010-160 The Power OF The Command Line Practice Test 2 — 15 Questions

Question 1

You are reviewing file permissions and want to identify which of the following statements about the `chmod` command are true. (Choose two.)

Accepted Answer

`chmod u+x script.sh` adds execute permission for the file's owner.. The two true statements are that u+x adds execute for the owner, and that 644 sets read/write for owner and read for group and others. The other options describe operations incorrectly, such as claiming a-w affects only group and others, that 755 includes group write, or that g+s sets the sticky bit.

Answer

`chmod a-w file.txt` removes write permission from all users, including the owner.

Answer

`chmod g+s directory` sets the setgid bit, causing new files to inherit the directory's group.

Answer

`chmod 755` gives the owner read, write, and execute, while group and others get read and execute.

Question 2

A user is editing a configuration file with vim and wants to save the changes and exit the editor immediately. Which command should they type in vim's command mode?

Accepted Answer

:wq. To save modifications and leave vim in one action, the user must write the buffer and then quit. The :wq command performs both operations sequentially, ensuring the file on disk reflects the edits before the editor closes. Other commands either discard changes, reload the file, or conditionally save, so they do not satisfy the explicit save-and-exit requirement.

Answer

:e!

Answer

:q!

Answer

:x

Question 3

A system administrator needs to extract a specific file named 'config.yml' from a tarball 'app.tar.gz' without extracting the entire archive. Which command should be used?

Accepted Answer

tar -xzf app.tar.gz config.yml. To extract a single file from a compressed tarball, use tar with the -x (extract), -z (gzip), and -f (file) options, followed by the archive name and the specific file to extract. This avoids unpacking the entire archive. The other options either list contents, exclude the file, or create a new archive.

Answer

tar -tzf app.tar.gz config.yml

Answer

tar -czf app.tar.gz config.yml

Answer

tar -xzf app.tar.gz --exclude=config.yml

Question 4

You are troubleshooting a user's account and want to view the contents of the environment variable HOME without launching a subshell or external program. Which command displays its value?

Accepted Answer

echo $HOME. Shell variable expansion happens before command execution, so prefixing a variable name with a dollar sign inside a command line substitutes its stored value. Using the echo builtin then writes that substituted string to standard output. This works for any environment variable inherited by the shell, requires no external binary, and produces output immediately visible on the terminal.

Answer

env HOME

Answer

cat $HOME

Answer

printenv HOME > /dev/null

Question 5

A user wants to find all files under /home that are larger than 10 MB and were modified more than 30 days ago, then delete them. Which command sequence is correct?

Accepted Answer

find /home -type f -size +10M -mtime +30 -exec rm {} \;. The find command with -exec rm {} \; is the classic method to delete files matching criteria. Piping to xargs is fragile with special characters, -delete is valid but not the expected sequence, and rm -rf adds unnecessary risk. The correct answer uses find's built-in execution to delete each file individually.

Answer

find /home -type f -size +10M -mtime +30 -exec rm -rf {} +

Answer

find /home -type f -size +10M -mtime +30 -delete

Answer

find /home -type f -size +10M -mtime +30 | xargs rm

Question 6

A developer wants to run a script named `deploy.sh` in the background, keep it running after logging out, and ensure it continues even if the terminal is closed. Which command sequence is most appropriate?

Accepted Answer

nohup ./deploy.sh &. nohup ./deploy.sh & is the standard way to run a command immune to hangup signals in the background. It ensures the process continues after logout and terminal closure, and it redirects output to nohup.out to avoid terminal I/O errors. The other options either lack output handling or introduce unnecessary complexity.

Answer

./deploy.sh & disown

Answer

setsid ./deploy.sh &

Answer

screen -dmS deploy ./deploy.sh

Question 7

You are writing a shell script and need to capture the standard output of a command into a variable, while also ensuring that any error messages are displayed on the terminal. Which TWO of the following approaches achieve this? (Choose two.)

Accepted Answer

output=`command`. Both $(command) and `command` capture standard output while leaving standard error connected to the terminal. The other options either merge error into output, discard output, or discard error, failing the scenario.

Answer

output=$(command) > /dev/null

Answer

output=$(command 2>&1)

Answer

output=$(command 2>/dev/null)

Question 8

A Linux administrator needs to identify the absolute pathname of the executable that would run if the user types the command 'grep' at the shell prompt. The administrator also wants to know the file type of that executable. Which TWO commands will provide this information? (Choose two.)

