#!@PERL@
#
# getlinks.pl
#
# This script extracts all links from a HTML page, compares them to a pattern
# entered on the command line and then downloads matching links into the
# target dir (also specified on the command line).
#
# Written to use 'curl' for URL fetching, uses the source file names in the
# target directory.
#
# Author: Daniel Stenberg <Daniel.Stenberg@sth.frontec.se>
# Version: 0.1 Oct 7, 1998
#
# HISTORY
#
# 0.1 - Created now!
#

$in="";

 argv:
if($ARGV[0] eq "-v" ) {
    $verbose = 1;
    shift @ARGV;
    goto argv;
}
if($ARGV[0] eq "-d" ) {
    $display = 1;
    shift @ARGV;
    goto argv;
}
elsif($ARGV[0] eq "-h" ) {
    $help = 1;
    shift @ARGV;
    goto argv;
}

$geturl = $ARGV[0];
$getdir = $ARGV[1];
$getregex = $ARGV[2];

if(($geturl eq "") ||
   (($getdir eq "") && !$display) ||
   $help) {
    print  "Usage: $0 [-hv] <full source URL> <target dir> [regex]\n",
    " Use a traling slash for directory URLs!\n",
    " Use \"quotes\" around the regex!\n",
    " -h  This help text\n",
    " -d  Display matches only instead of downloading\n",
    " -v  Verbose mode\n";
    exit;
}

# change to target directory:
chdir $getdir ||
    die "couldn't cd into $getdir";

# This is necessary from where I tried this:
#$proxy =" -x 194.237.142.41:80";

# linkchecker, URL will be appended to the right of this command line
# this is the one using HEAD:
$linkcheck = "curl -s -m 20 -I$proxy";

# as a second attempt, this will be used. This is not using HEAD but will
# get the whole frigging document!
$linkcheckfull = "curl -s -m 20 -i$proxy";

# htmlget, URL will be appended to the right of this command line
$htmlget = "curl -s$proxy";

# urlget, URL will be appended to the right of this command line
# this stores the file with the remote file name in the current dir
$urlget = "curl -O -s$proxy";

# Parse the input URL and split it into the relevant parts:

sub SplitURL {
    my $inurl = $_[0];

    if($inurl=~ /^([^:]+):\/\/([^\/]*)\/(.*)\/(.*)/ ) {
        $getprotocol = $1;
        $getserver = $2;
        $getpath = $3;
        $getdocument = $4;
    }
    elsif ($inurl=~ /^([^:]+):\/\/([^\/]*)\/(.*)/ ) {
        $getprotocol = $1;
        $getserver = $2;
        $getpath = $3;
        $getdocument = "";
    
        if($getpath !~ /\//) {
            $getpath ="";
            $getdocument = $3;
        }

    }
    elsif ($inurl=~ /^([^:]+):\/\/(.*)/ ) {
        $getprotocol = $1;
        $getserver = $2;
        $getpath = "";
        $getdocument = "";
    }
    else {
        print "Couldn't parse the specified URL, retry please!\n";
        exit;
    }
}

&SplitURL($geturl);

#print "protocol = $getprotocol\n";
#print "server = $getserver\n";
#print "path = $getpath\n";
#print "document = $getdocument\n";
#exit;

if(!$usestdin) {
    open(HEADGET, "$linkcheck $geturl|") ||
        die "Couldn't get web page for some reason";
  headget:
    while(<HEADGET>) {
#       print $_;
        if($_ =~ /HTTP\/.*3\d\d /) {
            $pagemoved=1;
        }
        elsif($pagemoved &&
               ($_ =~ /^Location: (.*)/)) {
            $geturl = $1;

            &SplitURL($geturl);

            $pagemoved++;
            last headget;
        }
    }
    close(HEADGET);

    if($pagemoved == 1) {
        print "Page is moved but we don't know where. Did you forget the ",
            "traling slash?\n";
        exit;
    }

    open(WEBGET, "$htmlget $geturl|") ||
        die "Couldn't get web page for some reason";

    while(<WEBGET>) {
        $line = $_;
        push @indoc, $line;
        $line=~ s/\n//g;
        $line=~ s/\r//g;
#       print $line."\n";
        $in=$in.$line;
    }

    close(WEBGET);
}
else {
    while(<STDIN>) {
        $line = $_;
        push @indoc, $line;
        $line=~ s/\n//g;
        $line=~ s/\r//g;
        $in=$in.$line;
    }
}

sub GetLinks {
    my $in = $_[0];
    my @result;

  getlinkloop:
    while($in =~ /[^<]*(<[^>]+>)/g ) {
        # we have a tag in $1
        $tag = $1;
    
        if($tag =~ /^<!--/) {
            # this is a comment tag, ignore it
        }
        else {
            if($tag =~ /(src|href|background|archive) *= *(\"[^\"]\"|[^ )>]*)/i) {
                $url=$2;
                if($url =~ /^\"(.*)\"$/) {
                    # this was a "string" now $1 has removed the quotes:
                    $url=$1;
                }


                $url =~ s/([^\#]*)\#.*/$1/g;

                if($url eq "") {
                    # if the link was nothing than a #-link it may now have
                    # been emptied completely so then we skip the rest
                    next getlinkloop;
                }

                if($done{$url}) {
                    # if this url already is done, do next
                    $done{$url}++;
                    next getlinkloop;
                }

                $done{$url} = 1; # this is "done"

                push @result, $url;
                if($tag =~ /< *([^ ]+)/) {
#                   print "TAG: $1\n";
                    $tagtype{$url}=$1;
                }
            }
        }
    }
    return @result;
}

@links = &GetLinks($in);

 linkloop:
for(@links) {
    $url = $_;

    if($url =~ /^([^:]+):/) {
        $link = $url;
    }
    else {
        # this is an absolute link on the same server:
        if($url =~ /^\//) {
            # from root
            $link = "$getprotocol://$getserver$url";
        }
        else {
            # from the scanned page's dir
            $nyurl=$url;

            if(length($getpath) &&
               ($getpath !~ /\/$/) &&
               ($nyurl !~ /^\//)) {
                # lacks ending slash, add one to the document part:
                $nyurl = "/".$nyurl;
            }
            $link = "$getprotocol://$getserver/$getpath$nyurl";
        }
    }

    if($link =~ /$getregex/) {
        if($display) {
            print "$link\n";
        }
        else {
            if($verbose) {
                print "Gets $link\n";
            }
            print `$urlget $link`;
        }
    }


}
