#!/usr/bin/perl

use IPC::SysV qw(IPC_STAT IPC_PRIVATE IPC_CREAT IPC_EXCL S_IRUSR S_IWUSR IPC_RMID);

$key=shmget(IPC_PRIVATE,100,IPC_CREAT | IPC_EXCL | S_IRUSR | S_IWUSR);

my $ret=fork();

if($ret>0){
        my $int=0;
        while(1){
                ++$int;
                shmwrite($key,$int,0,99);
                sleep 60;
        }
} else {
        my $t=0;
        while(1){
                shmread($key,$message,0,99);
                ++$t;
                $result=$t-$message;
                print "$t - $message is $result\n";
                sleep 10;
        }
}