Accepted Answer

file $(which grep). To find the absolute pathname of the executable that the shell would run, the which command checks the PATH and returns the first match. To determine the file type of that executable, the file command inspects the file's content and reports its format. Combining these two commands with command substitution yields both pieces of information, while other commands like type, ls -l, and whereis do not fully satisfy the dual requirement.

Answer

whereis grep

Answer

type grep

Answer

ls -l $(which grep)

Question 9

A system administrator needs to monitor a growing log file in real time and also filter the output to show only lines containing the word 'ERROR'. Which TWO commands or command combinations achieve this? (Choose two.)

Accepted Answer

tail -f /var/log/app.log | grep ERROR. The correct approaches both use tail -f to follow the file and grep to filter for ERROR. The --line-buffered option in one ensures immediate output, while the other relies on grep's default behavior which often works for pipes. The other options either re-read the whole file periodically, misuse interactive tools in a pipe, or do not follow the file at all.

Answer

cat /var/log/app.log | grep ERROR | tail -f

Answer

less +F /var/log/app.log | grep ERROR

Answer

watch -n 1 'grep ERROR /var/log/app.log'

Question 10

A user wants to find all files in the /etc directory that have been modified in the last 24 hours and are larger than 1 MB. Which TWO commands will accomplish this? (Choose two.)

Accepted Answer

find /etc -type f -mmin -1440 -size +1M. The find command can combine multiple tests. To match files modified within the last 24 hours, either -mtime -1 or -mmin -1440 works. To match files larger than 1 MB, -size +1M is needed. The two correct commands use these conditions together, while the others either misinterpret the time range or use an incorrect size value.

Answer

find /etc -type f -mtime -1 -size 1M

Answer

find /etc -type f -mtime 1 -size +1M

Answer

find /etc -type f -mtime -1 -size +1k

Question 11

You want to find all occurrences of the string 'ERROR' within the 'syslog' file. Which command is most appropriate?

Accepted Answer

grep 'ERROR' syslog. 'grep' (global regular expression print) searches a file or input stream for lines matching a pattern and prints them. Running 'grep ERROR syslog' scans the syslog file and outputs every line containing 'ERROR', which is exactly the task described.

Answer

cat 'ERROR' syslog

Answer

find 'ERROR' syslog

Answer

sed 'ERROR' syslog

Question 12

Which command is used to display the current working directory in the terminal?

Accepted Answer

pwd. The `pwd` command stands for 'print working directory' and is specifically designed to output the absolute path of the current directory in a Linux/Unix terminal. It reads the current directory from the kernel and displays it, making it the correct choice for this task. This is a fundamental command in the Linux Essentials (010-160) exam domain.

Answer

dir

Answer

cd

Answer

ls

Question 13

You need to display the contents of a file named 'config.txt' directly to your terminal screen. Which command should you use?

Accepted Answer

cat config.txt. The `cat` command (concatenate) reads one or more files and writes their contents to standard output, which by default is the terminal. Running `cat config.txt` therefore prints the entire file to the screen in one pass, exactly matching the requirement to display file contents directly. It is the canonical tool for this purpose on Linux.

Answer

head config.txt

Answer

echo config.txt

Answer

grep config.txt

Question 14

You wish to send the output of the 'ls -l' command directly into a file named 'dirlist.txt', overwriting any existing content. Which operator should you use?

Accepted Answer

ls -l > dirlist.txt. The single greater-than operator (>) redirects standard output to a file, creating the file if it does not exist or truncating and overwriting it if it does. Therefore 'ls -l > dirlist.txt' writes the directory listing into dirlist.txt, replacing any prior content. This is the standard POSIX shell redirection for overwrite semantics.

Answer

ls -l | dirlist.txt

Answer

ls -l >> dirlist.txt

Answer

ls -l < dirlist.txt

Question 15

You want to replace every occurrence of 'old' with 'new' in the file 'data.txt' and view the result in the terminal. Which command achieves this?

Accepted Answer

sed 's/old/new/g' data.txt. The sed command with the 's/old/new/g' expression performs a global substitution, replacing every occurrence of 'old' with 'new' on each line of data.txt. By default, sed writes the modified content to standard output, which displays the result in the terminal without altering the original file. The 'g' flag is essential because without it, only the first occurrence per line would be replaced.

Answer

sed 's/old/new/' data.txt

Answer

grep 's/old/new/g' data.txt

Answer

sed 'r/old/new/g' data.txt