LPIC-1 GNU and Unix Commands — All Questions With Answers

Question 1

A systems administrator needs to change the permissions of the file /home/user/script.sh so that the owner can read, write, and execute; the group can read and execute; and others have no access. Which command accomplishes this?

Accepted Answer

chmod 750 /home/user/script.sh. Chmod 750 sets the permissions to rwxr-x---, which gives the owner read, write, and execute (7), the group read and execute (5), and others no access (0). This matches the requirement exactly.

Answer

chmod 755 /home/user/script.sh

Answer

chmod 770 /home/user/script.sh

Answer

chmod 741 /home/user/script.sh

Question 2

Which TWO commands can be used to view the contents of a compressed file named archive.tar.gz without extracting it to disk?

Accepted Answer

tar -tzf archive.tar.gz. The `tar -tzf` command lists the contents of a tar archive compressed with gzip without extracting it. The `-t` flag tells tar to list the table of contents, `-z` handles the gzip decompression on the fly, and `-f` specifies the archive file. This is the standard, single-command method for viewing the contents of a `.tar.gz` file without writing any files to disk.

Answer

gzip -d archive.tar.gz

Answer

bunzip2 -c archive.tar.gz | tar -t

Answer

gunzip -l archive.tar.gz

Question 3

Refer to the exhibit. An administrator needs to edit /etc/example.conf to change setting1 to 'production' and add a new line 'setting2=value' after the include line. The file must be edited in place without creating a backup. Which command sequence achieves this?

Accepted Answer

sed -i 's/setting1=default/setting1=production/' /etc/example.conf; sed -i '/^include /a
setting2=value' /etc/example.conf. The first sed command uses the -i flag to edit the file in place without a backup, and the substitution 's/setting1=default/setting1=production/' changes the existing setting. The second sed command uses the 'a' (append) command after the line matching '^include ' to add the new line 'setting2=value' after it, also with -i to avoid creating a backup.

Answer

sed -i 's/setting1=default/setting1=production/' /etc/example.conf; sed -i '/^include /i
setting2=value' /etc/example.conf

Answer

sed -i.bak 's/setting1=default/setting1=production/' /etc/example.conf; sed -i.bak '/^include /a
setting2=value' /etc/example.conf

Answer

sed -i.bak 's/setting1=default/setting1=production/' /etc/example.conf; sed -i.bak '/^include /a
setting2=value' /etc/example.conf

Question 4

You are a Linux administrator for a company that runs a web server on a system with limited disk space. The web server logs are stored in /var/log/httpd/access_log and grow quickly. The operations team requires that the most recent logs be available for troubleshooting, but logs older than 7 days must be compressed to save space. You decide to implement log rotation using logrotate. The logrotate configuration file for httpd currently contains:

/var/log/httpd/*.log {
    daily
    rotate 7
    compress
    delaycompress
    missingok
    notifempty
    sharedscripts
    postrotate
        /bin/systemctl reload httpd 2>/dev/null || true
    endscript
}

After applying this configuration, you notice that log files are being compressed immediately instead of after one rotation. What is the most likely cause and the correct step to fix this?

Accepted Answer

Change the rotation frequency to 'weekly' so that the most recent week's logs remain uncompressed and older logs are compressed.. The issue is that with daily rotation, the delaycompress directive delays compression by only one rotation (one day). This means that rotated logs are compressed after one day, not after the desired 7 days. To meet the requirement that logs older than 7 days are compressed, the rotation frequency should be changed to weekly. With weekly rotation, delaycompress delays compression by one week, so logs younger than 7 days remain uncompressed and the most recent week's logs are available for troubleshooting.

Answer

Remove the 'sharedscripts' directive to ensure the postrotate script runs for each log file individually.

Answer

Remove the 'delaycompress' directive to ensure compression occurs at each rotation.

Answer

Add the 'copytruncate' directive to avoid moving the log file, allowing the web server to continue writing to the same file.

Question 5

Arrange the steps to configure a static IP address on a Linux system using the command line.

Accepted Answer

Step 1: Open the network configuration file (e.g., /etc/network/interfaces).
Step 2: Configure the interface with static IP, netmask, gateway, and DNS.
Step 3: Save and exit the file.
Step 4: Restart the networking service.. Static IP configuration requires editing the appropriate config file, then restarting networking to apply changes.

