API: Windows Services

Functions for getting status, starting, stopping, and restarting Windows services.

C++ registration: regService(js).

Requires JsN.exe to be run as administrator.

---

Possible service states

State (state)	Code (code)	Description
"running"	4	Service is running
"stopped"	1	Service is stopped
"start_pending"	2	Start in progress
"stop_pending"	3	Stop in progress
"paused"	7	Paused
"pause_pending"	6	Transitioning to pause
"continue_pending"	5	Resuming
"unknown"	—	Unknown state

---

svc_status

svc_status(name: string) → object

Get the current state of a service.

Parameters:

Parameter	Type	Description
name	string	Service system name (not the display name)

Result:

Field	Type	Description
state	string	State from the table above
code	number	Numeric SERVICE_* code (1–7)
pid	number	Service process PID (0 if not running)
error	string	Error message or ""

Example:

let s = svc_status("MyService");

if (s.error) {
    console.log("Error:", s.error);
} else {
    console.log("State:", s.state);  // "running"
    console.log("PID:", s.pid);      // 4321
}

---

svc_start

svc_start(name: string) → object

Start a service.

Parameters:

Parameter	Type	Description
name	string	Service system name

Result:

Field	Type	Description
ok	bool	true — start command sent successfully
error	string	Error message or ""

Example:

let r = svc_start("MyService");
if (r.ok) {
    console.log("Service is starting");
} else {
    console.log("Start error:", r.error);
}

---

svc_stop

svc_stop(name: string) → object

Stop a service.

Parameters:

Parameter	Type	Description
name	string	Service system name

Result:

Field	Type	Description
ok	bool	true — stop command sent successfully
error	string	Error message or ""

Example:

let r = svc_stop("MyService");
if (r.ok) {
    console.log("Service is stopping");
} else {
    console.log("Stop error:", r.error);
}

---

svc_restart

svc_restart(name: string) → object

Restart a service: stop → wait for completion (up to 15 sec) → start.

Parameters:

Parameter	Type	Description
name	string	Service system name

Result:

Field	Type	Description
ok	bool	true — service restarted successfully
error	string	Error message or ""

Example:

let r = svc_restart("MyService");
if (r.ok) {
    console.log("Service restarted");
} else {
    console.log("Restart error:", r.error);
}

---

Full example: state check and auto-restart

let svcName = "MyService";

// Check state
let s = svc_status(svcName);

if (s.error) {
    console.log("[ERROR] Failed to get status:", s.error);
} else if (s.state === "stopped") {
    console.log("[WARN] Service is stopped, starting...");
    let r = svc_start(svcName);
    console.log("Result:", r.ok ? "OK" : r.error);

} else if (s.state === "running") {
    console.log("[OK] Service is running, PID:", s.pid);

    // Check if the process is responding
    let alive = proc_alive(s.pid);
    if (!alive.responding) {
        console.log("[WARN] Process is hung, restarting service...");
        let r = svc_restart(svcName);
        console.log("Restart:", r.ok ? "OK" : r.error);
    }

} else {
    console.log("[INFO] State:", s.state);
}

---

How to find the service system name

The system name (not the display name) can be found:

1. PowerShell: Get-Service | Where-Object { $_.DisplayName -like "*MyApp*" } | Select-Object Name
2. Task Manager: Services tab → Name column
3. services.msc: right-click → Properties → Service name field