cmdinstance:=exec.Command("powershell.exe","-WindowStyle","Hidden","-Command","New-NetFirewallRule","-DisplayName","'Go Web Server'","-Direction","Inbound",file,"-Action","Allow")
//Create firewall rule if no firewall rule exists.
cmdinstance:=exec.Command("powershell.exe","-WindowStyle","Hidden","-Command","$r","=","Get-NetFirewallRule","-DisplayName","'Go Web Server'","2>","$null;","if","($r)","{write-host 'found rule';}","else","{New-NetFirewallRule","-DisplayName","'Go Web Server'","-Direction","Inbound",file,"-Action","Allow}")
cmdinstance.SysProcAttr=&syscall.SysProcAttr{HideWindow:true}// Make it silent.