get_maintainer.pl

#!/usr/bin/env perl
# (c) 2007, Joe Perches <joe@perches.com>
#           created from checkpatch.pl
#
# Print selected MAINTAINERS information for
# the files modified in a patch or for a file
#
# usage: perl scripts/get_maintainer.pl [OPTIONS] <patch>
#        perl scripts/get_maintainer.pl [OPTIONS] -f <file>
#
# Licensed under the terms of the GNU GPL License version 2

use warnings;
use strict;

my $P = $0;
my $V = '0.26';

use Getopt::Long qw(:config no_auto_abbrev);
use Cwd;
use File::Find;

my $cur_path = fastgetcwd() . '/';
my $lk_path = "./";
my $email = 1;
my $email_usename = 1;
my $email_maintainer = 1;
my $email_reviewer = 1;
my $email_list = 1;
my $email_subscriber_list = 0;
my $email_git_penguin_chiefs = 0;
my $email_git = 0;
my $email_git_all_signature_types = 0;
my $email_git_blame = 0;
my $email_git_blame_signatures = 1;
my $email_git_fallback = 1;
my $email_git_min_signatures = 1;
my $email_git_max_maintainers = 5;
my $email_git_min_percent = 5;
my $email_git_since = "1-year-ago";
my $email_hg_since = "-365";
my $interactive = 0;
my $email_remove_duplicates = 1;
my $email_use_mailmap = 1;
my $output_multiline = 1;
my $output_separator = ", ";
my $output_roles = 0;
my $output_rolestats = 1;
my $output_section_maxlen = 50;
my $scm = 0;
my $web = 0;
my $subsystem = 0;
my $status = 0;
my $letters = "";
my $keywords = 1;
my $sections = 0;
my $file_emails = 0;
my $from_filename = 0;
my $pattern_depth = 0;
my $self_test = 0;
my $version = 0;
my $help = 0;
my $find_maintainer_files = 0;

my $vcs_used = 0;

my $exit = 0;

my %commit_author_hash;
my %commit_signer_hash;

my @penguin_chief = ();
push(@penguin_chief, "Linus Torvalds:torvalds\@linux-foundation.org");
#Andrew wants in on most everything - 2009/01/14
#push(@penguin_chief, "Andrew Morton:akpm\@linux-foundation.org");

my @penguin_chief_names = ();
foreach my $chief (@penguin_chief) {
    if ($chief =~ m/^(.*):(.*)/) {
	my $chief_name = $1;
	my $chief_addr = $2;
	push(@penguin_chief_names, $chief_name);
    }
}
my $penguin_chiefs = "\(" . join("|", @penguin_chief_names) . "\)";

# Signature types of people who are either
# 	a) responsible for the code in question, or
# 	b) familiar enough with it to give relevant feedback
my @signature_tags = ();
push(@signature_tags, "Signed-off-by:");
push(@signature_tags, "Reviewed-by:");
push(@signature_tags, "Acked-by:");

my $signature_pattern = "\(" . join("|", @signature_tags) . "\)";

# rfc822 email address - preloaded methods go here.
my $rfc822_lwsp = "(?:(?:\\r\\n)?[ \\t])";
my $rfc822_char = '[\\000-\\377]';

# VCS command support: class-like functions and strings

my %VCS_cmds;

my %VCS_cmds_git = (
    "execute_cmd" => \&git_execute_cmd,
    "available" => '(which("git") ne "") && (-e ".git")',
    "find_signers_cmd" =>
	"git log --no-color --follow --since=\$email_git_since " .
	    '--numstat --no-merges ' .
	    '--format="GitCommit: %H%n' .
		      'GitAuthor: %an <%ae>%n' .
		      'GitDate: %aD%n' .
		      'GitSubject: %s%n' .
		      '%b%n"' .
	    " -- \$file",
    "find_commit_signers_cmd" =>
	"git log --no-color " .
	    '--numstat ' .
	    '--format="GitCommit: %H%n' .
		      'GitAuthor: %an <%ae>%n' .
		      'GitDate: %aD%n' .
		      'GitSubject: %s%n' .
		      '%b%n"' .
	    " -1 \$commit",
    "find_commit_author_cmd" =>
	"git log --no-color " .
	    '--numstat ' .
	    '--format="GitCommit: %H%n' .
		      'GitAuthor: %an <%ae>%n' .
		      'GitDate: %aD%n' .
		      'GitSubject: %s%n"' .
	    " -1 \$commit",
    "blame_range_cmd" => "git blame -l -L \$diff_start,+\$diff_length \$file",
    "blame_file_cmd" => "git blame -l \$file",
    "commit_pattern" => "^GitCommit: ([0-9a-f]{40,40})",
    "blame_commit_pattern" => "^([0-9a-f]+) ",
    "author_pattern" => "^GitAuthor: (.*)",
    "subject_pattern" => "^GitSubject: (.*)",
    "stat_pattern" => "^(\\d+)\\t(\\d+)\\t\$file\$",
    "file_exists_cmd" => "git ls-files \$file",
    "list_files_cmd" => "git ls-files \$file",
);

my %VCS_cmds_hg = (
    "execute_cmd" => \&hg_execute_cmd,
    "available" => '(which("hg") ne "") && (-d ".hg")',
    "find_signers_cmd" =>
	"hg log --date=\$email_hg_since " .
	    "--template='HgCommit: {node}\\n" .
	                "HgAuthor: {author}\\n" .
			"HgSubject: {desc}\\n'" .
	    " -- \$file",
    "find_commit_signers_cmd" =>
	"hg log " .
	    "--template='HgSubject: {desc}\\n'" .
	    " -r \$commit",
    "find_commit_author_cmd" =>
	"hg log " .
	    "--template='HgCommit: {node}\\n" .
		        "HgAuthor: {author}\\n" .
			"HgSubject: {desc|firstline}\\n'" .
	    " -r \$commit",
    "blame_range_cmd" => "",		# not supported
    "blame_file_cmd" => "hg blame -n \$file",
    "commit_pattern" => "^HgCommit: ([0-9a-f]{40,40})",
    "blame_commit_pattern" => "^([ 0-9a-f]+):",
    "author_pattern" => "^HgAuthor: (.*)",
    "subject_pattern" => "^HgSubject: (.*)",
    "stat_pattern" => "^(\\d+)\t(\\d+)\t\$file\$",
    "file_exists_cmd" => "hg files \$file",
    "list_files_cmd" => "hg manifest -R \$file",
);

my $conf = which_conf(".get_maintainer.conf");
if (-f $conf) {
    my @conf_args;
    open(my $conffile, '<', "$conf")
	or warn "$P: Can't find a readable .get_maintainer.conf file $!\n";

    while (<$conffile>) {
	my $line = $_;

	$line =~ s/\s*\n?$//g;
	$line =~ s/^\s*//g;
	$line =~ s/\s+/ /g;

	next if ($line =~ m/^\s*#/);
	next if ($line =~ m/^\s*$/);

	my @words = split(" ", $line);
	foreach my $word (@words) {
	    last if ($word =~ m/^#/);
	    push (@conf_args, $word);
	}
    }
    close($conffile);
    unshift(@ARGV, @conf_args) if @conf_args;
}

my @ignore_emails = ();
my $ignore_file = which_conf(".get_maintainer.ignore");
if (-f $ignore_file) {
    open(my $ignore, '<', "$ignore_file")
	or warn "$P: Can't find a readable .get_maintainer.ignore file $!\n";
    while (<$ignore>) {
	my $line = $_;

	$line =~ s/\s*\n?$//;
	$line =~ s/^\s*//;
	$line =~ s/\s+$//;
	$line =~ s/#.*$//;

	next if ($line =~ m/^\s*$/);
	if (rfc822_valid($line)) {
	    push(@ignore_emails, $line);
	}
    }
    close($ignore);
}

if ($#ARGV > 0) {
    foreach (@ARGV) {
        if ($_ eq "-self-test" || $_ eq "--self-test") {
            die "$P: using --self-test does not allow any other option or argument\n";
        }
    }
}

if (!GetOptions(
		'email!' => \$email,
		'git!' => \$email_git,
		'git-all-signature-types!' => \$email_git_all_signature_types,
		'git-blame!' => \$email_git_blame,
		'git-blame-signatures!' => \$email_git_blame_signatures,
		'git-fallback!' => \$email_git_fallback,
		'git-chief-penguins!' => \$email_git_penguin_chiefs,
		'git-min-signatures=i' => \$email_git_min_signatures,
		'git-max-maintainers=i' => \$email_git_max_maintainers,
		'git-min-percent=i' => \$email_git_min_percent,
		'git-since=s' => \$email_git_since,
		'hg-since=s' => \$email_hg_since,
		'i|interactive!' => \$interactive,
		'remove-duplicates!' => \$email_remove_duplicates,
		'mailmap!' => \$email_use_mailmap,
		'm!' => \$email_maintainer,
		'r!' => \$email_reviewer,
		'n!' => \$email_usename,
		'l!' => \$email_list,
		's!' => \$email_subscriber_list,
		'multiline!' => \$output_multiline,
		'roles!' => \$output_roles,
		'rolestats!' => \$output_rolestats,
		'separator=s' => \$output_separator,
		'subsystem!' => \$subsystem,
		'status!' => \$status,
		'scm!' => \$scm,
		'web!' => \$web,
		'letters=s' => \$letters,
		'pattern-depth=i' => \$pattern_depth,
		'k|keywords!' => \$keywords,
		'sections!' => \$sections,
		'fe|file-emails!' => \$file_emails,
		'f|file' => \$from_filename,
		'find-maintainer-files' => \$find_maintainer_files,
		'self-test' => \$self_test,
		'v|version' => \$version,
		'h|help|usage' => \$help,
		)) {
    die "$P: invalid argument - use --help if necessary\n";
}

if ($help != 0) {
    usage();
    exit 0;
}

if ($version != 0) {
    print("${P} ${V}\n");
    exit 0;
}

if ($self_test) {
    read_all_maintainer_files();
    check_maintainers_patterns();
    exit 0;
}

if (-t STDIN && !@ARGV) {
    # We're talking to a terminal, but have no command line arguments.
    die "$P: missing patchfile or -f file - use --help if necessary\n";
}

