bind-9.11.3/util/update_copyrights

9d129b55f5a43abf43865c6b0eb6dd19bc22aba8ianh#!/usr/local/bin/perl -w
759f4a24d09e28c4eaca9f97311b497fc15cb5c7ben#
9d129b55f5a43abf43865c6b0eb6dd19bc22aba8ianh# Copyright (C) 1998-2001, 2004-2010, 2012-2017  Internet Systems Consortium, Inc. ("ISC")
9d129b55f5a43abf43865c6b0eb6dd19bc22aba8ianh#
759f4a24d09e28c4eaca9f97311b497fc15cb5c7ben# This Source Code Form is subject to the terms of the Mozilla Public
759f4a24d09e28c4eaca9f97311b497fc15cb5c7ben# License, v. 2.0. If a copy of the MPL was not distributed with this
759f4a24d09e28c4eaca9f97311b497fc15cb5c7ben# file, You can obtain one at http://mozilla.org/MPL/2.0/.
759f4a24d09e28c4eaca9f97311b497fc15cb5c7ben
759f4a24d09e28c4eaca9f97311b497fc15cb5c7benrequire 5.002;
759f4a24d09e28c4eaca9f97311b497fc15cb5c7ben
9d129b55f5a43abf43865c6b0eb6dd19bc22aba8ianh# Map copyright owners to the files containing copyright messages.
9d129b55f5a43abf43865c6b0eb6dd19bc22aba8ianh# The first line of the copyright message is not in the file;
9d129b55f5a43abf43865c6b0eb6dd19bc22aba8ianh# it is constructed by this script.
9d129b55f5a43abf43865c6b0eb6dd19bc22aba8ianh#
9d129b55f5a43abf43865c6b0eb6dd19bc22aba8ianh# Usage:
da8aae9fd8c1e728c09df8433683e3b74f074066igalic#
da8aae9fd8c1e728c09df8433683e3b74f074066igalic#   perl util/update_copyrights <util/copyrights
da8aae9fd8c1e728c09df8433683e3b74f074066igalic
9d129b55f5a43abf43865c6b0eb6dd19bc22aba8ianhmy %owner2filename = (
78e15c62ea2659eb5b8ea41c642bfd74e1d471efrbb    "" => "util/COPYRIGHT",
759f4a24d09e28c4eaca9f97311b497fc15cb5c7ben    "NAI" => "util/COPYRIGHT.NAI",
78e15c62ea2659eb5b8ea41c642bfd74e1d471efrbb    "NOM" => "util/COPYRIGHT.NOM",
759f4a24d09e28c4eaca9f97311b497fc15cb5c7ben    "BSDI" => "util/COPYRIGHT.BSDI",
e7f5c5a9f5d30770a62b9804f76c7d36155d5260jailletc    "BRIEF" => "util/COPYRIGHT.BRIEF",
e7f5c5a9f5d30770a62b9804f76c7d36155d5260jailletc    "PORTION" => "util/COPYRIGHT.PORTION",
e7f5c5a9f5d30770a62b9804f76c7d36155d5260jailletc);
e7f5c5a9f5d30770a62b9804f76c7d36155d5260jailletc
78e15c62ea2659eb5b8ea41c642bfd74e1d471efrbb# Map each copyright owner name to a reference to an array containing
78e15c62ea2659eb5b8ea41c642bfd74e1d471efrbb# the lines of the copyright message.
78e15c62ea2659eb5b8ea41c642bfd74e1d471efrbb
9d129b55f5a43abf43865c6b0eb6dd19bc22aba8ianhmy %owner2text = ();
5a9609d43c25550fb107c4e312b2b0609129b2fcpoirier
78e15c62ea2659eb5b8ea41c642bfd74e1d471efrbbmy $keyword_pat = '\$(Id:.*|Revision:.*|Id|Revision)\$';
78e15c62ea2659eb5b8ea41c642bfd74e1d471efrbb
e7f5c5a9f5d30770a62b9804f76c7d36155d5260jailletcforeach $owner (keys %owner2filename) {
9d129b55f5a43abf43865c6b0eb6dd19bc22aba8ianh        my $f = $owner2filename{$owner};
972f5b1be57a9e67b775c7c9f39edb8a7bcdf394ianh        open(COPYRIGHT, "<$f") || die "can't open $f: $!";
972f5b1be57a9e67b775c7c9f39edb8a7bcdf394ianh        @copyright_text = <COPYRIGHT>;
