A user who really wants the working directory reported makes a C<bash function> (which will look like an alias) to make it so. Hat tip to B<teika-kazura> !

    function ack(){
        local ackLogDir=/tmp/mylogs/Ack
        mkdir -p "$ackLogDir"
        chmod 777 "$ackLogDir" &> /dev/null
        if [[ $# == 0 ]]; then
            find "$ackLogDir" -type f | xargs ls -t |xargs less
            return
        fi
        local f="$( mktemp --tmpdir=$ackLogDir )"
        echo "# Pwd: `pwd`" > $f
        echo "# ack $@" >> $f
        command ack "$@" >> "$f" 2>&1
        less $f
    }

(We can't really recommend C<chmod 777>.  You're better off with per-user temp sub-dirs for security safety,
whether under C<$HOME> or under C</tmp/$USER>.)

=head2 Find log lines with 4 nulls and sort by IP address

Via the L<@clmagic|https://twitter.com/clmagic> "Command Line Magic" Twitter account:

    egrep -- "\t-\t-\t-\t-\t" entries.txt |sort -k3V
    # Get the entries with 4+ null fields and sort the entries by IPv4 (-V) in the 3rd column.

(It's 4+ B<adjacent> null tab-separated fields, null represented as dashes.)

C<ack> will happily do likewise, no changes:

    ack -- "\t-\t-\t-\t-\t" entries.txt |sort -k3V

The difference with C<ack> being, you can use the larger C<perldoc perlre> pattern language,
larger than even C<egrep>'s, to better SWYM DRY (Say What You Mean, and Don't Repeat Yourself):

    ack -- "(?x: \t  (?: - \t ){4} )" entries.txt |sort -k3V

to explicitly count (C<< (?:  ){4} >>) the tab-separated dashes.
The C<< (?x: ) >>  says spaces don't count, are used for readability.
If 'null' was optional spaces between the tabs not a single dash,
we'd use a character class of just space C<< [ ] >>:

    ack -- "(?x: \t  (?: [ ]* \t ){4} )" entries.txt |sort -k3V

(We could use a C<\ > escaped space, but that's hard to read, especially hard to tell if wrong.
Is that one space or two there?)

(L<regex cheatsheat comparing ack's perlRe with (e)grep, sed, ...|https://remram44.github.io/regex-cheatsheet/regex.html>

=head2 Summarize the file-types in your project

    $ ack --noenv --show-type -f | perl -MData::Dumper -naE'++$n{$F[-1]}; END {print Dumper \%n}'
    $VAR1 = {
          'xml' => 32,
          'sql' => 2,
          'shell' => 4,
          'php,shell' => 8,
          'yaml' => 1809,
          'php' => 7122,
          'css' => 360,
          'markdown' => 7,
          'html' => 7,
          '=>' => 1180,
          'json' => 69,
          'js' => 582
        };

=head2 Fetching URLs with ack

In old C<ack2>, Mark Fowler demonstrated the reason that ack3 no longer allows C<--output>
in project-scoped F<.ackrc> files.

In the PerlAdvent calendar
(L<http://www.perladvent.org/2014/2014-12-21.html>), Mark wrote an ack
expression to annotate the URLs found in a file with their download
weights:

    ack2 --output='$&: @{[ eval "use LWP::Simple; 1" && length LWP::Simple::get($&) ]} bytes' \
           'https?://\S+' list.txt
    http://google.com/: 19529 bytes
    http://metacpan.org/: 7560 bytes
    http://www.perladvent.org/: 5562 bytes

C<ack3> restricts C<--output> to using only the safe and sensible variables documented,
and emphatically not code execution via array interpolation.