$output_multiline = 0 if ($output_separator ne ", ");
$output_rolestats = 1 if ($interactive);
$output_roles = 1 if ($output_rolestats);

if ($sections || $letters ne "") {
    $sections = 1;
    $email = 0;
    $email_list = 0;
    $scm = 0;
    $status = 0;
    $subsystem = 0;
    $web = 0;
    $keywords = 0;
    $interactive = 0;
} else {
    my $selections = $email + $scm + $status + $subsystem + $web;
    if ($selections == 0) {
	die "$P:  Missing required option: email, scm, status, subsystem or web\n";
    }
}

if ($email &&
    ($email_maintainer + $email_reviewer +
     $email_list + $email_subscriber_list +
     $email_git + $email_git_penguin_chiefs + $email_git_blame) == 0) {
    die "$P: Please select at least 1 email option\n";
}

if (!top_of_kernel_tree($lk_path)) {
    die "$P: The current directory does not appear to be "
	. "a linux kernel source tree.\n";
}

## Read MAINTAINERS for type/value pairs

my @typevalue = ();
my %keyword_hash;
my @mfiles = ();
my @self_test_pattern_info = ();

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

    open (my $maint, '<', "$file")
	or die "$P: Can't open MAINTAINERS file '$file': $!\n";
    my $i = 1;
    while (<$maint>) {
	my $line = $_;

	if ($line =~ m/^([A-Z]):\s*(.*)/) {
	    my $type = $1;
	    my $value = $2;

	    ##Filename pattern matching
	    if ($type eq "F" || $type eq "X") {
		$value =~ s@\.@\\\.@g;       ##Convert . to \.
		$value =~ s/\*/\.\*/g;       ##Convert * to .*
		$value =~ s/\?/\./g;         ##Convert ? to .
		##if pattern is a directory and it lacks a trailing slash, add one
		if ((-d $value)) {
		    $value =~ s@([^/])$@$1/@;
		}
		if ($self_test) {
			push(@self_test_pattern_info, {file=>$file, line=>$line, linenr=>$i, pat=>$value});
		}
	    } elsif ($type eq "K") {
		$keyword_hash{@typevalue} = $value;
	    }
	    push(@typevalue, "$type:$value");
	} elsif (!(/^\s*$/ || /^\s*\#/)) {
	    $line =~ s/\n$//g;
	    push(@typevalue, $line);
	}
	$i++;
    }
    close($maint);
}

sub find_is_maintainer_file {
    my ($file) = $_;
    return if ($file !~ m@/MAINTAINERS$@);
    $file = $File::Find::name;
    return if (! -f $file);
    push(@mfiles, $file);
}

sub find_ignore_git {
    return grep { $_ !~ /^\.git$/; } @_;
}

read_all_maintainer_files();

sub read_all_maintainer_files {
    if (-d "${lk_path}MAINTAINERS") {
        opendir(DIR, "${lk_path}MAINTAINERS") or die $!;
        my @files = readdir(DIR);
        closedir(DIR);
        foreach my $file (@files) {
            push(@mfiles, "${lk_path}MAINTAINERS/$file") if ($file !~ /^\./);
        }
    }

    if ($find_maintainer_files) {
        find( { wanted => \&find_is_maintainer_file,
                preprocess => \&find_ignore_git,
                no_chdir => 1,
        }, "${lk_path}");
    } else {
        push(@mfiles, "${lk_path}MAINTAINERS") if -f "${lk_path}MAINTAINERS";
    }

    foreach my $file (@mfiles) {
        read_maintainer_file("$file");
    }
}

#
# Read mail address map
#

my $mailmap;

read_mailmap();

sub read_mailmap {
    $mailmap = {
	names => {},
	addresses => {}
    };

    return if (!$email_use_mailmap || !(-f "${lk_path}.mailmap"));

    open(my $mailmap_file, '<', "${lk_path}.mailmap")
	or warn "$P: Can't open .mailmap: $!\n";

    while (<$mailmap_file>) {
	s/#.*$//; #strip comments
	s/^\s+|\s+$//g; #trim

	next if (/^\s*$/); #skip empty lines
	#entries have one of the following formats:
	# name1 <mail1>
	# <mail1> <mail2>
	# name1 <mail1> <mail2>
	# name1 <mail1> name2 <mail2>
	# (see man git-shortlog)

	if (/^([^<]+)<([^>]+)>$/) {
	    my $real_name = $1;
	    my $address = $2;

	    $real_name =~ s/\s+$//;
	    ($real_name, $address) = parse_email("$real_name <$address>");
	    $mailmap->{names}->{$address} = $real_name;

	} elsif (/^<([^>]+)>\s*<([^>]+)>$/) {
	    my $real_address = $1;
	    my $wrong_address = $2;

	    $mailmap->{addresses}->{$wrong_address} = $real_address;

	} elsif (/^(.+)<([^>]+)>\s*<([^>]+)>$/) {
	    my $real_name = $1;
	    my $real_address = $2;
	    my $wrong_address = $3;

	    $real_name =~ s/\s+$//;
	    ($real_name, $real_address) =
		parse_email("$real_name <$real_address>");
	    $mailmap->{names}->{$wrong_address} = $real_name;
	    $mailmap->{addresses}->{$wrong_address} = $real_address;

	} elsif (/^(.+)<([^>]+)>\s*(.+)\s*<([^>]+)>$/) {
	    my $real_name = $1;
	    my $real_address = $2;
	    my $wrong_name = $3;
	    my $wrong_address = $4;

	    $real_name =~ s/\s+$//;
	    ($real_name, $real_address) =
		parse_email("$real_name <$real_address>");

	    $wrong_name =~ s/\s+$//;
	    ($wrong_name, $wrong_address) =
		parse_email("$wrong_name <$wrong_address>");

	    my $wrong_email = format_email($wrong_name, $wrong_address, 1);
	    $mailmap->{names}->{$wrong_email} = $real_name;
	    $mailmap->{addresses}->{$wrong_email} = $real_address;
	}
    }
    close($mailmap_file);
}

## use the filenames on the command line or find the filenames in the patchfiles

my @files = ();
my @range = ();
my @keyword_tvi = ();
my @file_emails = ();

if (!@ARGV) {
    push(@ARGV, "&STDIN");
}

foreach my $file (@ARGV) {
    if ($file ne "&STDIN") {
	##if $file is a directory and it lacks a trailing slash, add one
	if ((-d $file)) {
	    $file =~ s@([^/])$@$1/@;
	} elsif (!(-f $file)) {
	    die "$P: file '${file}' not found\n";
	}
    }
    if ($from_filename || ($file ne "&STDIN" && vcs_file_exists($file))) {
	$file =~ s/^\Q${cur_path}\E//;	#strip any absolute path
	$file =~ s/^\Q${lk_path}\E//;	#or the path to the lk tree
	push(@files, $file);
	if ($file ne "MAINTAINERS" && -f $file && ($keywords || $file_emails)) {
	    open(my $f, '<', $file)
		or die "$P: Can't open $file: $!\n";
	    my $text = do { local($/) ; <$f> };
	    close($f);
	    if ($keywords) {
		foreach my $line (keys %keyword_hash) {
		    if ($text =~ m/$keyword_hash{$line}/x) {
			push(@keyword_tvi, $line);
		    }
		}
	    }
	    if ($file_emails) {
		my @poss_addr = $text =~ m$[A-Za-zÀ-ÿ\"\' \,\.\+-]*\s*[\,]*\s*[\(\<\{]{0,1}[A-Za-z0-9_\.\+-]+\@[A-Za-z0-9\.-]+\.[A-Za-z0-9]+[\)\>\}]{0,1}$g;
		push(@file_emails, clean_file_emails(@poss_addr));
	    }
	}
    } else {
	my $file_cnt = @files;
	my $lastfile;

	open(my $patch, "< $file")
	    or die "$P: Can't open $file: $!\n";

	# We can check arbitrary information before the patch
	# like the commit message, mail headers, etc...
	# This allows us to match arbitrary keywords against any part
	# of a git format-patch generated file (subject tags, etc...)

	my $patch_prefix = "";			#Parsing the intro

	while (<$patch>) {
	    my $patch_line = $_;
	    if (m/^\+\+\+\s+(\S+)/ or m/^---\s+(\S+)/) {
		my $filename = $1;
		$filename =~ s@^[^/]*/@@;
		$filename =~ s@\n@@;
		$lastfile = $filename;
		push(@files, $filename);
		$patch_prefix = "^[+-].*";	#Now parsing the actual patch
	    } elsif (m/^\@\@ -(\d+),(\d+)/) {
		if ($email_git_blame) {
		    push(@range, "$lastfile:$1:$2");
		}
	    } elsif ($keywords) {
		foreach my $line (keys %keyword_hash) {
		    if ($patch_line =~ m/${patch_prefix}$keyword_hash{$line}/x) {
			push(@keyword_tvi, $line);
		    }
		}
	    }
	}
	close($patch);

	if ($file_cnt == @files) {
	    warn "$P: file '${file}' doesn't appear to be a patch.  "
		. "Add -f to options?\n";
	}
	@files = sort_and_uniq(@files);
    }
}