972f5b1be57a9e67b775c7c9f39edb8a7bcdf394ianh        close(COPYRIGHT);
972f5b1be57a9e67b775c7c9f39edb8a7bcdf394ianh        $owner2text{$owner} = [ @copyright_text ];
972f5b1be57a9e67b775c7c9f39edb8a7bcdf394ianh}
972f5b1be57a9e67b775c7c9f39edb8a7bcdf394ianh
972f5b1be57a9e67b775c7c9f39edb8a7bcdf394ianhmy %file_types = ();
972f5b1be57a9e67b775c7c9f39edb8a7bcdf394ianhmy %file_years = ();
972f5b1be57a9e67b775c7c9f39edb8a7bcdf394ianhmy $years_list;
972f5b1be57a9e67b775c7c9f39edb8a7bcdf394ianhmy $parent;
972f5b1be57a9e67b775c7c9f39edb8a7bcdf394ianh
972f5b1be57a9e67b775c7c9f39edb8a7bcdf394ianh($dummy,$dummy,$dummy,$dummy,$this_month,$this_year,$dummy,$dummy,$dummy) = localtime(time());
972f5b1be57a9e67b775c7c9f39edb8a7bcdf394ianh$this_year += 1900;
972f5b1be57a9e67b775c7c9f39edb8a7bcdf394ianh
972f5b1be57a9e67b775c7c9f39edb8a7bcdf394ianhwhile (<>) {
972f5b1be57a9e67b775c7c9f39edb8a7bcdf394ianh    chomp;
972f5b1be57a9e67b775c7c9f39edb8a7bcdf394ianh    ($file, $type, $years) = split(/\s+/);
972f5b1be57a9e67b775c7c9f39edb8a7bcdf394ianh    $file_types{$file} = $type;
972f5b1be57a9e67b775c7c9f39edb8a7bcdf394ianh    $file_years{$file} = $years;
972f5b1be57a9e67b775c7c9f39edb8a7bcdf394ianh}
972f5b1be57a9e67b775c7c9f39edb8a7bcdf394ianh
972f5b1be57a9e67b775c7c9f39edb8a7bcdf394ianhsub getyears {
ab86c68ce36c715e93f403dde41d0b9c1522c8b0sf    $parent = $_[0];
ab86c68ce36c715e93f403dde41d0b9c1522c8b0sf    $parent =~ s/PARENT://;
ab86c68ce36c715e93f403dde41d0b9c1522c8b0sf    $years_list = $file_years{$parent};
c779aea0c9b7c47c2e4fd258e3f54835a849625dpoirier    if (defined($years_list) && $years_list =~ /^PARENT:/) {
c779aea0c9b7c47c2e4fd258e3f54835a849625dpoirier        print "BAD PARENT:$parent\n";
e7f5c5a9f5d30770a62b9804f76c7d36155d5260jailletc        undefine($years_list);
e7f5c5a9f5d30770a62b9804f76c7d36155d5260jailletc    }
e7f5c5a9f5d30770a62b9804f76c7d36155d5260jailletc}
c779aea0c9b7c47c2e4fd258e3f54835a849625dpoirier
759f4a24d09e28c4eaca9f97311b497fc15cb5c7bensub docbook {
759f4a24d09e28c4eaca9f97311b497fc15cb5c7ben    $parent = $_[0];
0432a26b69eedfb9ca5f34fba590236378a24851ben    $parent =~ s/\.[^.]*$/.docbook/;
35a32eef1294a01af9e7daa9ce2cd0f57908cd0asctemme    $years_list = $file_years{$parent};
a2976e8524b1efa5ec50aea83695e3000f024c35jailletc}
35a32eef1294a01af9e7daa9ce2cd0f57908cd0asctemme
0432a26b69eedfb9ca5f34fba590236378a24851bensub copyright {
0432a26b69eedfb9ca5f34fba590236378a24851ben    my $holder = shift;
9d129b55f5a43abf43865c6b0eb6dd19bc22aba8ianh    my $result = "";
9d129b55f5a43abf43865c6b0eb6dd19bc22aba8ianh    return $result unless (@_);
9d129b55f5a43abf43865c6b0eb6dd19bc22aba8ianh    $result = "$result    <copyright>\n";
9d129b55f5a43abf43865c6b0eb6dd19bc22aba8ianh    $result = "$result      <year>$_</year>\n" foreach (@_);
    $result = "$result      <holder>$holder</holder>\n";
    $result = "$result    </copyright>\n";
    return $result;
}

