This isnt really a complete program per se - I just placed it here so I wont lose it again.
-Sx-

#............................................................................
sub verifySessionID {
        my($encryptBIT, $profsID, $realFN, $realLN, $prjSec, $prjComment) = '';
        chdir($Sessions) or &ioError("vsID Directory, CD");

        my($xMatched) = 0;

        # What Sessions are currently active?
        opendir TARGETDIR, "." or &ioError("vsID Directory, Read");
        my(@allfiles) = grep !/^\./, readdir TARGETDIR;
        closedir TARGETDIR;

        if (!@allfiles && !$xAuthenticated) {
            $ercType = "FATAL:";
            $buffer = "Security Violation Detected... " . remote_addr();
            $ercCode = "<P><H2>Session ID Missing -- Do not try to break-in!</H2>";
            $fccjPointer->delete('flipBit');
            &errorReturned($ercType, $buffer, $ercCode);
        }

        if ($xAuthenticated) {
            my($newSessionID)  = '';

            # One Session ID File per Remote Addr and UserID, 
            # if there is a dup, previous Session is destroyed...
            # This is our first time thru this Script...
            $xMatched = 1;  # We matched; because this is a new user...
            $newSessionID = remote_addr() . ".FCCJ." . $usrID;
            open (sessionHandle, "+>$newSessionID") or &ioError("vsID \(1\) File Create"); 

# Create a NEW file, over-writing the OLD one...
            print sessionHandle (remote_addr() . "\|$usrID\|$flipBit\n");
            close (sessionHandle);
            print "<strong><font size=+1>&nbsp;Done!</font></strong>";
            return;
        } elsif (@allfiles) {

            my($newSesID)  = '.';
            my($x) = -1;

            for (@allfiles) {

                $x++; # Let us start at 0, then increment...
                # Now, we will need to read the file contents...
                open (sHandle, $allfiles[$x]) or &ioError("vsID \(1\) File Read");

                while ($newSesID = <sHandle>) {
                    chomp($newSesID); # Get rid of CR at end-of-line...
                    my($remoteAddr, $remoteUsrID, $remoteSessionID) = split(/\|/, $newSesID);

                    if (remote_addr() eq $remoteAddr) {
                        $xMatched = 1;  # We matched the User's IP Addr...

# Split up the SecID Stream...
                        return if ($remoteSessionID eq "FCCJ");  

# Obviously the PrjSec FLAG Changed...
                        my($removeRemoteSecID) =  substr($remoteSessionID, (rindex($remoteSessionID,"FCCJ")));                        
                        my($getRemoteLife)     =  substr($remoteSessionID, (rindex($remoteSessionID, "FCCJ") + length("FCCJ".$yday)));
                        my($getRemoteSecID)    =  substr($remoteSessionID, 0, (length($remoteSessionID) - length($removeRemoteSecID)));
                        
# verify UserSecID...
                        my($usrExists) = '';
                        my($usrFile) = $Users . "/user.dat";
                        
                        # First make sure User ID does already exist!
                        open (vsIDhandle, $usrFile) or &ioError("vsID \(2\) File Read");

                        while ($usrExists = <vsIDhandle>) {
                            chomp($usrExists); # Get rid of CR at end-of-line...
                            ($encryptBIT, $profsID, $realFN, $realLN, $prjSec, $prjComment) = split(/\|/, $usrExists);
                            last if ($getRemoteSecID eq $encryptBIT);
                        }
                        close (vsIDhandle);

                        if ($getRemoteSecID ne $encryptBIT) {
                            $ercType = "FATAL:";
                            $buffer = "Security Violation Detected... " . remote_addr();
                            $ercCode = "<P><H2>Invalid Project User ID --  Do not try to break-in!</H2>";
                            $fccjPointer->delete('flipBit');
                            &errorReturned($ercType, $buffer, $ercCode);
                        } elsif (((($hour * 60 * 60) + ($min * 60) + $sec) -  $getRemoteLife) > $keepAlive) {
                            $ercType = "Error:";
                            $buffer = "<P><H3>Session Idle Too Long;  You Must Log-in Again... " . remote_addr();
                            $ercCode = "</H3><P>NOTICE: <A HREF=\"http://astro.fccj.cc.fl.us/cgi/HrMaintenance.cgi\" 
                                                                    onMouseOver=\"window.status='Click here to Sign Back into 
                                                                   Project...'; return true\">Click Here to Log Back In</A>&nbsp";
                            $fccjPointer->delete('flipBit');
                            &errorReturned($ercType, $buffer, $ercCode);
                        } else {
                        
                            if (defined($prjSec) && (index($displayOnly,  $prjSec) > -1)) { # Who does not have access?
                                $flipBit = "FCCJ";
                                return($flipBit);  

# Turn off security checking and return what was found...
                            }
                            
                            $level = $prjSec; # Otherwise, return the Security Level...

                            # OK, update the Session ID Bit; 
                            # if there is a dup, previous Session is destroyed...
                            # Session ID Bits are unique based up IP Addr and User PROFS ID...
                            $xMatched = 1;  # We matched; we want the Session ID to renew...
                            my($lifeSpan) = ($hour * 60 * 60) + ($min * 60) + $sec;
                            $flipBit = $getRemoteSecID."FCCJ".$yday.$lifeSpan;  # Set the M/F ID Bit with the HH:MM:SS + (Julian Date)...
                            $newSesID = remote_addr() . ".FCCJ." . $profsID;
                            open (xHandle, "+>$newSesID") or  &ioError("vsID \(2\) File Create"); # Create a NEW file, over-writing the OLD one...
                            print xHandle (remote_addr() . "\|$profsID\|$flipBit\n");
                            close (xHandle);
                            return;
                        }

                    } # End of IF
                } # End of WHILE

                last if $xMatched;
            } # End of FOR
        } # End of ELSIF

        if (!$xMatched) {
            $ercType = "FATAL:"; 
            $buffer = "<P>Security Violation Detected... " . remote_addr();
            $ercCode = "<P><H2>Do not try to break-in! &nbsp;Program Stopped...</H2>";
            &errorReturned($ercType, $buffer, $ercCode);
        }
}