sub switch_to {
    my ( $self, $dist, $alias ) = @_;

    die "Cannot use for alias something that starts with 'perl-'\n"
      if $alias && $alias =~ /^perl-/;

    die "${dist} is not installed\n" unless -d joinpath($self->root, "perls", $dist);

    if ($self->env("PERLBREW_BASHRC_VERSION")) {
        local $ENV{PERLBREW_PERL} = $dist;
        my $HOME = $self->env('HOME');
        my $pb_home = $self->env("PERLBREW_HOME") || $PERLBREW_HOME;

        mkpath($pb_home);
        system("$0 env $dist > " . joinpath($pb_home, "init"));

        print "Switched to $dist.\n\n";
    }
    else {
        $self->launch_sub_shell($dist);
    }
}
##</code><code>##

        # The user does not source bashrc/csh in their shell initialization.
        $env{PATH}    = $env{PERLBREW_PATH}    . ":" . join ":", grep { !/$root\/bin/ } split ":", $ENV{PATH};
        $env{MANPATH} = $env{PERLBREW_MANPATH} . ":" . join ":", grep { !/$root\/man/ }
            ( defined($ENV{MANPATH}) ? split(":", $ENV{MANPATH}) : () );

##</code><code>##

sub installed_perls {
    my $self    = shift;

    my @result;
    my $root = $self->root;

    for (<$root/perls/*>) {
        my ($name) = $_ =~ m/\/([^\/]+$)/;
        my $executable = joinpath($_, 'bin', 'perl');
        my $version_file = joinpath($_,'.version');
        my $orig_version;
        if ( -e $version_file ){
            open my $fh, '<', $version_file;
            local $/;
            $orig_version = <$fh>;
            chomp $orig_version;
        } else {
            $orig_version = `$executable -e 'print \$]'`;
            if ( defined $orig_version and length $orig_version ){
                if (open my $fh, '>', $version_file ){
                    print {$fh} $orig_version;
		}
            }
        }

        push @result, {
            name        => $name,
            orig_version=> $orig_version,
            version     => $self->format_perl_version($orig_version),
            is_current  => ($self->current_perl eq $name) && !($self->current_lib),
            libs => [ $self->local_libs($name) ],
            executable  => $executable
        };
    }

    return sort { $a->{orig_version} <=> $b->{orig_version} or $a->{name} cmp $b->{name}  } @result;
}

##</code><code>##

    for (<$root/perls/*>) {
    my @libs = map { substr($_, length($PERLBREW_HOME) + 6) } <$PERLBREW_HOME/libs/*>;
        @perls = map { m{/([^/]+)$} } grep { -d $_ && ! -l $_ } <$root/perls/*>;
        for my $executable (<$root/perls/$perl/bin/*>) {
    my @build_dirs = <$root/build/*>;
    my @tarballs = <$root/dists/*>;
    my $executable = joinpath($self->root, "perls", $name, "bin", "perl");
    mkpath($_) for (grep { ! -d $_ } map { joinpath($self->root, $_) } qw(perls dists build etc bin));
    my $etc_dir = joinpath($self->root, "etc");
    my $root_dir = $self->path_with_tilde($self->root);
    my $target = joinpath($self->root, "bin", "perlbrew");
    mkpath( joinpath($self->root, "bin" ));
    my $dist_tarball_path = joinpath($self->root, "dists", $dist_tarball);
    my $extracted_dir = "@{[ $self->root ]}/build/$dist_tarball_basename";
    my $extract_command = "cd @{[ $self->root ]}/build; $tarx $dist_tarball";
    my $dist_tarball_path = joinpath($self->root, "dists", $dist_tarball);
    my $build_dir = joinpath($self->root, "build");
    my $dist_extracted_dir = joinpath($self->root, "build", $candidates[0]); # take the newest one
    my $dist_tarball_path = joinpath($self->root, "dists", $dist_tarball);
    my $dist_tarball_path = joinpath($self->root, "dists", $dist_tarball);
    my @paths = grep { index($_, $PERLBREW_HOME) < 0 && index($_, $self->root) < 0 } split /:/, $self->env($envname);
    $self->{log_file} = joinpath($self->root, "build.${installation_name}${variation}${append}.log");
    my $perlpath = $self->root . "/perls/$installation_name";
    my $patchperl = $self->root . "/bin/patchperl";
    print "Installing $dist_extracted_dir into " . $self->path_with_tilde("@{[ $self->root ]}/perls/$installation_name") . "\n\n";
        my $newperl = joinpath($self->root, "perls", $installation_name, "bin", "perl");
          joinpath( $self->root, 'perls', $installation_name, '.version' );
    my $out = $self->root . "/bin/" . $program_name;
    mkpath("@{[ $self->root ]}/bin") unless -d "@{[ $self->root ]}/bin";
    my $root = $self->root;
        PERLBREW_PATH    => joinpath($self->root, "bin"),
        PERLBREW_ROOT => $self->root
        if(-d  "@{[ $self->root ]}/perls/$perl_name/bin") {
            $env{PERLBREW_PATH}   .= ":" . joinpath($self->root, "perls", $perl_name, "bin");
            $env{PERLBREW_MANPATH} = joinpath($self->root, "perls", $perl_name, "man")
            my $root_dir = $self->root;
        my $root = $self->root;
    die "${dist} is not installed\n" unless -d joinpath($self->root, "perls", $dist);
    my $root = $self->root;
    my $dir = "@{[ $self->root ]}/perls/$target";
        next if -l $self->root . '/perls/' . $i->{name}; # Skip Aliases
    my $root = $self->root;
    my $path_name  = joinpath($self->root, "perls", $name);
    my $path_alias = joinpath($self->root, "perls", $alias) if $alias;
    joinpath( $self->root, 'Config.pm' );