https://github.com/npm/node-which
Like which(1) unix command. Find the first instance of an executable in the PATH.
https://github.com/npm/node-which
npm-cli
Last synced: 5 days ago
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Like which(1) unix command. Find the first instance of an executable in the PATH.
- Host: GitHub
- URL: https://github.com/npm/node-which
- Owner: npm
- License: isc
- Created: 2011-08-07T18:28:30.000Z (over 13 years ago)
- Default Branch: main
- Last Pushed: 2025-04-09T14:29:42.000Z (5 days ago)
- Last Synced: 2025-04-09T19:16:07.961Z (5 days ago)
- Topics: npm-cli
- Language: JavaScript
- Homepage:
- Size: 188 KB
- Stars: 335
- Watchers: 26
- Forks: 48
- Open Issues: 4
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- Contributing: CONTRIBUTING.md
- License: LICENSE
- Code of conduct: CODE_OF_CONDUCT.md
- Codeowners: .github/CODEOWNERS
- Security: SECURITY.md
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README
# which
Like the unix `which` utility.
Finds the first instance of a specified executable in the PATH
environment variable. Does not cache the results, so `hash -r` is not
needed when the PATH changes.
## USAGE
```javascript
const which = require('which')
// async usage
// rejects if not found
const resolved = await which('node')
// if nothrow option is used, returns null if not found
const resolvedOrNull = await which('node', { nothrow: true })
// sync usage
// throws if not found
const resolved = which.sync('node')
// if nothrow option is used, returns null if not found
const resolvedOrNull = which.sync('node', { nothrow: true })
// Pass options to override the PATH and PATHEXT environment vars.
await which('node', { path: someOtherPath, pathExt: somePathExt })
```
## CLI USAGE
Just like the BSD `which(1)` binary but using `node-which`.
```
usage: node-which [-as] program ...
```
You can learn more about why the binary is `node-which` and not `which`
[here](https://github.com/npm/node-which/pull/67)
## OPTIONS
You may pass an options object as the second argument.
- `path`: Use instead of the `PATH` environment variable.
- `pathExt`: Use instead of the `PATHEXT` environment variable.
- `all`: Return all matches, instead of just the first one. Note that
this means the function returns an array of strings instead of a
single string.