# libtmux:field-value

- **Package:** libtmux
- **Language:** Common Lisp
- **Kind:** function
- **Source:** https://github.com/libtmux/libtmux-lisp/blob/c2e5fc4ed3befda21f45dfa5d5868c38fd138311/src/model.lisp#L33
- **Public owner:** libtmux
- **Page:** https://libtmux.org/en/lisp/latest/reference/libtmux-field-value/

```
(field-value entity field)

Primary method: libtmux:entity, common-lisp:t:
(field-value (entity libtmux:entity) (field common-lisp:t))
```

Return a captured field and presence as two values, without I/O.
Present false is NIL,T; absence is NIL,NIL. Strings and relation containers are
copied. Unknown fields and unloaded relations signal FIELD-UNAVAILABLE.

## Methods

### `(field-value (entity libtmux:entity) (field common-lisp:t))`

## Parameters

- `entity` (for `field-value(entity, field)`)
- `field` (for `field-value(entity, field)`)
- `entity` (`libtmux:entity`) (for `Primary method: libtmux:entity, common-lisp:t`)
- `field` (`common-lisp:t`) (for `Primary method: libtmux:entity, common-lisp:t`)

## Guides

Pages that discuss `field-value`.

- [Captures and identity](/en/lisp/latest/concepts/captures/)