But you can sill do this, it just requires a pipe --

    ack -o 'https?://\S+' DEVELOPERS.md  \
    |  perl -nl -MLWP::Simple \
                -E 'say "$_ :  @{[ length LWP::Simple::get($_) ]}  bytes";'
    https://github.com/beyondgrep/website :  50784  bytes
    https://github.com/beyondgrep/ack3/issues :  111627  bytes

=head2 KWIC: KeyWord in Context index

A Keyword In Context (KWIC) index was more useful in the days of offline
computing and line-printer reports but is still sometimes relevant to
see the matches not (just) highlighted but lined up for easy scanning.

The traditional distinction between KWIC and KWOC is whether the Keyword
is at start of line with it's left context wrapped (KWOC= Out of), or
tab-separated in the middle. KWIC works best with two word-processor
fixed tabsets, not with 8-char tabs, alas.

    ack  --output '$&^I$'"'"'^I|| $`' pattern files | sort     # KWOC
    ack  --output '$&^I$\'^I|| $`'    pattern files | sort     # KWOC

    ack  --output '$`^I$&^I$'"'" pattern files | sort -df -t^I -k F2,F2 # pseudo KWIC
    ack  --output '$`^I$&^I$\''  pattern files | sort -df -t^I -k F2,F2 # pseudo KWIC

(On the KWOC, the C<||> shows where right and left margin are wrapped.)
(To make the KWIC output look right, load into OpenOffice or Word to spread the tab stops !)


=head2 TBD Add Elegant nearly- and not-ugly-and- exact solutions that  require neither hypothetical, C<\n> as OR nor C<--fgrep-f> .

Ack doesn't have C<--fgrep-f> nor does it accept newlines as OR otherwise, as newer Grep does.  But Grep has no C<--passthru>. 
L<Requestor|> would like to view the whole files but highlight any of several words in each, which needs both.
Workaround is ugly:

  ack /etc --match "`/bin/ls /home/ | tr '\n' '|' | sed -e 's/|$//'`" 

Longer but more readable, use C<< $() >> instead of C<``> and Perl instead of tr, sed, 
which allows us to insert C<< | >> between as needed without an extra to be removed:

  ack /etc --match $(/bin/ls /home/ | perl  -E '@u=<>; chomp for @u; say join q(|), @u' )

or invert the C<ls>,

  ack /etc --match $( perl -E '@u=`ls /home/`; chomp for @u; say join q(|), @u' )

or keep it in one process, 

  ack /etc --match $( perl -E 'chdir q(/home/); @u=<*>; chomp for @u; say join q(|), @u' )

# TODO https://github.com/beyondgrep/ack2/pull/646

=head2 TBD look-ahead and look-behind

#TODO There are a couple examples above - do we need more ?

=head1 WHEN TO DO SOMETHING ELSE

Sometimes tools in the B<BeyondGrep> family aren't the right tool.

=head2 Json Query C<jq>)

For commandline access to JSON data, L<C<jq>|https://stedolan.github.io/jq/> is utility,
it's like C<sed> or C<ack> for JSON.

=head2 C<comm>: Lines (words) in file1 but not in file2

(Commonly the lines are single words per line.)

While grep can do this

    grep -F -x -v -f file1 file2 > file3

it's rather slow for large files!

The standard Unix/Linux tool for this is C<comm>.
In C<comm> terms, the request is the C<<comm -23 file1 file2>> option.
Wit no args, Column 1 is words only in file1, Columnn 2 is words only in file2,
and Column 3 is words in both files 1 and 2.

The Mnemonic such as it is: C<-23> is C<minus 2,3>,
i.e. omit columns 2 (file 2 words) and 3 (both files words).

One requirement for C<comm> is that files must be sorted by natural sort order.
If the files aren't in nor wanted in sorted order, the shell command or alias needed is

     comm -23 <(sort $file1) <(sort $file2)

with modern C<bash>'s C<< <() >> command substitution as file-pipes.

(That C<< <(fileter $f1) <(filter $f2) >> idiom is also good for pre-filtering input to C<diff> etc.)

Note for Windows users: MicroSoft and CygWin both provide Linux/GNU commandline utilities for Windows.
They may have come with the Perl you're using for Ack.

=cut;

1;