@file_emails = uniq(@file_emails);

my %email_hash_name;
my %email_hash_address;
my @email_to = ();
my %hash_list_to;
my @list_to = ();
my @scm = ();
my @web = ();
my @subsystem = ();
my @status = ();
my %deduplicate_name_hash = ();
my %deduplicate_address_hash = ();

my @maintainers = get_maintainers();

if (@maintainers) {
    @maintainers = merge_email(@maintainers);
    output(@maintainers);
}

if ($scm) {
    @scm = uniq(@scm);
    output(@scm);
}

if ($status) {
    @status = uniq(@status);
    output(@status);
}

if ($subsystem) {
    @subsystem = uniq(@subsystem);
    output(@subsystem);
}

if ($web) {
    @web = uniq(@web);
    output(@web);
}

exit($exit);

sub check_maintainers_patterns {
    my @lsfiles = ();

    @lsfiles = vcs_list_files($lk_path);

    for my $x (@self_test_pattern_info) {
        if (!grep(m@^$x->{pat}@, @lsfiles)) {
            my $line = $x->{line};
            chomp($line);
            print("$x->{file}:$x->{linenr}: warning: no matches $line\n");
        }
    }
}

sub ignore_email_address {
    my ($address) = @_;

    foreach my $ignore (@ignore_emails) {
	return 1 if ($ignore eq $address);
    }

    return 0;
}

sub range_is_maintained {
    my ($start, $end) = @_;

    for (my $i = $start; $i < $end; $i++) {
	my $line = $typevalue[$i];
	if ($line =~ m/^([A-Z]):\s*(.*)/) {
	    my $type = $1;
	    my $value = $2;
	    if ($type eq 'S') {
		if ($value =~ /(maintain|support)/i) {
		    return 1;
		}
	    }
	}
    }
    return 0;
}

sub range_has_maintainer {
    my ($start, $end) = @_;

    for (my $i = $start; $i < $end; $i++) {
	my $line = $typevalue[$i];
	if ($line =~ m/^([A-Z]):\s*(.*)/) {
	    my $type = $1;
	    my $value = $2;
	    if ($type eq 'M') {
		return 1;
	    }
	}
    }
    return 0;
}

sub get_maintainers {
    %email_hash_name = ();
    %email_hash_address = ();
    %commit_author_hash = ();
    %commit_signer_hash = ();
    @email_to = ();
    %hash_list_to = ();
    @list_to = ();
    @scm = ();
    @web = ();
    @subsystem = ();
    @status = ();
    %deduplicate_name_hash = ();
    %deduplicate_address_hash = ();
    if ($email_git_all_signature_types) {
	$signature_pattern = "(.+?)[Bb][Yy]:";
    } else {
	$signature_pattern = "\(" . join("|", @signature_tags) . "\)";
    }

    # Find responsible parties

    my %exact_pattern_match_hash = ();

    foreach my $file (@files) {

	my %hash;
	my $tvi = find_first_section();
	while ($tvi < @typevalue) {
	    my $start = find_starting_index($tvi);
	    my $end = find_ending_index($tvi);
	    my $exclude = 0;
	    my $i;

	    #Do not match excluded file patterns

	    for ($i = $start; $i < $end; $i++) {
		my $line = $typevalue[$i];
		if ($line =~ m/^([A-Z]):\s*(.*)/) {
		    my $type = $1;
		    my $value = $2;
		    if ($type eq 'X') {
			if (file_match_pattern($file, $value)) {
			    $exclude = 1;
			    last;
			}
		    }
		}
	    }

	    if (!$exclude) {
		for ($i = $start; $i < $end; $i++) {
		    my $line = $typevalue[$i];
		    if ($line =~ m/^([A-Z]):\s*(.*)/) {
			my $type = $1;
			my $value = $2;
			if ($type eq 'F') {
			    if (file_match_pattern($file, $value)) {
				my $value_pd = ($value =~ tr@/@@);
				my $file_pd = ($file  =~ tr@/@@);
				$value_pd++ if (substr($value,-1,1) ne "/");
				$value_pd = -1 if ($value =~ /^\.\*/);
				if ($value_pd >= $file_pd &&
				    range_is_maintained($start, $end) &&
				    range_has_maintainer($start, $end)) {
				    $exact_pattern_match_hash{$file} = 1;
				}
				if ($pattern_depth == 0 ||
				    (($file_pd - $value_pd) < $pattern_depth)) {
				    $hash{$tvi} = $value_pd;
				}
			    }
			} elsif ($type eq 'N') {
			    if ($file =~ m/$value/x) {
				$hash{$tvi} = 0;
			    }
			}
		    }
		}
	    }
	    $tvi = $end + 1;
	}

	foreach my $line (sort {$hash{$b} <=> $hash{$a}} keys %hash) {
	    add_categories($line);
	    if ($sections) {
		my $i;
		my $start = find_starting_index($line);
		my $end = find_ending_index($line);
		for ($i = $start; $i < $end; $i++) {
		    my $line = $typevalue[$i];
		    if ($line =~ /^[FX]:/) {		##Restore file patterns
			$line =~ s/([^\\])\.([^\*])/$1\?$2/g;
			$line =~ s/([^\\])\.$/$1\?/g;	##Convert . back to ?
			$line =~ s/\\\./\./g;       	##Convert \. to .
			$line =~ s/\.\*/\*/g;       	##Convert .* to *
		    }
		    my $count = $line =~ s/^([A-Z]):/$1:\t/g;
		    if ($letters eq "" || (!$count || $letters =~ /$1/i)) {
			print("$line\n");
		    }
		}
		print("\n");
	    }
	}
    }

    if ($keywords) {
	@keyword_tvi = sort_and_uniq(@keyword_tvi);
	foreach my $line (@keyword_tvi) {
	    add_categories($line);
	}
    }

    foreach my $email (@email_to, @list_to) {
	$email->[0] = deduplicate_email($email->[0]);
    }

    foreach my $file (@files) {
	if ($email &&
	    ($email_git || ($email_git_fallback &&
			    !$exact_pattern_match_hash{$file}))) {
	    vcs_file_signoffs($file);
	}
	if ($email && $email_git_blame) {
	    vcs_file_blame($file);
	}
    }

    if ($email) {
	foreach my $chief (@penguin_chief) {
	    if ($chief =~ m/^(.*):(.*)/) {
		my $email_address;

		$email_address = format_email($1, $2, $email_usename);
		if ($email_git_penguin_chiefs) {
		    push(@email_to, [$email_address, 'chief penguin']);
		} else {
		    @email_to = grep($_->[0] !~ /${email_address}/, @email_to);
		}
	    }
	}

	foreach my $email (@file_emails) {
	    my ($name, $address) = parse_email($email);

	    my $tmp_email = format_email($name, $address, $email_usename);
	    push_email_address($tmp_email, '');
	    add_role($tmp_email, 'in file');
	}
    }

    my @to = ();
    if ($email || $email_list) {
	if ($email) {
	    @to = (@to, @email_to);
	}
	if ($email_list) {
	    @to = (@to, @list_to);
	}
    }

    if ($interactive) {
	@to = interactive_get_maintainers(\@to);
    }

    return @to;
}

sub file_match_pattern {
    my ($file, $pattern) = @_;
    if (substr($pattern, -1) eq "/") {
	if ($file =~ m@^$pattern@) {
	    return 1;
	}
    } else {
	if ($file =~ m@^$pattern@) {
	    my $s1 = ($file =~ tr@/@@);
	    my $s2 = ($pattern =~ tr@/@@);
	    if ($s1 == $s2) {
		return 1;
	    }
	}
    }
    return 0;
}

sub usage {
    print <<EOT;
usage: $P [options] patchfile
       $P [options] -f file|directory
version: $V

MAINTAINER field selection options:
  --email => print email address(es) if any
    --git => include recent git \*-by: signers
    --git-all-signature-types => include signers regardless of signature type
        or use only ${signature_pattern} signers (default: $email_git_all_signature_types)
    --git-fallback => use git when no exact MAINTAINERS pattern (default: $email_git_fallback)
    --git-chief-penguins => include ${penguin_chiefs}
    --git-min-signatures => number of signatures required (default: $email_git_min_signatures)
    --git-max-maintainers => maximum maintainers to add (default: $email_git_max_maintainers)
    --git-min-percent => minimum percentage of commits required (default: $email_git_min_percent)
    --git-blame => use git blame to find modified commits for patch or file
    --git-blame-signatures => when used with --git-blame, also include all commit signers
    --git-since => git history to use (default: $email_git_since)
    --hg-since => hg history to use (default: $email_hg_since)
    --interactive => display a menu (mostly useful if used with the --git option)
    --m => include maintainer(s) if any
    --r => include reviewer(s) if any
    --n => include name 'Full Name <addr\@domain.tld>'
    --l => include list(s) if any
    --s => include subscriber only list(s) if any
    --remove-duplicates => minimize duplicate email names/addresses
    --roles => show roles (status:subsystem, git-signer, list, etc...)
    --rolestats => show roles and statistics (commits/total_commits, %)
    --file-emails => add email addresses found in -f file (default: 0 (off))
  --scm => print SCM tree(s) if any
  --status => print status if any
  --subsystem => print subsystem name if any
  --web => print website(s) if any

