# lookpath

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To check if the command exists and where the executable file is.

```js
const { lookpath } = require('lookpath');

const p = await lookpath('bash');
// "/bin/bash", otherwise "undefined"
```

# Install

```
npm install lookpath
```

# Background

- I **DON'T** want to spawn `child_process` **JUST** in order to kick `which`, `where`, `whereis`, or `command -v`.
    - [node.js - Node - check existence of command in path - Stack Overflow](https://stackoverflow.com/questions/34953168/node-check-existence-of-command-in-path/)
    - [Node.js: Check if a command exists - Gist](https://gist.github.com/jmptable/7a3aa580efffdef50fa9f0dd3d068d6f)
    - [mathisonian/command-exists: node module to check if a command-line command exists - GitHub](https://github.com/mathisonian/command-exists)
- then I checked Go implementation of [`exec.LookPath`](https://golang.org/pkg/os/exec/#LookPath).
    - [src/os/exec/lp_unix.go - The Go Programming Language](https://golang.org/src/os/exec/lp_unix.go?s=928:970#L24)
- so I concluded that scanning under `$PATH` or `$Path` is the best straightforward way to check if the command exists.

# Options

```js
const { lookpath } = require('lookpath');

const p = await lookpath('bash', { include: ['/home/hiromu/.bin'], exclude: ['/mnt'] });
// include: Do scan also under `~/.bin`
// exclude: Do not scan under `/mnt`
```

# Issues

- https://github.com/otiai10/lookpath/issues

Any feedback would be appreciated ;)