forked from lix-project/lix-website
55 lines
1.3 KiB
Markdown
55 lines
1.3 KiB
Markdown
|
# 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
|
||
|
|
var which = require('which')
|
||
|
|
|
||
|
|
// async usage
|
||
|
|
which('node', function (er, resolvedPath) {
|
||
|
|
// er is returned if no "node" is found on the PATH
|
||
|
|
// if it is found, then the absolute path to the exec is returned
|
||
|
|
})
|
||
|
|
|
||
|
|
// or promise
|
||
|
|
which('node').then(resolvedPath => { ... }).catch(er => { ... not found ... })
|
||
|
|
|
||
|
|
// sync usage
|
||
|
|
// throws if not found
|
||
|
|
var resolved = which.sync('node')
|
||
|
|
|
||
|
|
// if nothrow option is used, returns null if not found
|
||
|
|
resolved = which.sync('node', {nothrow: true})
|
||
|
|
|
||
|
|
// Pass options to override the PATH and PATHEXT environment vars.
|
||
|
|
which('node', { path: someOtherPath }, function (er, resolved) {
|
||
|
|
if (er)
|
||
|
|
throw er
|
||
|
|
console.log('found at %j', resolved)
|
||
|
|
})
|
||
|
|
```
|
||
|
|
|
||
|
|
## CLI USAGE
|
||
|
|
|
||
|
|
Same as the BSD `which(1)` binary.
|
||
|
|
|
||
|
|
```
|
||
|
|
usage: which [-as] program ...
|
||
|
|
```
|
||
|
|
|
||
|
|
## 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.
|