# setMyComputer.pl changes desktop 'My Computer' icon label to computer name
# and current user name via the registry, per tip in Windows 2000 Magazine 
# Security UPDATE, May 24, 2000 (from http://www.windows2000faq.com).
#
# Written 25-may-2000 by Frank Brown.
# Mod 07-jun-2000, fgb: run OS-specific code for NT 4.0 or W2K, based on
#   Windows version on target machine (determined by custom module rmtVer).
#
# usage: setMyComputer [machinelist.fil] [/v] [/deb]
#
# Notes:
# -----
# 1. Original version works on NT 4.0 machines only!
# 2. Changes registry entry type from REG_SZ to REG_EXPAND_SZ.
#
# Nothin' but perl, baby!

require "ctime.pl";
use Net::Ping;
use Win32::Registry;
use rmtVer;

# evil globals:

$bDebug = 0;
$sAppName = "setMyComputer";
$sDate = &ctime(time); chop $sDate;
$hk;
$sLocalMachine = Win32::NodeName;
$sMachine = "";
$sMachineList = "";
$sNow = time();
$bSingleMachine = 0;
$nTotalMachines = 0;
$bVerbose = 0;
$sVersion = "1.0";

MAIN:

ParseCmdArgs();

print "$sAppName $sVersion starting at $sDate...\n";
if ($sMachineList eq "") { 
  if (! $bSingleMachine) {
    $sMachine = $sLocalMachine;
    print "No list supplied; modifying local machine.\n";	# arf
    }
  if (-1 != &chRegVal()) { ++$nTotalMachines; }
  }
else { 
  open(FPCLIST,$sMachineList) || die "Can't open file $sMachineList: $!\n";

  while (<FPCLIST>) {
    if (!/^[\!\#;]/) {						# skip comments
      chop $_;
      s/\s(.*)//;						# remove whitespace
      s/^\\\\//;						# remove leading '\\'
      $sMachine = $_;
      if (&IsVisibleOnNet()) {
        if (-1 != &chRegVal()) { ++$nTotalMachines; }
        }
      }
    }
  close(FPCLIST);
  }
print "\n$sAppName: modified icon on $nTotalMachines machine";
if ($nTotalMachines != 1) { print "s."; }
exit;

# subroutines:

sub doNT40 {
  local $sValName = "";
  local $sNewVal = '%computername% / %username%';

  if ($bDebug) { print "dbg: SetValueEx($sValName,0,REG_EXPAND_SZ,$sNewVal)\n"; }
  else { 
    if (!$hk->SetValueEx($sValName,0,REG_EXPAND_SZ,$sNewVal)) { 
      if ($bVerbose) { print "error setting value for $sValName\n"; }
      }
    else { print "set\n"; }
    }
  }

sub doW2K {
  local $sValName = 'LocalizedString';
  local $sNewVal = "";
  local $sEnvStr = '%computername% / %username%';

  if ($bDebug) { print "dbg: QueryValue($sValName,$sNewVal)\n"; }
  if (!$hk->QueryValueEx($sValName,REG_SZ,$sNewVal)) {
    if ($bVerbose) { print "error getting value of $sValName\n"; }
    return -1;
    }
  $sNewVal =~ s/My Computer/$sEnvStr/;
  if ($bDebug) { print "dbg: new val = $sNewVal\n"; }
  if (!$hk->SetValueEx($sValName,0,REG_EXPAND_SZ,$sNewVal)) {
    if ($bVerbose) { print "error setting value for $sValName\n"; }
    }
  else { print "set\n"; }
  }

sub chRegVal {					### NT 4.0 only!
  local $sKey = "SOFTWARE\\Classes\\CLSID\\{20D04FE0-3AEA-1069-A2D8-08002B30309D}";
  local $hkr;
  local $sVer = rmtVer::getRemoteInfo($sMachine);

  $sServer = "\\\\" . $sMachine;		# used by Connect()
  print "Updating $sMachine...";

  $HKR = $main::HKEY_LOCAL_MACHINE;
  unless ($HKR->Connect($sServer,$hkr)) {
    print "Can't connect to $sServer; Win95?\n";
    return -1;
    }

  if (!$hkr->Open($sKey,$hk)) { print "error opening key $sKey\n"; return; }
  if ($sVer eq 'NT 4.0') { &doNT40(); }
  else { 
    if ($sVer eq 'Win2000') { &doW2K(); }
    else { print "Can't run on PC running $sVer\n"; }
    }

  $hk->Close();
  $hkr->Close();
  }

sub Help {
  printf("%s version %s\n",$sAppName,$sVersion);
  printf("\nusage: %s [machinelist.fil] [/v[erbose]]\n\n",$sAppName);
  print "machinelist.fil should be an ascii file with 1 machine per line.\n";
  print "If no machinelist is specified, current machine is modified.\n";
  }

sub IsVisibleOnNet {
  $p = Net::Ping->new("icmp");
  return ($p->ping($sMachine,1));
}

sub ParseCmdArgs {
  while (@ARGV) {
    $_ = shift @ARGV;
    if ($bDebug) {
      print "dbg: parsing $_\n";
      }
    if (/^[\/\-]/) {				# is arg a switch?
      $arg = substr($_,1,3);			# parse 1st 3 chars:
      $arg =~ s/[A-Z]/[a-z]/;
      if (($arg eq "hel") || (substr($arg,0,1) eq "?")) { &Help(); exit; }
      if (substr($arg,0,1) eq "v") { $bVerbose = 1; }
      if (($arg eq "deb")) { $bDebug = 1; }
      }
    else {					# not a switch
      if (/^[\\]/) {				# single machine (UNC)
        s/\s(.*)//;				# remove whitespace
        s/^\\\\//;				# remove leading \\
        $sMachine = $_;
        $bSingleMachine = 1;
        }
      else { $sMachineList = $_; }
      }
    }
  }