sub copyrights {
    my $a = copyright("Internet Systems Consortium, Inc. (\"ISC\")", @_);
    return "$a";
}

foreach $file (keys %file_types) {
    $typeandowner = $file_types{$file};
    $years_list = $file_years{$file};

        if ( ! -f $file ) {
                print "$file: missing\n";
                next;
        }
    # print "Doing: $file";

        if ($years_list =~ /PARENT:/) {
        getyears($years_list);
        if (!defined $years_list) {
            print "$file: has bad parent $parent\n";
            next;
        }
    }

    # copyright notice is now generated from the source.
    next if ($years_list eq "DOCBOOK");

    if ($years_list eq "DOCBOOK") {
        docbook($file);
        if (!defined $years_list) {
            print "$file: has bad parent $parent\n";
            next;
        }
    }

        @years = split(/,/, $years_list);

        my ($type, $owner) = split(/\./, $typeandowner);
        $owner = "" if !defined $owner;

        $textp = $owner2text{$owner};
        if (!defined $textp) {
                print "$file: unknown copyright owner $owner\n";
                next;
        }

    if ($file eq "./CHANGES" || $file eq "./EXCLUDED" ||
        $file eq "./CHANGES.SE")
    {
        open(SOURCE, "<$file") || die "can't open $file: $!";
        my $body = "";
        while (<SOURCE>) {
        # Process leading white space.
        # Remove 1-7 spaces followed by a tab into a single
        # tab if at start of line or proceeded by tabs.
        s/^(\t*) {1,7}\t/$1\t/ while (/^\t* {1,7}\t/);
        s/^(\s{0,3}\d*\.)\s(\[\w{1,5}\])\s+(\S+)/$1\t$2\t\t$3/;
        s/^(\s{0,3}\d*\.)\s(\[\w{6,}\])\s+(\S+)/$1\t$2\t$3/;
        # Convert 8 spaces into tabs if at start of line
        # or preceeded by tabs.
        s/^(\t*)        /$1\t/ while (/^\t*        /);
        # Remove trailing white space.
        s/[ \t]*$//;
            $body = "$body$_";
        }
        $_ = $body;
        open(TARGET, ">$file.new") || die "can't open $file.new: $!";
        print TARGET $_;
        close(TARGET);
        close(SOURCE);
        if (system("cmp -s $file.new $file") == 0) {
            unlink("$file.new");
        } else {
            rename("$file.new", "$file")
              or die "rename($file.new, $file): $!";
        }
    }

        next if $type eq "X" or $type eq "BAT";

        $before_copyright = "";
        $c_comment = 0;
        $shell_comment = 0;
        $m4_comment = 0;
        $sgml_comment = 0;
        $mkd_comment = 0;
        $zone_comment = 0;
        $man_comment = 0;
        $python_comment = 0;
        $python_bin_comment = 0;
        $start_comment = "";
        $end_comment = "";
        $first = "";
        if ($type =~ /^(C|YACC|CONF-C)$/) {
                $c_comment = 1;
                $start_comment = "/*\n";
                $prefix = " * ";
                $end_comment = " */\n";
        } elsif ($type =~ /^(SH|PERL|TCL|MAKE|CONF-SH|RNC)$/) {
                $shell_comment = 1;
        $prefix = "# ";
        } elsif ($type =~ /^PYTHON-BIN$/) {
                $python_bin_comment = 1;
                $start_comment = "############################################################################\n";
                $prefix = "# ";
        $end_comment = "############################################################################\n"
        } elsif ($type =~ /^PYTHON$/) {
                $python_comment = 1;
                $start_comment = "############################################################################\n";
                $prefix = "# ";
        $end_comment = "############################################################################\n"
        } elsif ($type eq "ZONE" || $type eq "MC") {
                $zone_comment = 1;
                $prefix = "; ";
        } elsif ($type eq "MAN") {
                $man_comment = 1;
                $prefix = ".\\\" ";
        } elsif ($type eq "M4") {
                $m4_comment = 1;
                $prefix = "dnl ";
        } elsif ($type eq "HTML" || $type eq "SGML") {
                $sgml_comment = 1;
                $start_comment = "<!--\n";
                $prefix = " - ";
                $end_comment = "-->\n";
        } elsif ($type eq "MKD") {
                $mkd_comment = 1;
                $start_comment = "<!--\n";
                $prefix = " - ";
                $end_comment = "-->";
        } elsif ($type eq "TXT") {
                $prefix = "";
        } else {
                print "$file: type '$type' not supported yet; skipping\n";
                next;
        }