Output type options:
  --separator [, ] => separator for multiple entries on 1 line
    using --separator also sets --nomultiline if --separator is not [, ]
  --multiline => print 1 entry per line

Other options:
  --pattern-depth => Number of pattern directory traversals (default: 0 (all))
  --keywords => scan patch for keywords (default: $keywords)
  --sections => print all of the subsystem sections with pattern matches
  --letters => print all matching 'letter' types from all matching sections
  --mailmap => use .mailmap file (default: $email_use_mailmap)
  --self-test => show potential issues with MAINTAINERS file content
  --version => show version
  --help => show this help information

Default options:
  [--email --nogit --git-fallback --m --r --n --l --multiline --pattern-depth=0
   --remove-duplicates --rolestats]

Notes:
  Using "-f directory" may give unexpected results:
      Used with "--git", git signators for _all_ files in and below
          directory are examined as git recurses directories.
          Any specified X: (exclude) pattern matches are _not_ ignored.
      Used with "--nogit", directory is used as a pattern match,
          no individual file within the directory or subdirectory
          is matched.
      Used with "--git-blame", does not iterate all files in directory
  Using "--git-blame" is slow and may add old committers and authors
      that are no longer active maintainers to the output.
  Using "--roles" or "--rolestats" with git send-email --cc-cmd or any
      other automated tools that expect only ["name"] <email address>
      may not work because of additional output after <email address>.
  Using "--rolestats" and "--git-blame" shows the #/total=% commits,
      not the percentage of the entire file authored.  # of commits is
      not a good measure of amount of code authored.  1 major commit may
      contain a thousand lines, 5 trivial commits may modify a single line.
  If git is not installed, but mercurial (hg) is installed and an .hg
      repository exists, the following options apply to mercurial:
          --git,
          --git-min-signatures, --git-max-maintainers, --git-min-percent, and
          --git-blame
      Use --hg-since not --git-since to control date selection
  File ".get_maintainer.conf", if it exists in the linux kernel source root
      directory, can change whatever get_maintainer defaults are desired.
      Entries in this file can be any command line argument.
      This file is prepended to any additional command line arguments.
      Multiple lines and # comments are allowed.
  Most options have both positive and negative forms.
      The negative forms for --<foo> are --no<foo> and --no-<foo>.

EOT
}

sub top_of_kernel_tree {
    my ($lk_path) = @_;

    if ($lk_path ne "" && substr($lk_path,length($lk_path)-1,1) ne "/") {
	$lk_path .= "/";
    }
    if (   (-f "${lk_path}COPYING")
	&& (-f "${lk_path}CREDITS")
	&& (-f "${lk_path}Kbuild")
	&& (-e "${lk_path}MAINTAINERS")
	&& (-f "${lk_path}Makefile")
	&& (-f "${lk_path}README")
	&& (-d "${lk_path}Documentation")
	&& (-d "${lk_path}arch")
	&& (-d "${lk_path}include")
	&& (-d "${lk_path}drivers")
	&& (-d "${lk_path}fs")
	&& (-d "${lk_path}init")
	&& (-d "${lk_path}ipc")
	&& (-d "${lk_path}kernel")
	&& (-d "${lk_path}lib")
	&& (-d "${lk_path}scripts")) {
	return 1;
    }
    return 0;
}

sub parse_email {
    my ($formatted_email) = @_;

    my $name = "";
    my $address = "";

    if ($formatted_email =~ /^([^<]+)<(.+\@.*)>.*$/) {
	$name = $1;
	$address = $2;
    } elsif ($formatted_email =~ /^\s*<(.+\@\S*)>.*$/) {
	$address = $1;
    } elsif ($formatted_email =~ /^(.+\@\S*).*$/) {
	$address = $1;
    }

    $name =~ s/^\s+|\s+$//g;
    $name =~ s/^\"|\"$//g;
    $address =~ s/^\s+|\s+$//g;

    if ($name =~ /[^\w \-]/i) {  	 ##has "must quote" chars
	$name =~ s/(?<!\\)"/\\"/g;       ##escape quotes
	$name = "\"$name\"";
    }

    return ($name, $address);
}

sub format_email {
    my ($name, $address, $usename) = @_;

    my $formatted_email;

    $name =~ s/^\s+|\s+$//g;
    $name =~ s/^\"|\"$//g;
    $address =~ s/^\s+|\s+$//g;

    if ($name =~ /[^\w \-]/i) {          ##has "must quote" chars
	$name =~ s/(?<!\\)"/\\"/g;       ##escape quotes
	$name = "\"$name\"";
    }

    if ($usename) {
	if ("$name" eq "") {
	    $formatted_email = "$address";
	} else {
	    $formatted_email = "$name <$address>";
	}
    } else {
	$formatted_email = $address;
    }

    return $formatted_email;
}

sub find_first_section {
    my $index = 0;

    while ($index < @typevalue) {
	my $tv = $typevalue[$index];
	if (($tv =~ m/^([A-Z]):\s*(.*)/)) {
	    last;
	}
	$index++;
    }

    return $index;
}

sub find_starting_index {
    my ($index) = @_;

    while ($index > 0) {
	my $tv = $typevalue[$index];
	if (!($tv =~ m/^([A-Z]):\s*(.*)/)) {
	    last;
	}
	$index--;
    }

    return $index;
}

sub find_ending_index {
    my ($index) = @_;

    while ($index < @typevalue) {
	my $tv = $typevalue[$index];
	if (!($tv =~ m/^([A-Z]):\s*(.*)/)) {
	    last;
	}
	$index++;
    }

    return $index;
}

sub get_subsystem_name {
    my ($index) = @_;

    my $start = find_starting_index($index);

    my $subsystem = $typevalue[$start];
    if ($output_section_maxlen && length($subsystem) > $output_section_maxlen) {
	$subsystem = substr($subsystem, 0, $output_section_maxlen - 3);
	$subsystem =~ s/\s*$//;
	$subsystem = $subsystem . "...";
    }
    return $subsystem;
}

sub get_maintainer_role {
    my ($index) = @_;

    my $i;
    my $start = find_starting_index($index);
    my $end = find_ending_index($index);

    my $role = "unknown";
    my $subsystem = get_subsystem_name($index);

    for ($i = $start + 1; $i < $end; $i++) {
	my $tv = $typevalue[$i];
	if ($tv =~ m/^([A-Z]):\s*(.*)/) {
	    my $ptype = $1;
	    my $pvalue = $2;
	    if ($ptype eq "S") {
		$role = $pvalue;
	    }
	}
    }

    $role = lc($role);
    if      ($role eq "supported") {
	$role = "supporter";
    } elsif ($role eq "maintained") {
	$role = "maintainer";
    } elsif ($role eq "odd fixes") {
	$role = "odd fixer";
    } elsif ($role eq "orphan") {
	$role = "orphan minder";
    } elsif ($role eq "obsolete") {
	$role = "obsolete minder";
    } elsif ($role eq "buried alive in reporters") {
	$role = "chief penguin";
    }

    return $role . ":" . $subsystem;
}

sub get_list_role {
    my ($index) = @_;

    my $subsystem = get_subsystem_name($index);

    if ($subsystem eq "THE REST") {
	$subsystem = "";
    }

    return $subsystem;
}

sub add_categories {
    my ($index) = @_;

    my $i;
    my $start = find_starting_index($index);
    my $end = find_ending_index($index);

    push(@subsystem, $typevalue[$start]);

    for ($i = $start + 1; $i < $end; $i++) {
	my $tv = $typevalue[$i];
	if ($tv =~ m/^([A-Z]):\s*(.*)/) {
	    my $ptype = $1;
	    my $pvalue = $2;
	    if ($ptype eq "L") {
		my $list_address = $pvalue;
		my $list_additional = "";
		my $list_role = get_list_role($i);

		if ($list_role ne "") {
		    $list_role = ":" . $list_role;
		}
		if ($list_address =~ m/([^\s]+)\s+(.*)$/) {
		    $list_address = $1;
		    $list_additional = $2;
		}
		if ($list_additional =~ m/subscribers-only/) {
		    if ($email_subscriber_list) {
			if (!$hash_list_to{lc($list_address)}) {
			    $hash_list_to{lc($list_address)} = 1;
			    push(@list_to, [$list_address,
					    "subscriber list${list_role}"]);
			}
		    }
		} else {
		    if ($email_list) {
			if (!$hash_list_to{lc($list_address)}) {
			    $hash_list_to{lc($list_address)} = 1;
			    if ($list_additional =~ m/moderated/) {
				push(@list_to, [$list_address,
						"moderated list${list_role}"]);
			    } else {
				push(@list_to, [$list_address,
						"open list${list_role}"]);
			    }
			}
		    }
		}
	    } elsif ($ptype eq "M") {
		my ($name, $address) = parse_email($pvalue);
		if ($name eq "") {
		    if ($i > 0) {
			my $tv = $typevalue[$i - 1];
			if ($tv =~ m/^([A-Z]):\s*(.*)/) {
			    if ($1 eq "P") {
				$name = $2;
				$pvalue = format_email($name, $address, $email_usename);
			    }
			}
		    }
		}
		if ($email_maintainer) {
		    my $role = get_maintainer_role($i);
		    push_email_addresses($pvalue, $role);
		}
	    } elsif ($ptype eq "R") {
		my ($name, $address) = parse_email($pvalue);
		if ($name eq "") {
		    if ($i > 0) {
			my $tv = $typevalue[$i - 1];
			if ($tv =~ m/^([A-Z]):\s*(.*)/) {
			    if ($1 eq "P") {
				$name = $2;
				$pvalue = format_email($name, $address, $email_usename);
			    }
			}
		    }
		}
		if ($email_reviewer) {
		    my $subsystem = get_subsystem_name($i);
		    push_email_addresses($pvalue, "reviewer:$subsystem");
		}
	    } elsif ($ptype eq "T") {
		push(@scm, $pvalue);
	    } elsif ($ptype eq "W") {
		push(@web, $pvalue);
	    } elsif ($ptype eq "S") {
		push(@status, $pvalue);
	    }
	}
    }
}

