Mega Code Archive
Windows services - starting and stopping
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When installing certain types of programs it maybe necessary to restart related services to avoid conflicts. Regardless of the reason why you need to control services, following functions can help you with starting and stopping services running on the local computer or on a remote machine.
uses WinSvc;
//
// start service
//
// return TRUE if successful
//
// sMachine:
// machine name, ie: \SERVER
// empty = local machine
//
// sService
// service name, ie: Alerter
//
function ServiceStart(
sMachine,
sService : string ) : boolean;
var
//
// service control
// manager handle
schm,
//
// service handle
schs : SC_Handle;
//
// service status
ss : TServiceStatus;
//
// temp char pointer
psTemp : PChar;
//
// check point
dwChkP : DWord;
begin
ss.dwCurrentState := -1;
// connect to the service
// control manager
schm := OpenSCManager(
PChar(sMachine),
Nil,
SC_MANAGER_CONNECT);
// if successful...
if(schm > 0)then
begin
// open a handle to
// the specified service
schs := OpenService(
schm,
PChar(sService),
// we want to
// start the service and
SERVICE_START or
// query service status
SERVICE_QUERY_STATUS);
// if successful...
if(schs > 0)then
begin
psTemp := Nil;
if(StartService(
schs,
0,
psTemp))then
begin
// check status
if(QueryServiceStatus(
schs,
ss))then
begin
while(SERVICE_RUNNING
<> ss.dwCurrentState)do
begin
//
// dwCheckPoint contains a
// value that the service
// increments periodically
// to report its progress
// during a lengthy
// operation.
//
// save current value
//
dwChkP := ss.dwCheckPoint;
//
// wait a bit before
// checking status again
//
// dwWaitHint is the
// estimated amount of time
// the calling program
// should wait before calling
// QueryServiceStatus() again
//
// idle events should be
// handled here...
//
Sleep(ss.dwWaitHint);
if(not QueryServiceStatus(
schs,
ss))then
begin
// couldn't check status
// break from the loop
break;
end;
if(ss.dwCheckPoint <
dwChkP)then
begin
// QueryServiceStatus
// didn't increment
// dwCheckPoint as it
// should have.
// avoid an infinite
// loop by breaking
break;
end;
end;
end;
end;
// close service handle
CloseServiceHandle(schs);
end;
// close service control
// manager handle
CloseServiceHandle(schm);
end;
// return TRUE if
// the service status is running
Result :=
SERVICE_RUNNING =
ss.dwCurrentState;
end;
The procedure to stop a service is similar to starting a service, except for calling "ControlService()" Win32 function instead of "StartService()", checking for SERVICE_STOPPED rather than SERVICE_RUNNING and using appropriate control codes.
//
// stop service
//
// return TRUE if successful
//
// sMachine:
// machine name, ie: \SERVER
// empty = local machine
//
// sService
// service name, ie: Alerter
//
function ServiceStop(
sMachine,
sService : string ) : boolean;
var
//
// service control
// manager handle
schm,
//
// service handle
schs : SC_Handle;
//
// service status
ss : TServiceStatus;
//
// check point
dwChkP : DWord;
begin
// connect to the service
// control manager
schm := OpenSCManager(
PChar(sMachine),
Nil,
SC_MANAGER_CONNECT);
// if successful...
if(schm > 0)then
begin
// open a handle to
// the specified service
schs := OpenService(
schm,
PChar(sService),
// we want to
// stop the service and
SERVICE_STOP or
// query service status
SERVICE_QUERY_STATUS);
// if successful...
if(schs > 0)then
begin
if(ControlService(
schs,
SERVICE_CONTROL_STOP,
ss))then
begin
// check status
if(QueryServiceStatus(
schs,
ss))then
begin
while(SERVICE_STOPPED
<> ss.dwCurrentState)do
begin
//
// dwCheckPoint contains a
// value that the service
// increments periodically
// to report its progress
// during a lengthy
// operation.
//
// save current value
//
dwChkP := ss.dwCheckPoint;
//
// wait a bit before
// checking status again
//
// dwWaitHint is the
// estimated amount of time
// the calling program
// should wait before calling
// QueryServiceStatus() again
//
// idle events should be
// handled here...
//
Sleep(ss.dwWaitHint);
if(not QueryServiceStatus(
schs,
ss))then
begin
// couldn't check status
// break from the loop
break;
end;
if(ss.dwCheckPoint <
dwChkP)then
begin
// QueryServiceStatus
// didn't increment
// dwCheckPoint as it
// should have.
// avoid an infinite
// loop by breaking
break;
end;
end;
end;
end;
// close service handle
CloseServiceHandle(schs);
end;
// close service control
// manager handle
CloseServiceHandle(schm);
end;
// return TRUE if
// the service status is stopped
Result :=
SERVICE_STOPPED =
ss.dwCurrentState;
end;
Example usage:
if( ServiceStart(
'\ComputerName',
'alerter' ) )then
begin
// "alerter" service on \ComputerName
// was started
// take appropriate action here
end;
// stop "alerter" service
// running on the local
// computer
if( ServiceStop(
'',
'alerter' ) )then
begin
end;
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