In the command 'll &> file.txt', what does the '&>' redirection do?

• A. Redirects stdout to the file
• B. Redirects stdout to the file descriptor 2
• C. Redirects only stderr to the file
• D. Redirects both stdout and stderr to the file

Answer: (D)

This tests how to merge both output streams into one file. In Bash, there are two default data streams: standard output and standard error. The &> operator redirects both of these streams to the same destination, so ll &> file.txt sends everything normally printed by the command and any error messages into file.txt. It’s effectively like redirecting stdout to the file and then redirecting stderr to the same place stdout is going, which ends up being the file. This is different from redirecting only stdout (which would be a plain > file.txt) or only stderr (which would be 2> file.txt).