sub email_inuse {
    my ($name, $address) = @_;

    return 1 if (($name eq "") && ($address eq ""));
    return 1 if (($name ne "") && exists($email_hash_name{lc($name)}));
    return 1 if (($address ne "") && exists($email_hash_address{lc($address)}));

    return 0;
}

sub push_email_address {
    my ($line, $role) = @_;

    my ($name, $address) = parse_email($line);

    if ($address eq "") {
	return 0;
    }

    if (!$email_remove_duplicates) {
	push(@email_to, [format_email($name, $address, $email_usename), $role]);
    } elsif (!email_inuse($name, $address)) {
	push(@email_to, [format_email($name, $address, $email_usename), $role]);
	$email_hash_name{lc($name)}++ if ($name ne "");
	$email_hash_address{lc($address)}++;
    }

    return 1;
}

sub push_email_addresses {
    my ($address, $role) = @_;

    my @address_list = ();

    if (rfc822_valid($address)) {
	push_email_address($address, $role);
    } elsif (@address_list = rfc822_validlist($address)) {
	my $array_count = shift(@address_list);
	while (my $entry = shift(@address_list)) {
	    push_email_address($entry, $role);
	}
    } else {
	if (!push_email_address($address, $role)) {
	    warn("Invalid MAINTAINERS address: '" . $address . "'\n");
	}
    }
}

sub add_role {
    my ($line, $role) = @_;

    my ($name, $address) = parse_email($line);
    my $email = format_email($name, $address, $email_usename);

    foreach my $entry (@email_to) {
	if ($email_remove_duplicates) {
	    my ($entry_name, $entry_address) = parse_email($entry->[0]);
	    if (($name eq $entry_name || $address eq $entry_address)
		&& ($role eq "" || !($entry->[1] =~ m/$role/))
	    ) {
		if ($entry->[1] eq "") {
		    $entry->[1] = "$role";
		} else {
		    $entry->[1] = "$entry->[1],$role";
		}
	    }
	} else {
	    if ($email eq $entry->[0]
		&& ($role eq "" || !($entry->[1] =~ m/$role/))
	    ) {
		if ($entry->[1] eq "") {
		    $entry->[1] = "$role";
		} else {
		    $entry->[1] = "$entry->[1],$role";
		}
	    }
	}
    }
}

sub which {
    my ($bin) = @_;

    foreach my $path (split(/:/, $ENV{PATH})) {
	if (-e "$path/$bin") {
	    return "$path/$bin";
	}
    }

    return "";
}

sub which_conf {
    my ($conf) = @_;

    foreach my $path (split(/:/, ".:$ENV{HOME}:.scripts")) {
	if (-e "$path/$conf") {
	    return "$path/$conf";
	}
    }

    return "";
}

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

    my ($name, $address) = parse_email($line);
    my $email = format_email($name, $address, 1);
    my $real_name = $name;
    my $real_address = $address;

    if (exists $mailmap->{names}->{$email} ||
	exists $mailmap->{addresses}->{$email}) {
	if (exists $mailmap->{names}->{$email}) {
	    $real_name = $mailmap->{names}->{$email};
	}
	if (exists $mailmap->{addresses}->{$email}) {
	    $real_address = $mailmap->{addresses}->{$email};
	}
    } else {
	if (exists $mailmap->{names}->{$address}) {
	    $real_name = $mailmap->{names}->{$address};
	}
	if (exists $mailmap->{addresses}->{$address}) {
	    $real_address = $mailmap->{addresses}->{$address};
	}
    }
    return format_email($real_name, $real_address, 1);
}

sub mailmap {
    my (@addresses) = @_;

    my @mapped_emails = ();
    foreach my $line (@addresses) {
	push(@mapped_emails, mailmap_email($line));
    }
    merge_by_realname(@mapped_emails) if ($email_use_mailmap);
    return @mapped_emails;
}

sub merge_by_realname {
    my %address_map;
    my (@emails) = @_;

    foreach my $email (@emails) {
	my ($name, $address) = parse_email($email);
	if (exists $address_map{$name}) {
	    $address = $address_map{$name};
	    $email = format_email($name, $address, 1);
	} else {
	    $address_map{$name} = $address;
	}
    }
}

sub git_execute_cmd {
    my ($cmd) = @_;
    my @lines = ();

    my $output = `$cmd`;
    $output =~ s/^\s*//gm;
    @lines = split("\n", $output);

    return @lines;
}

sub hg_execute_cmd {
    my ($cmd) = @_;
    my @lines = ();

    my $output = `$cmd`;
    @lines = split("\n", $output);

    return @lines;
}

sub extract_formatted_signatures {
    my (@signature_lines) = @_;

    my @type = @signature_lines;

    s/\s*(.*):.*/$1/ for (@type);

    # cut -f2- -d":"
    s/\s*.*:\s*(.+)\s*/$1/ for (@signature_lines);

## Reformat email addresses (with names) to avoid badly written signatures

    foreach my $signer (@signature_lines) {
	$signer = deduplicate_email($signer);
    }

    return (\@type, \@signature_lines);
}

sub vcs_find_signers {
    my ($cmd, $file) = @_;
    my $commits;
    my @lines = ();
    my @signatures = ();
    my @authors = ();
    my @stats = ();

    @lines = &{$VCS_cmds{"execute_cmd"}}($cmd);

    my $pattern = $VCS_cmds{"commit_pattern"};
    my $author_pattern = $VCS_cmds{"author_pattern"};
    my $stat_pattern = $VCS_cmds{"stat_pattern"};

    $stat_pattern =~ s/(\$\w+)/$1/eeg;		#interpolate $stat_pattern

    $commits = grep(/$pattern/, @lines);	# of commits

    @authors = grep(/$author_pattern/, @lines);
    @signatures = grep(/^[ \t]*${signature_pattern}.*\@.*$/, @lines);
    @stats = grep(/$stat_pattern/, @lines);

#    print("stats: <@stats>\n");

    return (0, \@signatures, \@authors, \@stats) if !@signatures;

    save_commits_by_author(@lines) if ($interactive);
    save_commits_by_signer(@lines) if ($interactive);

    if (!$email_git_penguin_chiefs) {
	@signatures = grep(!/${penguin_chiefs}/i, @signatures);
    }

    my ($author_ref, $authors_ref) = extract_formatted_signatures(@authors);
    my ($types_ref, $signers_ref) = extract_formatted_signatures(@signatures);

    return ($commits, $signers_ref, $authors_ref, \@stats);
}

sub vcs_find_author {
    my ($cmd) = @_;
    my @lines = ();

    @lines = &{$VCS_cmds{"execute_cmd"}}($cmd);

    if (!$email_git_penguin_chiefs) {
	@lines = grep(!/${penguin_chiefs}/i, @lines);
    }

    return @lines if !@lines;

    my @authors = ();
    foreach my $line (@lines) {
	if ($line =~ m/$VCS_cmds{"author_pattern"}/) {
	    my $author = $1;
	    my ($name, $address) = parse_email($author);
	    $author = format_email($name, $address, 1);
	    push(@authors, $author);
	}
    }

    save_commits_by_author(@lines) if ($interactive);
    save_commits_by_signer(@lines) if ($interactive);

    return @authors;
}

sub vcs_save_commits {
    my ($cmd) = @_;
    my @lines = ();
    my @commits = ();

    @lines = &{$VCS_cmds{"execute_cmd"}}($cmd);

    foreach my $line (@lines) {
	if ($line =~ m/$VCS_cmds{"blame_commit_pattern"}/) {
	    push(@commits, $1);
	}
    }

    return @commits;
}

sub vcs_blame {
    my ($file) = @_;
    my $cmd;
    my @commits = ();

    return @commits if (!(-f $file));

    if (@range && $VCS_cmds{"blame_range_cmd"} eq "") {
	my @all_commits = ();