Answer

Step 1: Restart the networking service.
Step 2: Open the network configuration file.
Step 3: Configure the interface with static IP, netmask, gateway, and DNS.
Step 4: Save and exit the file.

Answer

Step 1: Open the network configuration file.
Step 2: Save and exit the file.
Step 3: Configure the interface with static IP, netmask, gateway, and DNS.
Step 4: Restart the networking service.

Answer

Step 1: Configure the interface with static IP, netmask, gateway, and DNS.
Step 2: Restart the networking service.
Step 3: Open the network configuration file.
Step 4: Save and exit the file.

Question 6

Order the steps to recover a forgotten root password on a Linux system.

Accepted Answer

1. Reboot the system. 2. Interrupt the GRUB bootloader. 3. Add 'init=/bin/bash' to the kernel command line. 4. Boot the system. 5. Remount the root filesystem as read-write. 6. Change the root password using passwd. 7. Reboot the system.. Recovery involves booting into a shell with root access, remounting read-write, and changing the password.

Answer

1. Reboot the system. 2. Interrupt the GRUB bootloader. 3. Add 'init=/bin/bash' to the kernel command line. 4. Boot the system. 5. Change the root password using passwd. 6. Remount the root filesystem as read-write. 7. Reboot the system.

Answer

1. Reboot the system. 2. Boot into single-user mode from GRUB. 3. Remount the root filesystem as read-write. 4. Change the root password using passwd. 5. Reboot the system.

Answer

1. Reboot the system. 2. Edit GRUB to add 'single' to the kernel line. 3. Boot the system. 4. Remount the root filesystem as read-write. 5. Change the root password using passwd. 6. Reboot the system.

Question 7

Match each Linux runlevel to its typical description.

Accepted Answer

runlevel 0: Halt. Standard SysV init runlevels: 0 (halt), 1 (single-user), 3 (multi-user with network), 5 (graphical multi-user), 6 (reboot). Common confusions involve swapping definitions between runlevels 3 and 5.

Answer

runlevel 3: Graphical multi-user mode

Answer

runlevel 5: Multi-user mode with network

Question 8

Match each device file naming pattern to its device type.

Accepted Answer

/dev/sda: SATA/SCSI hard disk. Common Linux device naming conventions: /dev/sdX for SATA/SCSI, /dev/hdX for IDE, /dev/ttySX for serial ports, /dev/srX for optical drives, /dev/nvmeXnY for NVMe. Be cautious not to confuse with floppy (/dev/fdX) or other types.

Answer

/dev/sr0: Floppy disk

Question 9

A systems administrator needs to find all files in /var/log that were modified in the last 24 hours and contain the word 'error'. Which command accomplishes this?

Accepted Answer

find /var/log -mtime 0 -exec grep -l 'error' {} \;. It uses `find` with `-mtime 0` to locate files modified within the last 24 hours, then pipes each found file to `grep -l` to print only filenames containing 'error'. The `-exec` option runs `grep` on each file individually, and `-l` ensures only matching filenames are output, not the matching lines.

Answer

grep -r 'error' /var/log -mtime 0

Answer

find /var/log -mmin 1440 -exec grep 'error' {}

Answer

ls -l /var/log | grep error

Question 10

An administrator wants to change the ownership of a file to user 'jane' and group 'staff'. Which command should be used?

Accepted Answer

chown jane:staff file. The `chown` command with the syntax `chown user:group file` changes both the user and group ownership of a file in a single command. This is the standard POSIX syntax, where a colon separates the user and group names, allowing the administrator to set ownership to user 'jane' and group 'staff' atomically.

Answer

chown jane.staff file

Answer

chgrp jane staff file

Answer

chown jane staff file

Question 11

A developer is troubleshooting a shell script that uses the variable $HOME but it outputs nothing when the script runs. The script is executed with ./script.sh from an interactive shell. What is the most likely cause?

Accepted Answer

The user has no home directory. In an interactive shell, the HOME variable is typically exported by the login process and inherited by child processes. The most likely cause for $HOME being empty is that the user has no home directory defined in the password database (or the directory doesn't exist), which can cause the variable to be empty or unset in some configurations. Options A and B would not cause $HOME to be empty; using sh instead of bash or running with sudo would still provide a HOME value (possibly different) or set it to root's home.

