# Dirname
> [Regular expression][regexp] to capture a path [dirname][dirname].
## Usage
```javascript
var reDirname = require( '@stdlib/regexp/dirname' );
```
#### reDirname( \[platform] )
Returns a [regular expression][regexp] to capture a path [dirname][dirname].
```javascript
var RE = reDirname();
// returns
RE = reDirname( 'posix' );
// returns
var dir = RE.exec( '/foo/bar/index.js' )[ 1 ];
// returns '/foo/bar'
RE = reDirname( 'win32' );
// returns
dir = RE.exec( 'C:\\foo\\bar\\index.js' )[ 1 ];
// returns 'C:\\foo\\bar'
```
#### reBasename.REGEXP
[Regular expression][regexp] to capture a path dirname.
```javascript
var bool = ( reDirname.REGEXP.toString() === reDirname().toString() );
// returns true
```
#### reDirname.REGEXP_POSIX
[Regular expression][@stdlib/regexp/dirname-posix] to capture a [POSIX][posix] path dirname.
```javascript
var dir = reDirname.REGEXP_POSIX.exec( '/foo/bar/index.js' )[ 1 ];
// returns '/foo/bar'
```
#### reDirname.REGEXP_WIN32
[Regular expression][@stdlib/regexp/dirname-windows] to capture a Windows path dirname.
```javascript
var dir = reDirname.REGEXP_WIN32.exec( 'C:\\foo\\bar\\index.js' )[ 1 ];
// returns 'C:\\foo\\bar'
```
## Notes
- The as `REGEXP` exported [regular expression][regexp] is [platform][@stdlib/assert/is-windows]-dependent. If the current process is running on Windows, `REGEXP === REGEXP_WIN32`; otherwise, `REGEXP === REGEXP_POSIX`.
## Examples
```javascript
var reDirname = require( '@stdlib/regexp/dirname' );
var RE_DIRNAME = reDirname();
var dir;
// Assuming a POSIX platform...
dir = RE_DIRNAME.exec( '/foo/bar/index.js' )[ 1 ];
// returns '/foo/bar'
dir = reDirname.REGEXP_POSIX.exec( '/foo/bar/home.html' )[ 1 ];
// returns '/foo/bar'
dir = reDirname.REGEXP_WIN32.exec( 'C:\\foo\\bar\\home.html' )[ 1 ];
// returns 'C:\\foo\\bar'
```
[regexp]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions
[dirname]: https://en.wikipedia.org/wiki/Dirname
[posix]: https://en.wikipedia.org/wiki/POSIX
[@stdlib/assert/is-windows]: https://www.npmjs.com/package/@stdlib/assert-is-windows
[@stdlib/regexp/dirname-posix]: https://www.npmjs.com/package/@stdlib/regexp/tree/main/dirname-posix
[@stdlib/regexp/dirname-windows]: https://www.npmjs.com/package/@stdlib/regexp/tree/main/dirname-windows