Free Linux Foundation Certified System Administrator 2026 Questions and Answers

Question 1

What is the proper command to open the download.bz2 archive file and extract its contents?

Accepted Answer

bunzip2 download.bz2

Answer

Files with the `.bz2` extension are compressed using the bzip2 compression algorithm. The correct command to open and extract the contents of a `download.bz2` archive file is `bunzip2 download.bz2`. This utility is specifically designed to decompress bzip2 archives, typically replacing the compressed file with its uncompressed version.

Question 2

Which of the above commands manages and preloads the keys required for automatic authentication when connecting to other machines over SSH?

Accepted Answer

ssh-agent

Answer

`ssh-agent` is the command that manages and preloads the keys required for automatic authentication when connecting to other machines over SSH. It runs as a background process, holding private keys in memory. Users can add their keys to the agent (using `ssh-add`), and then `ssh-agent` handles the authentication for subsequent SSH connections without requiring the user to re-enter passphrases, enhancing both convenience and security.

Question 3

What is the proper command to open the download.bz2 archive file and extract its contents?

Accepted Answer

bunzip2 download.bz2

Answer

The `.bz2` file extension indicates that the archive was compressed using the `bzip2` compression utility. To decompress such a file and extract its contents, the corresponding `bunzip2` command is used. Other commands like `unzip` are for `.zip` files, and `uncompress` is for `.Z` files.

Question 4

How can the error output of a command be discarded while writing the normal output to a file?

Accepted Answer

command >file 2>/dev/null

Answer

In shell commands, `>` redirects standard output (stdout, file descriptor 1) and `2>` redirects standard error (stderr, file descriptor 2). To write normal output to a file, `>file` is used. To discard error output, `2>/dev/null` redirects stderr to `/dev/null`, which is a special device that effectively discards all data written to it.

Question 5

What command will show the final line of the text file foo.txt?

Accepted Answer

tail -n 1 foo.txt

Answer

The `tail` command is used to display the end portion of a file. By adding the `-n 1` option, you specify that only the last line of the file should be shown. This combination precisely fulfills the requirement of showing only the final line of `foo.txt`.

LFCS Certification Practice Test

LFCS Certification Practice Test

Free Linux Foundation Certified System Administrator 2026 Questions and Answers