	$cmd = $VCS_cmds{"blame_file_cmd"};
	$cmd =~ s/(\$\w+)/$1/eeg;		#interpolate $cmd
	@all_commits = vcs_save_commits($cmd);

	foreach my $file_range_diff (@range) {
	    next if (!($file_range_diff =~ m/(.+):(.+):(.+)/));
	    my $diff_file = $1;
	    my $diff_start = $2;
	    my $diff_length = $3;
	    next if ("$file" ne "$diff_file");
	    for (my $i = $diff_start; $i < $diff_start + $diff_length; $i++) {
		push(@commits, $all_commits[$i]);
	    }
	}
    } elsif (@range) {
	foreach my $file_range_diff (@range) {
	    next if (!($file_range_diff =~ m/(.+):(.+):(.+)/));
	    my $diff_file = $1;
	    my $diff_start = $2;
	    my $diff_length = $3;
	    next if ("$file" ne "$diff_file");
	    $cmd = $VCS_cmds{"blame_range_cmd"};
	    $cmd =~ s/(\$\w+)/$1/eeg;		#interpolate $cmd
	    push(@commits, vcs_save_commits($cmd));
	}
    } else {
	$cmd = $VCS_cmds{"blame_file_cmd"};
	$cmd =~ s/(\$\w+)/$1/eeg;		#interpolate $cmd
	@commits = vcs_save_commits($cmd);
    }

    foreach my $commit (@commits) {
	$commit =~ s/^\^//g;
    }

    return @commits;
}

my $printed_novcs = 0;
sub vcs_exists {
    %VCS_cmds = %VCS_cmds_git;
    return 1 if eval $VCS_cmds{"available"};
    %VCS_cmds = %VCS_cmds_hg;
    return 2 if eval $VCS_cmds{"available"};
    %VCS_cmds = ();
    if (!$printed_novcs) {
	warn("$P: No supported VCS found.  Add --nogit to options?\n");
	warn("Using a git repository produces better results.\n");
	warn("Try Linus Torvalds' latest git repository using:\n");
	warn("git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git\n");
	$printed_novcs = 1;
    }
    return 0;
}

sub vcs_is_git {
    vcs_exists();
    return $vcs_used == 1;
}

sub vcs_is_hg {
    return $vcs_used == 2;
}

sub interactive_get_maintainers {
    my ($list_ref) = @_;
    my @list = @$list_ref;

    vcs_exists();

    my %selected;
    my %authored;
    my %signed;
    my $count = 0;
    my $maintained = 0;
    foreach my $entry (@list) {
	$maintained = 1 if ($entry->[1] =~ /^(maintainer|supporter)/i);
	$selected{$count} = 1;
	$authored{$count} = 0;
	$signed{$count} = 0;
	$count++;
    }

    #menu loop
    my $done = 0;
    my $print_options = 0;
    my $redraw = 1;
    while (!$done) {
	$count = 0;
	if ($redraw) {
	    printf STDERR "\n%1s %2s %-65s",
			  "*", "#", "email/list and role:stats";
	    if ($email_git ||
		($email_git_fallback && !$maintained) ||
		$email_git_blame) {
		print STDERR "auth sign";
	    }
	    print STDERR "\n";
	    foreach my $entry (@list) {
		my $email = $entry->[0];
		my $role = $entry->[1];
		my $sel = "";
		$sel = "*" if ($selected{$count});
		my $commit_author = $commit_author_hash{$email};
		my $commit_signer = $commit_signer_hash{$email};
		my $authored = 0;
		my $signed = 0;
		$authored++ for (@{$commit_author});
		$signed++ for (@{$commit_signer});
		printf STDERR "%1s %2d %-65s", $sel, $count + 1, $email;
		printf STDERR "%4d %4d", $authored, $signed
		    if ($authored > 0 || $signed > 0);
		printf STDERR "\n     %s\n", $role;
		if ($authored{$count}) {
		    my $commit_author = $commit_author_hash{$email};
		    foreach my $ref (@{$commit_author}) {
			print STDERR "     Author: @{$ref}[1]\n";
		    }
		}
		if ($signed{$count}) {
		    my $commit_signer = $commit_signer_hash{$email};
		    foreach my $ref (@{$commit_signer}) {
			print STDERR "     @{$ref}[2]: @{$ref}[1]\n";
		    }
		}

		$count++;
	    }
	}
	my $date_ref = \$email_git_since;
	$date_ref = \$email_hg_since if (vcs_is_hg());
	if ($print_options) {
	    $print_options = 0;
	    if (vcs_exists()) {
		print STDERR <<EOT

Version Control options:
g  use git history      [$email_git]
gf use git-fallback     [$email_git_fallback]
b  use git blame        [$email_git_blame]
bs use blame signatures [$email_git_blame_signatures]
c# minimum commits      [$email_git_min_signatures]
%# min percent          [$email_git_min_percent]
d# history to use       [$$date_ref]
x# max maintainers      [$email_git_max_maintainers]
t  all signature types  [$email_git_all_signature_types]
m  use .mailmap         [$email_use_mailmap]
EOT
	    }
	    print STDERR <<EOT

Additional options:
0  toggle all
tm toggle maintainers
tg toggle git entries
tl toggle open list entries
ts toggle subscriber list entries
f  emails in file       [$file_emails]
k  keywords in file     [$keywords]
r  remove duplicates    [$email_remove_duplicates]
p# pattern match depth  [$pattern_depth]
EOT
	}
	print STDERR
"\n#(toggle), A#(author), S#(signed) *(all), ^(none), O(options), Y(approve): ";

	my $input = <STDIN>;
	chomp($input);

	$redraw = 1;
	my $rerun = 0;
	my @wish = split(/[, ]+/, $input);
	foreach my $nr (@wish) {
	    $nr = lc($nr);
	    my $sel = substr($nr, 0, 1);
	    my $str = substr($nr, 1);
	    my $val = 0;
	    $val = $1 if $str =~ /^(\d+)$/;

	    if ($sel eq "y") {
		$interactive = 0;
		$done = 1;
		$output_rolestats = 0;
		$output_roles = 0;
		last;
	    } elsif ($nr =~ /^\d+$/ && $nr > 0 && $nr <= $count) {
		$selected{$nr - 1} = !$selected{$nr - 1};
	    } elsif ($sel eq "*" || $sel eq '^') {
		my $toggle = 0;
		$toggle = 1 if ($sel eq '*');
		for (my $i = 0; $i < $count; $i++) {
		    $selected{$i} = $toggle;
		}
	    } elsif ($sel eq "0") {
		for (my $i = 0; $i < $count; $i++) {
		    $selected{$i} = !$selected{$i};
		}
	    } elsif ($sel eq "t") {
		if (lc($str) eq "m") {
		    for (my $i = 0; $i < $count; $i++) {
			$selected{$i} = !$selected{$i}
			    if ($list[$i]->[1] =~ /^(maintainer|supporter)/i);
		    }
		} elsif (lc($str) eq "g") {
		    for (my $i = 0; $i < $count; $i++) {
			$selected{$i} = !$selected{$i}
			    if ($list[$i]->[1] =~ /^(author|commit|signer)/i);
		    }
		} elsif (lc($str) eq "l") {
		    for (my $i = 0; $i < $count; $i++) {
			$selected{$i} = !$selected{$i}
			    if ($list[$i]->[1] =~ /^(open list)/i);
		    }
		} elsif (lc($str) eq "s") {
		    for (my $i = 0; $i < $count; $i++) {
			$selected{$i} = !$selected{$i}
			    if ($list[$i]->[1] =~ /^(subscriber list)/i);
		    }
		}
	    } elsif ($sel eq "a") {
		if ($val > 0 && $val <= $count) {
		    $authored{$val - 1} = !$authored{$val - 1};
		} elsif ($str eq '*' || $str eq '^') {
		    my $toggle = 0;
		    $toggle = 1 if ($str eq '*');
		    for (my $i = 0; $i < $count; $i++) {
			$authored{$i} = $toggle;
		    }
		}
	    } elsif ($sel eq "s") {
		if ($val > 0 && $val <= $count) {
		    $signed{$val - 1} = !$signed{$val - 1};
		} elsif ($str eq '*' || $str eq '^') {
		    my $toggle = 0;
		    $toggle = 1 if ($str eq '*');
		    for (my $i = 0; $i < $count; $i++) {
			$signed{$i} = $toggle;
		    }
		}
	    } elsif ($sel eq "o") {
		$print_options = 1;
		$redraw = 1;
	    } elsif ($sel eq "g") {
		if ($str eq "f") {
		    bool_invert(\$email_git_fallback);
		} else {
		    bool_invert(\$email_git);
		}
		$rerun = 1;
	    } elsif ($sel eq "b") {
		if ($str eq "s") {
		    bool_invert(\$email_git_blame_signatures);
		} else {
		    bool_invert(\$email_git_blame);
		}
		$rerun = 1;
	    } elsif ($sel eq "c") {
		if ($val > 0) {
		    $email_git_min_signatures = $val;
		    $rerun = 1;
		}
	    } elsif ($sel eq "x") {
		if ($val > 0) {
		    $email_git_max_maintainers = $val;
		    $rerun = 1;
		}
	    } elsif ($sel eq "%") {
		if ($str ne "" && $val >= 0) {
		    $email_git_min_percent = $val;
		    $rerun = 1;
		}
	    } elsif ($sel eq "d") {
		if (vcs_is_git()) {
		    $email_git_since = $str;
		} elsif (vcs_is_hg()) {
		    $email_hg_since = $str;
		}
		$rerun = 1;
	    } elsif ($sel eq "t") {
		bool_invert(\$email_git_all_signature_types);
		$rerun = 1;
	    } elsif ($sel eq "f") {
		bool_invert(\$file_emails);
		$rerun = 1;
	    } elsif ($sel eq "r") {
		bool_invert(\$email_remove_duplicates);
		$rerun = 1;
	    } elsif ($sel eq "m") {
		bool_invert(\$email_use_mailmap);
		read_mailmap();
		$rerun = 1;
	    } elsif ($sel eq "k") {
		bool_invert(\$keywords);
		$rerun = 1;
	    } elsif ($sel eq "p") {
		if ($str ne "" && $val >= 0) {
		    $pattern_depth = $val;
		    $rerun = 1;
		}
	    } elsif ($sel eq "h" || $sel eq "?") {
		print STDERR <<EOT

Interactive mode allows you to select the various maintainers, submitters,
commit signers and mailing lists that could be CC'd on a patch.

Any *'d entry is selected.

If you have git or hg installed, you can choose to summarize the commit
history of files in the patch.  Also, each line of the current file can
be matched to its commit author and that commits signers with blame.

Various knobs exist to control the length of time for active commit
tracking, the maximum number of commit authors and signers to add,
and such.

