ServiceManager
From Lazarus wiki
Revision as of 09:07, 30 April 2013 by Jwdietrich (talk | contribs)
For Windows, the fcl-extra package contains a unit called ServiceManager.
Example that checks whether the SamSs (Security Accounts Manager; should always be running) service is running is below. (Command line equivalent sc query samss).
program ServiceTest;
// Check if a certain process is running.
{$mode objfpc}{$H+}
uses
Classes,
SysUtils,
ServiceManager,
JwaWinSvc {for services declarations};
function IsServiceRunning(ServiceName: string): boolean;
{description Checks if a Windows service is running}
var
Services: TServiceManager;
ServiceStatus: TServiceStatus;
begin
//Check for existing services
//equivalent to sc query <servicename>
Services := TServiceManager.Create(nil);
try
try
Services.Acces := SC_MANAGER_CONNECT; //Note typo in property.
//We don't need more access permissions than this; by default
//the servicemanager is trying to get all access
Services.Connect; //Now connect with requested access level
Services.GetServiceStatus(ServiceName, ServiceStatus);
if ServiceStatus.dwCurrentState = SERVICE_RUNNING then
begin
Result := True;
end
else
begin
Result := False;
end;
Services.Disconnect;
except
on E: EServiceManager do
begin
// A missing service might throw a missing handle exception? No?
{LogOutput('Error getting service information for ' + ServiceName +
'. Technical details: ' + E.ClassName + '/' + E.Message);}
Result := False;
raise; //rethrow original exception
end;
on E: Exception do
begin
{LogOutput('Error getting service information for ' + ServiceName +
'. Technical details: ' + E.ClassName + '/' + E.Message);
}
Result := False;
raise; //rethrow original exception
end;
end;
finally
Services.Free;
end;
end;
const
ServiceToTest = 'SamSs';
//Security Accounts Manager, should be running, at least on Vista
begin
WriteLn('Starting test for ' + ServiceToTest + ' service.');
if IsServiceRunning(ServiceToTest) then
begin
WriteLn('The ' + ServiceToTest + ' service is running');
end
else
begin
WriteLn('The ' + ServiceToTest + ' service is not running');
end;
end.