If you want to create a file in a directory, which permissions must you have?

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

Answer: (B)

To create a file in a directory, you must be able to modify the directory’s listing of entries and access the path. Write permission on the directory lets you add new entries (files) or remove them, while execute permission lets you traverse into the directory and access its contents. Without execute, you can’t reach the directory to create something inside it, and without write, you can’t add a new entry. Read permission isn’t required to create files and isn’t enough on its own because it doesn’t allow modification. So the necessary combination is write and execute on the directory.