The following code uses Win32::Semaphore to do what you want. 
use strict;
use Win32::Semaphore;
#Determine the programe name, $progname
my $progpath = $0;
my $progname=lc($0);
if($progname=~/[\/\\]/){
    my @stmp=split(/[\/\\]/,$progname);
    $progname=pop(@stmp);
    }
$progpath=~s/\\/\//g;
$progpath=~s/\/$progname$//is;
$progpath=~s/\//\\/g;
$progname=~s/\Q$progpath\E//s;
$progname=~s/^[\\\/]+//s;
if($progname=~/(.+?)\.(exe|pl|so)/is){$progname=$1;}

#Check to see if a semaphore with this program is already open, if so 
+die.
if(Win32::Semaphore->open($progname)){
    print "$progname is already running\n";
    exit;
    }
#Create a semaphore before starting anything else.
my $sObject;
print "creating semaphore $progname\n";
Win32::Semaphore::Create($sObject,1,1,$progname) || die "Die: $!\n";
##############################################################
##########  Program Code goes below here  ####################
##############################################################
while(1){
    #sample pause loop so that the program does not die
    select(undef,undef,undef,.01);
    }
exit;
##############################################################
END {
    if($sObject){$sObject->Release();}
    }

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http://www.basgetti.com
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In reply to Re^2: only allow single instance of program running by slloyd
in thread only allow single instance of program running by water

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