        ($nonspaceprefix = $prefix) =~ s/\s+$//;

        open(SOURCE, "<$file") || die "can't open $file: $!";
        $_ = <SOURCE>;
        if ($type eq "YACC") {
                unless ($_ eq "%{\n") {
                        print "$file: unexpected yacc file start ",
                              "(expected \"%{\\n\")\n";
                        close(SOURCE);
                        next;
                }
                $before_copyright = "$_";
                $_ = <SOURCE>;
        }
        if ($c_comment && /^\/\*/) {
                $_ = <SOURCE>;
                if ($_ !~ /[Cc]opyright/) {
                        print "$file: non-copyright comment\n";
                        close(SOURCE);
                        next;
                }
                if ($_ !~ /\*\//) {
                        while (<SOURCE>) {
                                last if $_ =~ /\*\//;
                        }
                }
        } elsif ($shell_comment) {
                if (/^\#\!/) {
                        $before_copyright = "$_#\n";
                        $_ = <SOURCE>;
                        $_ = <SOURCE> if $_ eq "#\n";
                }
                if (/^\#/) {
                        if ($_ !~ /[Cc]opyright/) {
                                print "$file: non-copyright comment\n";
                                close(SOURCE);
                                next;
                        }
                        while (<SOURCE>) {
                                if ($_ !~ /^\#/) {
                                        $first = $_;
                                        last;
                                }
                        }
                } else {
                        $first = $_;
                }
        } elsif ($python_comment || $python_bin_comment) {
                if ($python_bin_comment && /^\#\!/) {
                        $before_copyright = "$_";
                        $_ = <SOURCE>;
                        $_ = <SOURCE> if $_ eq "#\n";
                        $_ = <SOURCE> if $_ eq "############################################################################\n";
                } elsif ($python_comment && /^\#/) {
                        $_ = <SOURCE> if $_ eq "#\n";
                        $_ = <SOURCE> if $_ eq "############################################################################\n";
                }
                if (/^\#/) {
                        if ($_ !~ /[Cc]opyright/) {
                                print "$file: non-copyright comment\n";
                                close(SOURCE);
                                next;
                        }
                        while (<SOURCE>) {
                                if ($_ !~ /^\#/) {
                                        $first = $_;
                                        last;
                                }
                        }
                } else {
                        $first = $_;
                }
        } elsif (($m4_comment || $zone_comment || $man_comment) &&
                 /^\Q$nonspaceprefix\E/) {

                while (/^\Q$nonspaceprefix\E\s*$/) {
                        $_ = <SOURCE>;
                }

