nicktrace hexchat script (not mine)

#!/usr/bin/perl
use warnings;

my $sname="DMS-Nick-Trace";
my $version="1.5.0";

Xchat::register($sname, $version, "DMS");

my $outputType=-1; #0=Join Message, 1=Notice, 2=Server Notice
my $lessOut=0;
my $autoAdd=1;
my $hostmasks=Xchat::get_info("xchatdir");

$hostmasks="$hostmasks/addons/hostmasks.db";

Xchat::hook_print('Join', 'joinHandler',{help_text => 'handles nickchanges'});
Xchat::hook_server('NICK','nickHandler',{help_text => 'handles joins'});
Xchat::hook_command('NickTrace','nicktraceHandler',{help_text => 'check for aliases for given nick'});
Xchat::hook_command('NickTrace_add','nicktraceAddHandler',{help_text => 'usage: /NickTrace_add NICK IDENT HOST/IP'});

sub readFile{
    $path=shift(@_);
    #if (open(DB, "<","$path")==undef){Xchat::print("file not found: $path");return "";}
    if (!open(DB, "<","$path")){Xchat::print("file not found: $path");return "";}
    @stats=stat(DB);
    my $data;
    read (DB,$data,$stats[7]);
    close (DB);
    return $data;
}

sub nicktraceHandler{
    $nick=$_[0][1];
    if (!$nick){Xchat::print("you have to give nick as argument");return Xchat::EAT_ALL;}
    my $data=Xchat::user_info("$nick");
    if (!$data){
        Xchat::print("invalid user");
        return Xchat::EAT_ALL;
    }
    $host=$data->{"host"};
    @parts=split("@",$host);
    $akas=checkAlias($nick,$parts[0],$parts[1]);
    Xchat::printf("$nick$akas");
    return Xchat::EAT_ALL;
}


sub checkAlias{
    $nick=shift(@_);
    $ident=shift(@_);
    $hostmask=shift(@_);
    $aliases="";
    foreach $line (split "\n", readFile($hostmasks)){
        my($n, $i, $h)=(split "=", $line);
        if (($i eq $ident)||($h eq $hostmask)){
            if ($n ne $nick){
                if (($i eq $ident)&&($h eq $hostmask)){$aliases="$aliases aka. $n" if (index($aliases,"aka. $n")==-1);}
                else {if ($lessOut==1){$aliases="$aliases (aka. $n)" if (index($aliases,"aka. $nick")==-1);}}
            }
        }
    }
    return $aliases;
}

sub addAlias{
    $nick=shift(@_);
    $ident=shift(@_);
    $hostmask=shift(@_);
    $db=readFile($hostmasks);
    open(DB, ">$hostmasks");
    foreach $line(split "\n", $db){
        my($n,$i, $h)=(split "=", $line);
        print DB "$n=$i=$h\n" if (($n ne $nick)||($i ne $ident)||($h ne $hostmask));
    }
    print DB "$nick=$ident=$hostmask\n";
    close(DB);
}

sub nicktraceAddHandler{addAlias($_[0][1],$_[0][2],$_[0][3]);Xchat::print("Added to hostmask.db");return Xchat::EAT_ALL;}

sub joinHandler{
    $mask=$_[0][2];
    $nick=$_[0][0];
    $chan=$_[0][1];
    if (index($nick,"\002\002")==0){return Xchat::EAT_NONE;}
    @parts2=split("@",$mask);
    $ident=$parts2[0];
    $hostmask=$parts2[1];
    $alias=checkAlias($nick,$ident,$hostmask);
    &addAlias($nick,$ident,$hostmask)if ($autoAdd==1);
    if ($outputType==0){
        my @ret=();
        push(@ret,"\002\002$nick$alias");push(@ret,$chan);push(@ret,"$mask");
        $rVal=Xchat::emit_print('Join',@ret);
        if ($rVal!=1){ #emit_print fails (why ever)
            Xchat::print("emit_print failed (returned $rVal)");
            Xchat::print("\002$nick$alias\002 ($mask) has joined $chan");
        }
        return Xchat::EAT_ALL;
    }
    if ($outputType==1){ #notice
        my @ret=();
        push(@ret,"nickTrace");push(@ret,"\002\002$nick$alias");
        Xchat::set_context("(notices)");
        $rVal=Xchat::emit_print('Notice',@ret);
        if ($rVal!=1){ #emit_print fails (why ever)
            Xchat::print("emit_print failed (returned $rVal)");
            #Xchat::print("\002$nick$alias\002 ($mask) has joined $chan");
        }
    }
    if ($outputType==2){ #server notice
        my @ret=();
        push(@ret,"\002\002$nick$alias");push(@ret,"nickTrace");
        Xchat::set_context("(snotices)");
        $rVal=Xchat::emit_print('Server Notice',@ret);
        if ($rVal!=1){ #emit_print fails (why ever)
            Xchat::print("emit_print failed (returned $rVal)");
            #Xchat::print("\002$nick$alias\002 ($mask) has joined $chan");
        }
    }

    return Xchat::EAT_NONE;
}

sub nickHandler{
    $mask=$_[0][0];
    $nick=substr($_[0][2],1);
    @parts1=split("!",$mask);
    @parts2=split("@",$parts1[1]);
    $ident=$parts2[0];
    $hostmask=$parts2[1];
    addAlias($nick,$ident,$hostmask);
    return Xchat::EAT_NONE;
}