When renaming a file, what permissions are required?

• A. Read and write for the file
• B. Write and execute for the directory
• C. Execute only for the directory
• D. Read for the directory

Answer: (B)

Renaming a file changes the directory entry, not the file’s contents. That means the permission that matters is on the directory that contains the file, because you’re updating the directory’s listing.

The best answer is the one that requires both write and execute permissions on the directory. Write permission lets you modify the directory’s entries, and execute permission lets you access and traverse the directory to perform that modification. Without execute, you can’t access or rename entries; without write, you can’t change the directory’s contents.

Permissions on the file itself aren’t what governs renaming, since the operation doesn’t edit the file itself. Only the directory’s permissions control the ability to rename. The other options fail because read on the file, or execute-only, or read on the directory don’t provide the necessary capability to alter the directory’s entries.