Implement --owner and --perms

src/system/file/chown.rs

@@ -0,0 +1,26 @@
+use std::{fs::File, io, os::fd::AsRawFd};
+
+use crate::{
+    cutils::cerr,
+    system::interface::{GroupId, UserId},
+};
+
+mod sealed {
+    use std::fs::File;
+
+    pub(crate) trait Sealed {}
+
+    impl Sealed for File {}
+}
+
+pub(crate) trait Chown: sealed::Sealed {
+    fn chown(&self, uid: UserId, gid: GroupId) -> io::Result<()>;
+}
+
+impl Chown for File {
+    fn chown(&self, owner: UserId, group: GroupId) -> io::Result<()> {
+        let fd = self.as_raw_fd();
+
+        cerr(unsafe { libc::fchown(fd, owner, group) }).map(|_| ())
+    }
+}

src/system/file.rs → src/system/file/lock.rs

@@ -109,3 +109,4 @@ mod tests {
         assert!(f.unlock().is_ok());
     }
 }
+

src/system/file/mod.rs

@@ -0,0 +1,5 @@
+mod chown;
+mod lock;
+
+pub(crate) use lock::Lockable;
+pub(crate) use chown::Chown;