Answer

The script is run with sh instead of bash

Answer

The script is run with sudo

Answer

The HOME variable is not exported

Question 12

An administrator needs to copy a directory hierarchy from one server to another over SSH, preserving permissions, ownership, and timestamps. Which command is most appropriate?

Accepted Answer

tar cf - /source | ssh user@dest "tar xf - -C /target". It uses `tar` to create an archive of the source directory, pipes it over SSH, and extracts it on the remote server with `tar xf - -C /target`. This method preserves all file metadata (permissions, ownership, timestamps) because `tar` captures and restores these attributes by default, and the pipe over SSH transfers the raw archive without any transformation. Unlike `scp` or `rsync` (without root privileges), this approach can preserve ownership even when the user is not root, as long as the remote `tar` runs with appropriate privileges.

Answer

cp -a /source /mnt/remote

Answer

scp -rp /source user@dest:/target

Answer

rsync -avz /source user@dest:/target

Question 13

An administrator runs the command 'find / -name "*.conf" 2>/dev/null | head -n 10' and notices that the command returns very quickly. Which statement best describes what happened?

Accepted Answer

It scans the entire filesystem but stops after sending the first 10 lines to head due to a broken pipe.. The `find` command starts scanning the entire filesystem from root (`/`), but its output is piped to `head -n 10`, which reads only the first 10 lines and then closes the pipe. When `head` closes the pipe, `find` receives a SIGPIPE signal (broken pipe) and terminates early, so the command returns very quickly without scanning the entire filesystem.

Answer

It lists 10 .conf files only from the current directory because the path is /.

Answer

It lists all .conf files in the filesystem because head only affects output, not find.

Answer

It lists only the first 10 .conf files found in the filesystem.

Question 14

A script uses 'set -e' and then executes 'grep pattern file'. If the pattern is not found, the script exits. Which of the following modifications would prevent the script from exiting while still allowing detection of the pattern's absence?

Accepted Answer

set +e; grep pattern file; exit_code=$?; set -e. It temporarily disables 'set -e' with 'set +e', runs the grep command, captures its exit code in a variable, then re-enables 'set -e'. This allows the script to continue executing after a non-zero exit from grep, while still preserving the exit code for later conditional checks. The other options either fail to preserve the exit code or do not prevent the script from exiting under 'set -e'.

Answer

grep -q pattern file || true

Answer

grep pattern file; exit_code=$?

Answer

grep pattern file | head -1

Question 15

Refer to the exhibit. Which file has a special permission that allows a user to execute the file with the privileges of the file owner?

Accepted Answer

/usr/bin/su. The /usr/bin/su command has the SUID (Set User ID) special permission set (typically mode 4755). This allows any user who executes the file to run it with the effective user ID of the file owner (root), enabling privilege escalation to perform administrative tasks. The SUID bit is represented by an 's' in the owner's execute position when viewed with ls -l.

Answer

/usr/bin/myapp

Answer

/tmp/shared

Answer

None of the above

Question 16

Refer to the exhibit. The process with PID 1234 is in state 'Z'. What is the most likely cause and appropriate action?

Accepted Answer

The process is a zombie; the parent process must be killed or wait for it to be reaped.. In Linux process states, 'Z' indicates a zombie process, which is a child process that has terminated but whose exit status has not yet been read by its parent process via the wait() system call. The correct action is to either kill the parent process (so that the zombie is reaped by init) or ensure the parent calls wait() to reap the child. Option D correctly identifies this.

Answer

The process is stopped; use kill -CONT to continue.

Answer

The process is a daemon; it should be restarted.

Answer

The process is sleeping; wait for it to become ready.

Question 17

Refer to the exhibit. Which file system is full and what is the likely consequence if the administrator does not take action?

Accepted Answer

/dev/sdb1 is full; applications writing to /var may fail.. The exhibit shows that /dev/sdb1, mounted on /var, has 0% available space (100% used). The /var directory stores variable data such as logs, spool files, and temporary files. If /var fills up, critical services like syslog, cron, or package managers (e.g., apt, yum) cannot write to their log or spool files, causing applications that depend on /var to fail. This is why option D is correct.

Answer

Both are full; system will crash.

Answer

/dev/sda1 is full; system may become unstable.

Answer

Neither is full; available space is sufficient.

