# CMSG_SPACE

- **Language:** C
- **Kind:** constant
- **Source:** https://github.com/tmux/tmux/blob/e476c1230b958df0cb12977517d24b3dc931375b/compat.h#L206
- **Page:** https://libtmux.org/en/tmux/latest/reference/c-define-compat-h-cmsg_space/

```c
#define CMSG_SPACE(len) (CMSG_ALIGN(sizeof(struct cmsghdr)) + CMSG_ALIGN(len))
```

## Referenced declarations

- [`CMSG_ALIGN`](/en/tmux/latest/reference/c-define-compat-h-cmsg_align/) (constant)