Enter selections at the prompt until you are satisfied that the selected
maintainers are appropriate.  You may enter multiple selections separated
by either commas or spaces.

EOT
	    } else {
		print STDERR "invalid option: '$nr'\n";
		$redraw = 0;
	    }
	}
	if ($rerun) {
	    print STDERR "git-blame can be very slow, please have patience..."
		if ($email_git_blame);
	    goto &get_maintainers;
	}
    }

    #drop not selected entries
    $count = 0;
    my @new_emailto = ();
    foreach my $entry (@list) {
	if ($selected{$count}) {
	    push(@new_emailto, $list[$count]);
	}
	$count++;
    }
    return @new_emailto;
}

sub bool_invert {
    my ($bool_ref) = @_;

    if ($$bool_ref) {
	$$bool_ref = 0;
    } else {
	$$bool_ref = 1;
    }
}

sub deduplicate_email {
    my ($email) = @_;

    my $matched = 0;
    my ($name, $address) = parse_email($email);
    $email = format_email($name, $address, 1);
    $email = mailmap_email($email);

    return $email if (!$email_remove_duplicates);

    ($name, $address) = parse_email($email);

    if ($name ne "" && $deduplicate_name_hash{lc($name)}) {
	$name = $deduplicate_name_hash{lc($name)}->[0];
	$address = $deduplicate_name_hash{lc($name)}->[1];
	$matched = 1;
    } elsif ($deduplicate_address_hash{lc($address)}) {
	$name = $deduplicate_address_hash{lc($address)}->[0];
	$address = $deduplicate_address_hash{lc($address)}->[1];
	$matched = 1;
    }
    if (!$matched) {
	$deduplicate_name_hash{lc($name)} = [ $name, $address ];
	$deduplicate_address_hash{lc($address)} = [ $name, $address ];
    }
    $email = format_email($name, $address, 1);
    $email = mailmap_email($email);
    return $email;
}

sub save_commits_by_author {
    my (@lines) = @_;

    my @authors = ();
    my @commits = ();
    my @subjects = ();

    foreach my $line (@lines) {
	if ($line =~ m/$VCS_cmds{"author_pattern"}/) {
	    my $author = $1;
	    $author = deduplicate_email($author);
	    push(@authors, $author);
	}
	push(@commits, $1) if ($line =~ m/$VCS_cmds{"commit_pattern"}/);
	push(@subjects, $1) if ($line =~ m/$VCS_cmds{"subject_pattern"}/);
    }

    for (my $i = 0; $i < @authors; $i++) {
	my $exists = 0;
	foreach my $ref(@{$commit_author_hash{$authors[$i]}}) {
	    if (@{$ref}[0] eq $commits[$i] &&
		@{$ref}[1] eq $subjects[$i]) {
		$exists = 1;
		last;
	    }
	}
	if (!$exists) {
	    push(@{$commit_author_hash{$authors[$i]}},
		 [ ($commits[$i], $subjects[$i]) ]);
	}
    }
}

sub save_commits_by_signer {
    my (@lines) = @_;

    my $commit = "";
    my $subject = "";

    foreach my $line (@lines) {
	$commit = $1 if ($line =~ m/$VCS_cmds{"commit_pattern"}/);
	$subject = $1 if ($line =~ m/$VCS_cmds{"subject_pattern"}/);
	if ($line =~ /^[ \t]*${signature_pattern}.*\@.*$/) {
	    my @signatures = ($line);
	    my ($types_ref, $signers_ref) = extract_formatted_signatures(@signatures);
	    my @types = @$types_ref;
	    my @signers = @$signers_ref;

	    my $type = $types[0];
	    my $signer = $signers[0];

	    $signer = deduplicate_email($signer);

	    my $exists = 0;
	    foreach my $ref(@{$commit_signer_hash{$signer}}) {
		if (@{$ref}[0] eq $commit &&
		    @{$ref}[1] eq $subject &&
		    @{$ref}[2] eq $type) {
		    $exists = 1;
		    last;
		}
	    }
	    if (!$exists) {
		push(@{$commit_signer_hash{$signer}},
		     [ ($commit, $subject, $type) ]);
	    }
	}
    }
}

sub vcs_assign {
    my ($role, $divisor, @lines) = @_;

    my %hash;
    my $count = 0;

    return if (@lines <= 0);

    if ($divisor <= 0) {
	warn("Bad divisor in " . (caller(0))[3] . ": $divisor\n");
	$divisor = 1;
    }

    @lines = mailmap(@lines);

    return if (@lines <= 0);

    @lines = sort(@lines);

    # uniq -c
    $hash{$_}++ for @lines;

    # sort -rn
    foreach my $line (sort {$hash{$b} <=> $hash{$a}} keys %hash) {
	my $sign_offs = $hash{$line};
	my $percent = $sign_offs * 100 / $divisor;

	$percent = 100 if ($percent > 100);
	next if (ignore_email_address($line));
	$count++;
	last if ($sign_offs < $email_git_min_signatures ||
		 $count > $email_git_max_maintainers ||
		 $percent < $email_git_min_percent);
	push_email_address($line, '');
	if ($output_rolestats) {
	    my $fmt_percent = sprintf("%.0f", $percent);
	    add_role($line, "$role:$sign_offs/$divisor=$fmt_percent%");
	} else {
	    add_role($line, $role);
	}
    }
}

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

    my $authors_ref;
    my $signers_ref;
    my $stats_ref;
    my @authors = ();
    my @signers = ();
    my @stats = ();
    my $commits;

    $vcs_used = vcs_exists();
    return if (!$vcs_used);

    my $cmd = $VCS_cmds{"find_signers_cmd"};
    $cmd =~ s/(\$\w+)/$1/eeg;		# interpolate $cmd

    ($commits, $signers_ref, $authors_ref, $stats_ref) = vcs_find_signers($cmd, $file);

    @signers = @{$signers_ref} if defined $signers_ref;
    @authors = @{$authors_ref} if defined $authors_ref;
    @stats = @{$stats_ref} if defined $stats_ref;

#    print("commits: <$commits>\nsigners:<@signers>\nauthors: <@authors>\nstats: <@stats>\n");

    foreach my $signer (@signers) {
	$signer = deduplicate_email($signer);
    }

    vcs_assign("commit_signer", $commits, @signers);
    vcs_assign("authored", $commits, @authors);
    if ($#authors == $#stats) {
	my $stat_pattern = $VCS_cmds{"stat_pattern"};
	$stat_pattern =~ s/(\$\w+)/$1/eeg;	#interpolate $stat_pattern

	my $added = 0;
	my $deleted = 0;
	for (my $i = 0; $i <= $#stats; $i++) {
	    if ($stats[$i] =~ /$stat_pattern/) {
		$added += $1;
		$deleted += $2;
	    }
	}
	my @tmp_authors = uniq(@authors);
	foreach my $author (@tmp_authors) {
	    $author = deduplicate_email($author);
	}
	@tmp_authors = uniq(@tmp_authors);
	my @list_added = ();
	my @list_deleted = ();
	foreach my $author (@tmp_authors) {
	    my $auth_added = 0;
	    my $auth_deleted = 0;
	    for (my $i = 0; $i <= $#stats; $i++) {
		if ($author eq deduplicate_email($authors[$i]) &&
		    $stats[$i] =~ /$stat_pattern/) {
		    $auth_added += $1;
		    $auth_deleted += $2;
		}
	    }
	    for (my $i = 0; $i < $auth_added; $i++) {
		push(@list_added, $author);
	    }
	    for (my $i = 0; $i < $auth_deleted; $i++) {
		push(@list_deleted, $author);
	    }
	}
	vcs_assign("added_lines", $added, @list_added);
	vcs_assign("removed_lines", $deleted, @list_deleted);
    }
}

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

    my @signers = ();
    my @all_commits = ();
    my @commits = ();
    my $total_commits;
    my $total_lines;

    $vcs_used = vcs_exists();
    return if (!$vcs_used);

    @all_commits = vcs_blame($file);
    @commits = uniq(@all_commits);
    $total_commits = @commits;
    $total_lines = @all_commits;

    if ($email_git_blame_signatures) {
	if (vcs_is_hg()) {
	    my $commit_count;
	    my $commit_authors_ref;
	    my $commit_signers_ref;
	    my $stats_ref;
	    my @commit_authors = ();
	    my @commit_signers = ();
	    my $commit = join(" -r ", @commits);
	    my $cmd;

	    $cmd = $VCS_cmds{"find_commit_signers_cmd"};
	    $cmd =~ s/(\$\w+)/$1/eeg;	#substitute variables in $cmd

	    ($commit_count, $commit_signers_ref, $commit_authors_ref, $stats_ref) = vcs_find_signers($cmd, $file);
	    @commit_authors = @{$commit_authors_ref} if defined $commit_authors_ref;
	    @commit_signers = @{$commit_signers_ref} if defined $commit_signers_ref;

	    push(@signers, @commit_signers);
	} else {
	    foreach my $commit (@commits) {
		my $commit_count;
		my $commit_authors_ref;
		my $commit_signers_ref;
		my $stats_ref;
		my @commit_authors = ();
		my @commit_signers = ();
		my $cmd;

		$cmd = $VCS_cmds{"find_commit_signers_cmd"};
		$cmd =~ s/(\$\w+)/$1/eeg;	#substitute variables in $cmd

