Linux+ Bash Scripting and Automation Questions and Answers

Question 1

A script has a variable defined as `FILENAME="report_final.docx"`. Which parameter expansion command will correctly remove the file extension, resulting in `report_final`?

Accepted Answer

echo "${FILENAME%.*}"

Answer

The `${variable%.*}` syntax is a standard parameter expansion that removes the shortest matching suffix pattern. In this case, `.*` matches the last dot and any characters that follow, effectively stripping the file extension. `${%%.*}` would remove the longest match, which is useful for files with multiple dots (e.g., `archive.tar.gz`), and `${#*.}` removes a prefix, not a suffix.

Question 2

A system administrator wants a script to create a tar archive with the current date in `YYYY-MM-DD` format included in the filename. Which of the following commands correctly creates an archive named `archive-2026-03-18.tar.gz` (assuming the current date is March 18, 2026)?

Accepted Answer

tar -czf archive-$(date +%F).tar.gz /var/log/

Answer

The `$(...)` syntax is the modern and preferred method for command substitution. It executes the command within the parentheses (`date +%F`) and substitutes its standard output into the command line. The `+%F` format specifier for the `date` command is a shorthand for `%Y-%m-%d`, producing the required date format.

Question 3

A developer needs a script to process all PNG images in the current directory. Which of the following Bash `for` loops correctly iterates through all files ending with a `.png` extension?

Accepted Answer

for i in *.png; do echo "Found $i"; done

Answer

The most robust and standard way to iterate over files is to use file globbing directly in the `for` loop statement (`for i in *.png`). The shell expands the `*.png` glob into a list of matching filenames, handling spaces and special characters correctly. Using command substitution with `ls` (`$(ls *.png)`) is discouraged as it can lead to issues with filenames containing whitespace.

Question 4

An automation script needs to check if the directory `/srv/backups` exists before attempting to write a file to it. Which conditional statement correctly performs this check?

Accepted Answer

if [ -d "/srv/backups" ]; then echo "Exists"; fi

Answer

The `test` command, often written with square brackets `[ ]`, uses file test operators to check file attributes. The `-d` operator specifically tests if the given path exists and is a directory. The `-f` operator checks for a regular file, and `-e` checks for general existence (file, directory, socket, etc.).

Question 5

A system administrator needs to schedule a maintenance script at `/opt/scripts/sync.sh` to run at 1:15 AM every Monday. Which of the following `crontab` entries is correct?

Accepted Answer

15 1 * * 1 /opt/scripts/sync.sh

Answer

The crontab format is `minute hour day-of-month month day-of-week command`. The values `15 1 * * 1` correctly specify the 15th minute of the 1st hour, on any day of the month and any month, but only on the 1st day of the week. In cron, both 1 and 'mon' represent Monday.

Linux Practice Test

Linux Practice Test

Linux+ Bash Scripting and Automation Questions and Answers