LPIC-1 Shells, Scripting and Data Management Practice Test 3 — 15 Questions

Question 1

A user wants every new interactive Bash shell to set EDITOR=vim and add /opt/tools/bin to PATH, but does not want these changes to affect non-interactive scripts run by cron. Which file should the user modify to achieve this?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

~/.bashrc. Interactive non-login shells read ~/.bashrc, which is the only file here that targets every new interactive terminal session for a single user without touching cron. ~/.bash_profile covers login shells only, while /etc/profile and /etc/bash.bashrc are system-wide and affect other users and login contexts, so they do not satisfy the user-scoped, interactive-only requirement.

Answer

/etc/profile

Answer

~/.bash_profile

Answer

/etc/bash.bashrc

Question 2

A junior administrator needs to write a Bash script that processes a list of filenames stored in a file called `list.txt`, one per line. The filenames may contain spaces, tabs, and special characters. Which TWO of the following constructs are appropriate for reading and iterating over these filenames safely? (Choose two.)

Accepted Answer

while IFS= read -r filename; do ...; done < list.txt. The safe methods use read with IFS= and -r to preserve whitespace and backslashes, and avoid word splitting. Redirection or process substitution feeds the file directly to the loop. The other constructs suffer from word splitting, glob expansion, or subshell issues, making them unsuitable for filenames with spaces or special characters.

Answer

for filename in `cat list.txt`; do ...; done

Answer

for filename in $(cat list.txt); do ...; done

Answer

cat list.txt | while read filename; do ...; done

Question 3

A shell script processes a list of filenames stored in a variable. Some filenames contain spaces and special characters. Which TWO techniques ensure that each filename is handled as a single argument when passed to a command? (Choose two.)

Accepted Answer

Use an array and expand with "${array[@]}". The safe ways to handle filenames with spaces and special characters are to use bash arrays with "${array[@]}" or to use find -print0 piped to xargs -0. Both methods prevent word splitting and glob expansion, ensuring each filename is treated as a single argument. Unquoted expansions and simple IFS changes are unreliable because they do not handle all special characters, especially newlines. These techniques are essential for writing robust shell scripts.

Answer

Quote the variable expansion: "$filenames"

Answer

Set IFS to newline only and use unquoted $filenames

Answer

Use a for loop with unquoted $filenames

Question 4

A shell script must read configuration values from a file named config.env located in the same directory as the script. The script should not rely on the current working directory. Which two approaches correctly determine the directory containing the script so that config.env can be sourced reliably? (Choose two.)

Accepted Answer

SCRIPT_DIR=$(readlink -f "$0" | xargs dirname). To locate a script's directory independently of the current working directory, the path must be resolved to an absolute form. Combining cd, dirname, and pwd achieves this by changing into the script's directory and printing the absolute path. Similarly, readlink -f resolves the script's full path, and dirname extracts the directory. Relative approaches such as dirname "$0" or ${0%/*} depend on how the script was invoked and may yield relative paths.

Answer

SCRIPT_DIR=${0%/*}

Answer

SCRIPT_DIR=$PWD

Answer

SCRIPT_DIR=$(dirname "$0")

Question 5

A junior administrator needs to archive the contents of /data into a single compressed file that preserves ownership, permissions, and directory structure, and then verify the archive's integrity without extracting it. Which two commands together accomplish this? (Choose two.)

Accepted Answer

tar -czvf /backup/data.tar.gz -C /data .. Creating the archive with tar -czvf and -C /data . stores the contents with relative paths while retaining ownership and permissions. Verifying with tar -tzvf decompresses and reads every member, so corruption or truncation surfaces as an error without writing anything to disk. Extraction-based commands such as tar -x, cpio -i, or gzip -d change or destroy files and therefore do not meet the verify-in-place requirement.

Answer

cpio -idmv < /backup/data.tar.gz

Answer

tar -xzvf /backup/data.tar.gz -C /tmp/verify

Answer

gzip -d /backup/data.tar.gz

Question 6

A system administrator needs to change the permissions of a script named backup.sh so that the owner can read, write, and execute it, while group members and others have no permissions. Which command accomplishes this?

Accepted Answer

chmod 700 backup.sh. The correct permission set is owner read, write, execute; group none; others none. In octal, read=4, write=2, execute=1, so owner gets 7, group 0, others 0, resulting in 700. The chmod command with 700 achieves this. Other options either grant too many permissions (777), too few (600 lacks execute), or use incorrect symbolic mode. This is a fundamental Linux permission task.

Answer

chmod 600 backup.sh

Answer

chmod 777 backup.sh

Answer

chmod u=rwx,go= backup.sh

Question 7

A shell script processes a list of filenames stored in a variable. Some filenames contain spaces. The script currently uses `for file in $list; do ...; done`. Which change will correctly handle filenames with spaces?

