# Extra Clang Tools 21.1.6 documentation

## clang-tidy - android-cloexec-dup

# android-cloexec-dup

The usage of `dup()` is not recommended, it’s better to use `fcntl()`, which can set the close-on-exec flag. Otherwise, an opened sensitive file would remain open across a fork+exec to a lower-privileged SELinux domain.

Examples:

    int fd = dup(oldfd);

    // becomes

    int fd = fcntl(oldfd, F_DUPFD_CLOEXEC);