		($commit_count, $commit_signers_ref, $commit_authors_ref, $stats_ref) = vcs_find_signers($cmd, $file);
		@commit_authors = @{$commit_authors_ref} if defined $commit_authors_ref;
		@commit_signers = @{$commit_signers_ref} if defined $commit_signers_ref;

		push(@signers, @commit_signers);
	    }
	}
    }

    if ($from_filename) {
	if ($output_rolestats) {
	    my @blame_signers;
	    if (vcs_is_hg()) {{		# Double brace for last exit
		my $commit_count;
		my @commit_signers = ();
		@commits = uniq(@commits);
		@commits = sort(@commits);
		my $commit = join(" -r ", @commits);
		my $cmd;

		$cmd = $VCS_cmds{"find_commit_author_cmd"};
		$cmd =~ s/(\$\w+)/$1/eeg;	#substitute variables in $cmd

		my @lines = ();

		@lines = &{$VCS_cmds{"execute_cmd"}}($cmd);

		if (!$email_git_penguin_chiefs) {
		    @lines = grep(!/${penguin_chiefs}/i, @lines);
		}

		last if !@lines;

		my @authors = ();
		foreach my $line (@lines) {
		    if ($line =~ m/$VCS_cmds{"author_pattern"}/) {
			my $author = $1;
			$author = deduplicate_email($author);
			push(@authors, $author);
		    }
		}

		save_commits_by_author(@lines) if ($interactive);
		save_commits_by_signer(@lines) if ($interactive);

		push(@signers, @authors);
	    }}
	    else {
		foreach my $commit (@commits) {
		    my $i;
		    my $cmd = $VCS_cmds{"find_commit_author_cmd"};
		    $cmd =~ s/(\$\w+)/$1/eeg;	#interpolate $cmd
		    my @author = vcs_find_author($cmd);
		    next if !@author;

		    my $formatted_author = deduplicate_email($author[0]);

		    my $count = grep(/$commit/, @all_commits);
		    for ($i = 0; $i < $count ; $i++) {
			push(@blame_signers, $formatted_author);
		    }
		}
	    }
	    if (@blame_signers) {
		vcs_assign("authored lines", $total_lines, @blame_signers);
	    }
	}
	foreach my $signer (@signers) {
	    $signer = deduplicate_email($signer);
	}
	vcs_assign("commits", $total_commits, @signers);
    } else {
	foreach my $signer (@signers) {
	    $signer = deduplicate_email($signer);
	}
	vcs_assign("modified commits", $total_commits, @signers);
    }
}

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

    my $exists;

    my $vcs_used = vcs_exists();
    return 0 if (!$vcs_used);

    my $cmd = $VCS_cmds{"file_exists_cmd"};
    $cmd =~ s/(\$\w+)/$1/eeg;		# interpolate $cmd
    $cmd .= " 2>&1";
    $exists = &{$VCS_cmds{"execute_cmd"}}($cmd);

    return 0 if ($? != 0);

    return $exists;
}

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

    my @lsfiles = ();

    my $vcs_used = vcs_exists();
    return 0 if (!$vcs_used);

    my $cmd = $VCS_cmds{"list_files_cmd"};
    $cmd =~ s/(\$\w+)/$1/eeg;   # interpolate $cmd
    @lsfiles = &{$VCS_cmds{"execute_cmd"}}($cmd);

    return () if ($? != 0);

    return @lsfiles;
}

sub uniq {
    my (@parms) = @_;

    my %saw;
    @parms = grep(!$saw{$_}++, @parms);
    return @parms;
}

sub sort_and_uniq {
    my (@parms) = @_;

    my %saw;
    @parms = sort @parms;
    @parms = grep(!$saw{$_}++, @parms);
    return @parms;
}

sub clean_file_emails {
    my (@file_emails) = @_;
    my @fmt_emails = ();

    foreach my $email (@file_emails) {
	$email =~ s/[\(\<\{]{0,1}([A-Za-z0-9_\.\+-]+\@[A-Za-z0-9\.-]+)[\)\>\}]{0,1}/\<$1\>/g;
	my ($name, $address) = parse_email($email);
	if ($name eq '"[,\.]"') {
	    $name = "";
	}

	my @nw = split(/[^A-Za-zÀ-ÿ\'\,\.\+-]/, $name);
	if (@nw > 2) {
	    my $first = $nw[@nw - 3];
	    my $middle = $nw[@nw - 2];
	    my $last = $nw[@nw - 1];

	    if (((length($first) == 1 && $first =~ m/[A-Za-z]/) ||
		 (length($first) == 2 && substr($first, -1) eq ".")) ||
		(length($middle) == 1 ||
		 (length($middle) == 2 && substr($middle, -1) eq "."))) {
		$name = "$first $middle $last";
	    } else {
		$name = "$middle $last";
	    }
	}

	if (substr($name, -1) =~ /[,\.]/) {
	    $name = substr($name, 0, length($name) - 1);
	} elsif (substr($name, -2) =~ /[,\.]"/) {
	    $name = substr($name, 0, length($name) - 2) . '"';
	}

	if (substr($name, 0, 1) =~ /[,\.]/) {
	    $name = substr($name, 1, length($name) - 1);
	} elsif (substr($name, 0, 2) =~ /"[,\.]/) {
	    $name = '"' . substr($name, 2, length($name) - 2);
	}

	my $fmt_email = format_email($name, $address, $email_usename);
	push(@fmt_emails, $fmt_email);
    }
    return @fmt_emails;
}

sub merge_email {
    my @lines;
    my %saw;

    for (@_) {
	my ($address, $role) = @$_;
	if (!$saw{$address}) {
	    if ($output_roles) {
		push(@lines, "$address ($role)");
	    } else {
		push(@lines, $address);
	    }
	    $saw{$address} = 1;
	}
    }

    return @lines;
}

sub output {
    my (@parms) = @_;

    if ($output_multiline) {
	foreach my $line (@parms) {
	    print("${line}\n");
	}
    } else {
	print(join($output_separator, @parms));
	print("\n");
    }
}

my $rfc822re;

sub make_rfc822re {
#   Basic lexical tokens are specials, domain_literal, quoted_string, atom, and
#   comment.  We must allow for rfc822_lwsp (or comments) after each of these.
#   This regexp will only work on addresses which have had comments stripped
#   and replaced with rfc822_lwsp.

    my $specials = '()<>@,;:\\\\".\\[\\]';
    my $controls = '\\000-\\037\\177';

    my $dtext = "[^\\[\\]\\r\\\\]";
    my $domain_literal = "\\[(?:$dtext|\\\\.)*\\]$rfc822_lwsp*";

    my $quoted_string = "\"(?:[^\\\"\\r\\\\]|\\\\.|$rfc822_lwsp)*\"$rfc822_lwsp*";

#   Use zero-width assertion to spot the limit of an atom.  A simple
#   $rfc822_lwsp* causes the regexp engine to hang occasionally.
    my $atom = "[^$specials $controls]+(?:$rfc822_lwsp+|\\Z|(?=[\\[\"$specials]))";
    my $word = "(?:$atom|$quoted_string)";
    my $localpart = "$word(?:\\.$rfc822_lwsp*$word)*";

    my $sub_domain = "(?:$atom|$domain_literal)";
    my $domain = "$sub_domain(?:\\.$rfc822_lwsp*$sub_domain)*";

    my $addr_spec = "$localpart\@$rfc822_lwsp*$domain";

    my $phrase = "$word*";
    my $route = "(?:\@$domain(?:,\@$rfc822_lwsp*$domain)*:$rfc822_lwsp*)";
    my $route_addr = "\\<$rfc822_lwsp*$route?$addr_spec\\>$rfc822_lwsp*";
    my $mailbox = "(?:$addr_spec|$phrase$route_addr)";

    my $group = "$phrase:$rfc822_lwsp*(?:$mailbox(?:,\\s*$mailbox)*)?;\\s*";
    my $address = "(?:$mailbox|$group)";

    return "$rfc822_lwsp*$address";
}

sub rfc822_strip_comments {
    my $s = shift;
#   Recursively remove comments, and replace with a single space.  The simpler
#   regexps in the Email Addressing FAQ are imperfect - they will miss escaped
#   chars in atoms, for example.

    while ($s =~ s/^((?:[^"\\]|\\.)*
                    (?:"(?:[^"\\]|\\.)*"(?:[^"\\]|\\.)*)*)
                    \((?:[^()\\]|\\.)*\)/$1 /osx) {}
    return $s;
}

#   valid: returns true if the parameter is an RFC822 valid address
#
sub rfc822_valid {
    my $s = rfc822_strip_comments(shift);

    if (!$rfc822re) {
        $rfc822re = make_rfc822re();
    }

    return $s =~ m/^$rfc822re$/so && $s =~ m/^$rfc822_char*$/;
}

#   validlist: In scalar context, returns true if the parameter is an RFC822
#              valid list of addresses.
#
#              In list context, returns an empty list on failure (an invalid
#              address was found); otherwise a list whose first element is the
#              number of addresses found and whose remaining elements are the
#              addresses.  This is needed to disambiguate failure (invalid)
#              from success with no addresses found, because an empty string is
#              a valid list.

sub rfc822_validlist {
    my $s = rfc822_strip_comments(shift);

    if (!$rfc822re) {
        $rfc822re = make_rfc822re();
    }
    # * null list items are valid according to the RFC
    # * the '1' business is to aid in distinguishing failure from no results

    my @r;
    if ($s =~ m/^(?:$rfc822re)?(?:,(?:$rfc822re)?)*$/so &&
	$s =~ m/^$rfc822_char*$/) {
        while ($s =~ m/(?:^|,$rfc822_lwsp*)($rfc822re)/gos) {
            push(@r, $1);
        }
        return wantarray ? (scalar(@r), @r) : 1;
    }
    return wantarray ? () : 0;
}