# getrusage.js
[](https://www.npmjs.com/package/getrusage.js)
POSIX system function [`getrusage()`](https://www.gnu.org/software/libc/manual/html_node/Resource-Usage.html) is usually used to examine the resource usage of a process.
[`getrusage.js`](https://www.npmjs.com/package/getrusage.js) is a binding to Node.js via [Node-API](https://nodejs.org/api/n-api.html), and makes pre-build binaries for distribution, with **0 other dependencies!**
You don't need to compile (`node-gyp`) or download (`node-pre-gyp`) anything by postinstall.
## Support platforms
| Platform \ Nodejs | node 12 | node 14 | node 16 | node 18 |
| -------------------------------------------------- | ------- | ------- | ------- | ------- |
| **Linux x64**
*(gcc >= 4.9)* | ✓ | ✓ | ✓ | ✓ |
| **Linux arm64**
*(gcc >= 5.1)* | ✓ | ✓ | ✓ | ✓ |
| **Linux arm32**
*(gcc >= 5.1)* | ✓ | ✓ | ✓ | ✓ |
| **macOS x64** | ✓ | ✓ | ✓ | ✓ |
| **macOS arm64**
*(M1/M2 chips)* | ✓ | ✓ | ✓ | ✓ |
> Windows? not support yet, due to `getrusage()` is POSIX only.
## Install
```bash
npm i getrusage.js
```
## Usage
```ts
import {
getrusage,
RUSAGE_SELF,
RUSAGE_CHILDREN,
} from 'getrusage.js'
import type { RUsage } from 'getrusage.js'
/**
* `getrusage()` is equivalent to `getrusage(RUSAGE_SELF)`
* `getrusage(RUSAGE_CHILDREN)` means usage of "All child processes (direct and indirect) that have already terminated"
*/
const usage: RUsage = getrusage()
console.log(usage)
// {
// utime: 0.513607,
// stime: 0.011146,
// maxrss: 65421,
// idrss: 0,
// ixrss: 0,
// isrss: 0,
// minflt: 9753,
// majflt: 12,
// nswap: 0,
// inblock: 0,
// oublock: 0,
// msgsnd: 0,
// msgrcv: 0,
// nsignals: 0,
// nvcsw: 1347,
// nivcsw: 10
// }
```
interface of `RUsage` and explain fields see:
```ts
/**
* Resource Usage data struct
* https://www.gnu.org/software/libc/manual/html_node/Resource-Usage.html#index-struct-rusage
*/
interface RUsage {
/**
* time spent in executing user instructions (seconds)
* sum of tv_sec and tv_usec (unit: seconds)
*/
utime: number;
/**
* time spent in operating system code on behalf of processes (seconds)
* sum of tv_sec and tv_usec (unit: seconds)
*/
stime: number;
/**
* the maximum of physical memory that processes used simultaneously (kilobytes)
* always normalized unit in kilobytes on macOS
*/
maxrss: number;
/** deprecated fields in gnu: idrss / ixrss / isrss */
idrss: number;
ixrss: number;
isrss: number;
/** the number of page faults which were serviced without requiring any I/O (count) */
minflt: number;
/** the number of page faults which were serviced by doing I/O (count) */
majflt: number;
nswap: number;
inblock: number;
oublock: number;
/** number of IPC messages sent (count) */
msgsnd: number;
/** number of IPC messages received (count) */
msgrcv: number;
/** number of signals received (count) */
nsignals: number;
/**
* the number of times processes voluntarily invoked a context switch (count)
* (usually to wait for some service)
*/
nvcsw: number;
/**
* the number of times an involuntary context switch took place (count)
* because a time slice expired, or another process of higher priority was scheduled
*/
nivcsw: number;
}
```
## License
MIT