dup2 (nr 33)

Linux Signature

int dup2(int oldfd, int newfd);

Description

Duplicates file descriptor oldfd to newfd. If newfd is already open, it is silently closed first.

Current Implementation

1. If oldfd == newfd: validates that oldfd is open, returns newfd.
2. Reads the FdEntry (handle + flags) from oldfd.
3. Clones the Arc<dyn FileHandle> and installs it at newfd.
4. The new fd does not inherit FD_CLOEXEC from the old fd (per POSIX).
5. If newfd was previously open, its old handle is dropped (refcount decremented).
6. The fd table is extended if newfd exceeds the current length.

Source: osl/src/syscalls/fs.rs — sys_dup2

Errors