Accepted Answer

Use `while IFS= read -r file; do ...; done < <(printf '%s
' "$list")`. The while read loop with IFS= and -r is the standard idiom for iterating over a list where items may contain spaces or special characters. It reads each line as a whole, preserving whitespace. The other options either treat the entire list as one item, split on spaces, or add unnecessary and harmful splitting, so they do not correctly handle filenames with spaces.

Answer

Use `for file in $list; do set -- $file; ...; done`

Answer

Use `for file in "$list"; do ...; done`

Answer

Use `for file in $(echo $list); do ...; done`

Question 8

A system administrator writes a script that extracts data from a CSV file and inserts it into a database. The script works correctly when run manually but fails when executed by cron. Which environment variable is most likely causing the issue?

Accepted Answer

PATH. When a script runs manually, the user's interactive shell inherits a fully populated PATH environment variable that includes directories like /usr/local/bin, /usr/bin, and possibly custom script directories. Cron jobs, however, execute with a minimal environment, and the default PATH for cron is often just /usr/bin:/bin. If the script relies on commands (e.g., mysql, psql, or custom scripts) located outside these directories, cron will fail with a 'command not found' error. Setting the full PATH explicitly inside the script or in the crontab file resolves the issue.

Answer

SHELL

Answer

LANG

Answer

HOME

Question 9

A developer needs to ensure a bash script exits immediately if any command fails, and also prints each command before executing it. Which set of shell options should be used at the beginning of the script?

Accepted Answer

set -ex. `set -ex` combines two essential shell options: `-e` (errexit) causes the script to exit immediately if any command returns a non-zero exit status, and `-x` (xtrace) prints each command (after expansion) to stderr before executing it. This is the standard way to achieve both behaviors in a single line, as required by the question.

Answer

set -e

Answer

set -vx

Answer

set -ux

Question 10

A script contains the following line: for i in $(cat file.txt); do echo $i; done. The file file.txt contains a single line with multiple words. How many times will the loop execute?

Accepted Answer

Equal to the number of words in the file. The command substitution $(cat file.txt) expands to the content of file.txt, which is a single line with multiple words. The for loop iterates over each word (separated by whitespace) in the expanded string, not over lines. Therefore, the loop executes once per word in the file.

Answer

Equal to the number of lines in the file

Answer

Once

Answer

The loop will not execute

Question 11

Which THREE statements are true about the sed command?

Accepted Answer

sed -i 's/foo/bar/g' file.txt replaces all occurrences of foo with bar in the file.. Option B is correct because the -i flag enables in-place editing, so sed -i 's/foo/bar/g' file.txt rewrites file.txt directly, replacing every occurrence of foo with bar due to the g (global) flag. Option D is correct because the address /^#/ matches lines beginning with # and the d command deletes them, so sed '/^#/d' file.txt removes comment lines from the output. Option E is correct because -n suppresses default output and the address range 3,5 with the p command prints only lines 3 through 5. Option A is wrong because without -i sed writes results to stdout, leaving file.txt unchanged. Option C is wrong because sed uses basic regular expressions by default; extended regex requires the -E or -r option.

Answer

sed 's/old/new/g' file.txt permanently changes the file.

Answer

sed uses extended regular expressions by default.

Question 12

A system administrator needs to ensure that a bash script continues executing even if any command in the script fails. Which of the following should be used at the beginning of the script?

Accepted Answer

set +e. `set +e` disables the 'exit on error' behavior in a bash script, allowing the script to continue executing even if a command returns a non-zero exit status. By default, bash scripts do not exit on error, but if `set -e` is used elsewhere, `set +e` explicitly turns that off to ensure the script continues despite failures.

Answer

trap 'echo error' ERR

Answer

unset -e

Answer

set -e

Answer

# set +e

Question 13

Match each package manager to its associated distribution family.

Accepted Answer

APT: Debian-based distributions. Common package managers and their distribution families: APT (Debian), YUM/DNF (Red Hat), ZYpp (SUSE), pacman (Arch). Distractor options swap these associations.

Answer

APT: Red Hat-based distributions

Answer

YUM: SUSE-based distributions

Question 14

An administrator wants to list all lines in a log file that do NOT contain the word 'ERROR'. Which command should be used?

Accepted Answer

grep -v 'ERROR' logfile. The `-v` flag inverts the match, causing `grep` to output only lines that do NOT contain the pattern 'ERROR'. This is the standard way to exclude lines matching a pattern in a file.

Answer

grep -i 'ERROR' logfile

Answer

grep -w 'ERROR' logfile

Answer

grep 'ERROR' logfile

Question 15

In a bash script, a variable 'file' is set to '/var/log/syslog'. Which expansion will yield the string '/var/log'?

Accepted Answer

${file%/*}. The `${file%/*}` expansion uses the `%` operator to remove the shortest suffix matching the pattern `/*`, which matches the last slash and everything after it. Since `file` is `/var/log/syslog`, this removes `/syslog`, leaving `/var/log`. This is a standard parameter expansion in bash for stripping a trailing path component.

Answer

${file##*/}

Answer

${file%%/*}

Answer

${file#*/}