# Function rustix::io::fcntl_dupfd_cloexec

source · [−]

    pub fn fcntl_dupfd_cloexec<Fd: AsFd>(fd: Fd, min: RawFd) -> Result<OwnedFd>

Expand description

`fcntl(fd, F_DUPFD_CLOEXEC)`—Creates a new `OwnedFd` instance, with value at least `min`, that has `O_CLOEXEC` set and that shares the same underlying [file description] as `fd`.

POSIX guarantees that `F_DUPFD_CLOEXEC` will use the lowest unused file descriptor which is at least `min`, however it is not safe in general to rely on this, as file descriptors may be unexpectedly allocated on other threads or in libraries.

## References

- POSIX
- Linux