                if ($_ !~ /[Cc]opyright/) {
                        print "$file: non-copyright comment\n";
                        close(SOURCE);
                        next;
                }
                while (<SOURCE>) {
                        if ($_ !~ /^\Q$nonspaceprefix\E/ ||
                            $_ =~ /$keyword_pat/) {
                                $first = $_;
                                last;
                        }
                }
        } elsif ($sgml_comment) {
        $before_copyright = "";
                while (/^<!DOCTYPE/ || /^<!ENTITY/ || /^<\?xml-stylesheet/ || /^<\?xml /) {
            # print "SGML: $_";
            $before_copyright = "$before_copyright$_";
            if (/\]>$/ ) {
                $_ = <SOURCE>;
                close(SOURCE) if (eof(SOURCE));
                next;
            }
            if (/^<!DOCTYPE.*\[$/) {
                while (!eof(SOURCE)) {
                    $_ = <SOURCE>;
                    next if (eof(SOURCE));
                    $before_copyright =
                         "$before_copyright$_";
                    if (/]>$/) {
                        $_ = <SOURCE>;
                        last;
                    }
                }
                close(SOURCE) if (eof(SOURCE));
                next;
            }
            if (/>$/ ) {
                $_ = <SOURCE>;
                close(SOURCE) if (eof(SOURCE));
                next;
            }
            $_ = <SOURCE>;
            while (!eof(SOURCE) && ! /^<!/ ) {
                $before_copyright = "$before_copyright$_";
                $_ = <SOURCE>;
            }
            if (eof(SOURCE)) {
                close(SOURCE);
                next;
            }
                }
                if (/^<!--/) {
                        $_ = <SOURCE> if $_ eq "<!--\n";
                        if ($_ !~ /[Cc]opyright/) {
                                print "$file: non-copyright comment\n";
                                close(SOURCE);
                                next;
                        }
                        while (defined($_)) {
                                last if s/.*-->//;
                                $_ = <SOURCE>;
                        }
                        print "$file: unterminated comment\n"
                          unless defined($_);
                        if ($_ ne "\n") {
                                $first = $_;
                        } else {
                                $first = <SOURCE>;
                        }
                } else {
                        $first = $_;
                }
        } elsif ($mkd_comment) {
        $before_copyright = "";
                if (/^<!/) {
                        $_ = <SOURCE> if $_ eq "<!--\n";
                        if ($_ !~ /[Cc]opyright/) {
                                print "$file: non-copyright comment\n";
                                close(SOURCE);
                                next;
                        }
                        while (defined($_)) {
                                last if s/.*-->//;
                                $_ = <SOURCE>;
                        }
                        print "$file: unterminated comment\n"
                          unless defined($_);
                        if ($_ ne "\n") {
                                $first = $_;
                        } else {
                                $first = <SOURCE>;
                        }
                } else {
                        $first = $_;
                }
        } elsif ($type eq "TXT") {
                if ($_ =~ /[Cc]opyright/) {
                        $/ = "";            # paragraph at a time
                        while (<SOURCE>) {
                                # Not very maintainable, but ok enough for now.
                last if /Portions of this code/;
                                last unless
                                  /[Cc]opyright/ ||
                  /This Source Code Form is subject to the terms of the Mozilla Public/ ||
                  /If a copy of the MPL was not distributed with this/ ||
                  /You can obtain one at http:\/\/mozilla.org\/MPL\/2.0\// ||
                                  /See COPYRIGHT in the source root/ ||
                                  /Permission to use, copy, modify, and / ||
                                  /THE SOFTWARE IS PROVIDED "AS IS" AND /;
                        }
                        $/ = "\n";
                }
                $first = $_;
        } else {
                $first = $_;
        }

        $first = "" if ! defined($first);

        open(TARGET, ">$file.new") || die "can't open $file.new: $!";
        print TARGET $before_copyright if $before_copyright;
        print TARGET $start_comment if $start_comment;

        $sysyears = "";
        $nomyears = "";

    #
    # Nominum: up to 2001.
    #
        $last_year = 0;
        $anchor_year = 0;
    $years = "";
        foreach $year (@years) {
        if ($year >= 2002) { next; }
                if ($last_year != 0 && $year == $last_year + 1) {
                        if ($year > $anchor_year + 1) {
                                substr($years, $anchor_end) = "-$year";
                        } else {
                                $years .= ", $year";
                        }
                } else {
                        $years .= $last_year == 0 ? "$year" : ", $year";
                        #if ($anchor_year != 0) {
                        #        print "$file: noncontiguous year: ",
                        #              "$year != $last_year + 1\n";
                        #}
                        $anchor_year = $year;
                        $anchor_end = length($years);
                }

                $last_year = $year;
        }
    $nomyears = $years;

    #
    # Internet Systems Consortium: 2004 onwards.
    #
        $last_year = 0;
        $anchor_year = 0;
    $years = "";
    $anchor_end = length($years);
    my $andor = 0;
    my $noid = 0;
        foreach $year (@years) {
        $andor = 1 if ($year >= 2007);
        $noid = 1 if ($year > 2012 || ($year == 2012 && $this_month >= 5) );
                if ($last_year != 0 && $year == $last_year + 1) {
                        if ($year > $anchor_year + 1) {
                                substr($years, $anchor_end) = "-$year";
                        } else {
                                $years .= ", $year";
                        }
                } else {
                        $years .= $last_year == 0 ? "$year" : ", $year";
                        #if ($anchor_year != 0) {
                        #        print "$file: noncontiguous year: ",
                        #              "$year != $last_year + 1\n";
                        #}
                        $anchor_year = $year;
                        $anchor_end = length($years);
                }

                $last_year = $year;
        }
    $sysyears = $years;

    # make a copy
        @lines = @$textp;

        foreach $_ (@lines) {
        next if (/\@SYSYEARS\@/ && $sysyears eq "");
        s:modify, and distribute:modify, and/or distribute: if ($andor);
                print TARGET (/^$/ ? $nonspaceprefix : $prefix);
        s/\@SYSYEARS\@/$sysyears/;
        s/\@NOMYEARS\@/$nomyears/;
                print TARGET "$_";
        }
        print TARGET $end_comment if $end_comment;

        if ($first eq "") {
                $first = <SOURCE>;
        }

        if (defined($first)) {
            if ($type eq 'MAN') {
                    print TARGET "$nonspaceprefix\n";
        } else {
                    print TARGET "\n";
                }

        if (($type eq "C" || $type eq "CONF-C") &&
            $sysyears =~ /$this_year/) {
            my $body = "";
            while (<SOURCE>) {
            # Process leading white space.
            # Remove 1-7 spaces followed by a tab into a single
            # tab if at start of line or proceeded by tabs.
            s/^(\t*) {1,7}\t/$1\t/ while (/^\t* {1,7}\t/);
            # Convert 8 spaces into tabs if at start of line
            # or preceeded by tabs.
            s/^(\t*) {8}/$1\t/ while (/^\t* {8}/);
            # Remove trailing white space.
            s/[ \t]*$//;
                $body = "$body$_";
            }
            $_ = $body;
        } elsif (($type eq "SGML" || $type eq "HTML" ||
              $type eq "MAKE") &&
                 $sysyears =~ /$this_year/) {
            my $body = "";
            while (<SOURCE>) {
            # Remove trailing white space.
            s/[ \t]*$//;
                $body = "$body$_";
            }
            $_ = $body;
        } else {
            undef $/;
            $_ = <SOURCE>;
            $/ = "\n";
        }

        if ($type eq 'SGML' && m:<articleinfo>.*?</articleinfo>:s) {
            # print "docinfo: $file\n";
            my $r = copyrights(@years);
            s:<articleinfo>.*?</articleinfo>:<articleinfo>\n$r  </articleinfo>:s;
        }
        if ($type eq 'SGML' && m:<docinfo>.*?</docinfo>:s) {
            # print "docinfo: $file\n";
            my $r = copyrights(@years);
            s:<docinfo>.*?</docinfo>:<docinfo>\n$r  </docinfo>:s;
        }
        if ($type eq 'SGML' && m:<bookinfo>.*?</bookinfo>:s) {
            # print "bookinfo: $file\n";
            my $r = copyrights(@years);
            $r .= "    <xi:include href=\"releaseinfo.xml\"/>\n";
            s:<bookinfo>.*?</bookinfo>:<bookinfo>\n$r  </bookinfo>:s;
        }
        if ($type eq 'SGML' && m:<!-- insert copyright start -->.*?<!-- insert copyright end -->:s) {
            my $r = copyrights(@years);
            s:<!-- insert copyright start -->.*?<!-- insert copyright end -->:<!-- insert copyright start -->\n$r    <!-- insert copyright end -->:s;
        }

                my ($start, $end);
        if ($type =~ /^PYTHON(|-BIN)$/) {
                        ($start = $prefix) =~ s/\s*\n//;
            $end = "\n";
                } elsif ($start_comment ne "") {
                        ($start = $start_comment) =~ s/\s*\n/ /;
                        ($end = $end_comment) =~ s/^\s*(.*)\n/ $1\n/;
                } elsif ($prefix ne "") {
                        ($start = $prefix) =~ s/\s*\n//;
                        $end = "\n";
                } else {
                        $start = "";
                        $end = "\n";
                }

                if (!$noid && $first !~ /$keyword_pat/ &&
            (!defined($_) || $_ !~ /$keyword_pat/)) {
            $end = "\n$nonspaceprefix" if ($type eq "MAN");
                        print TARGET "$start\$";
                        print TARGET "Id";
                        print TARGET "\$$end\n";
                }

                print TARGET $first if $first !~ /^\s*$/;
                print TARGET $_ if (defined($_));
        }
        close(TARGET);
        close(SOURCE);

        $mode = (stat $file)[2]&511;
        chmod $mode, "$file.new";

        if (system("cmp -s $file.new $file") == 0) {
                unlink("$file.new");
        } else {
                rename("$file.new", "$file")
                  or die "rename($file.new, $file): $!";
        }
}