Question 18

Which TWO commands can be used to display the contents of a compressed file without decompressing it to disk? (Choose two.)

Accepted Answer

zcat file.gz. A is correct because `zcat` reads a gzip-compressed file and writes its decompressed content to standard output without saving the decompressed data to disk. This allows you to view the contents of `file.gz` directly in the terminal or pipe it to other commands.

Answer

gzip -d file.gz

Answer

tar -xzf file.tar.gz

Answer

uncompress file.Z

Question 19

Which TWO of the following are valid methods to run a shell script named 'script.sh' using the bash shell, assuming the script has execute permission? (Choose two.)

Accepted Answer

./script.sh. './script.sh' explicitly invokes the script using the current shell's shebang interpreter (e.g., #!/bin/bash) and requires execute permission. Option E is correct because 'bash script.sh' runs the script as an argument to the bash interpreter, which reads and executes the file line by line, also requiring execute permission.

Answer

sh script.sh

Answer

script.sh (if in PATH)

Answer

source script.sh

Question 20

Which THREE of the following are correct features of the 'grep' command? (Choose three.)

Accepted Answer

-i makes the search case-insensitive. The `-i` flag in `grep` performs case-insensitive matching, so patterns like 'error' will match 'Error', 'ERROR', etc. This is a common requirement when searching log files where case may vary.

Answer

-l prints line numbers of matches

Answer

-r enables regular expression matching

LPIC-1 GNU and Unix Commands — All Questions With Answers

A systems administrator needs to change the permissions of the file /home/user/script.sh so that the owner can read, write, and execute; the group can read and execute; and others have no access. Which command accomplishes this?

Which TWO commands can be used to view the contents of a compressed file named archive.tar.gz without extracting it to disk?

Refer to the exhibit. An administrator needs to edit /etc/example.conf to change setting1 to 'production' and add a new line 'setting2=value' after the include line. The file must be edited in place without creating a backup. Which command sequence achieves this?

Arrange the steps to configure a static IP address on a Linux system using the command line.

Order the steps to recover a forgotten root password on a Linux system.

Match each Linux runlevel to its typical description.

Match each device file naming pattern to its device type.

A systems administrator needs to find all files in /var/log that were modified in the last 24 hours and contain the word 'error'. Which command accomplishes this?

An administrator wants to change the ownership of a file to user 'jane' and group 'staff'. Which command should be used?

A developer is troubleshooting a shell script that uses the variable $HOME but it outputs nothing when the script runs. The script is executed with ./script.sh from an interactive shell. What is the most likely cause?

An administrator needs to copy a directory hierarchy from one server to another over SSH, preserving permissions, ownership, and timestamps. Which command is most appropriate?

An administrator runs the command 'find / -name "*.conf" 2>/dev/null | head -n 10' and notices that the command returns very quickly. Which statement best describes what happened?

A script uses 'set -e' and then executes 'grep pattern file'. If the pattern is not found, the script exits. Which of the following modifications would prevent the script from exiting while still allowing detection of the pattern's absence?

Refer to the exhibit. Which file has a special permission that allows a user to execute the file with the privileges of the file owner?

Exhibit

Refer to the exhibit. The process with PID 1234 is in state 'Z'. What is the most likely cause and appropriate action?

Exhibit

Refer to the exhibit. Which file system is full and what is the likely consequence if the administrator does not take action?

Exhibit

Which TWO commands can be used to display the contents of a compressed file without decompressing it to disk? (Choose two.)

Which TWO of the following are valid methods to run a shell script named 'script.sh' using the bash shell, assuming the script has execute permission? (Choose two.)

Which THREE of the following are correct features of the 'grep' command? (Choose three.)

A system administrator wants to list all files in a directory that have been modified in the last 24 hours. Which command would be most appropriate?

After receiving a compressed tarball archive.tar.gz from a colleague, you want to list its contents without extracting. Which command should you use?

A developer wants to change the ownership of all files in a directory tree to the user 'www-data' and group 'www-data', but only files that are currently owned by user 'nobody'. Which command accomplishes this?

Which command is used to compress a file with the highest compression ratio?

Which TWO commands can be used to display the contents of a compressed text file (e.g., .gz, .bz2) directly to standard output without decompressing to disk?

Which THREE of the following are valid symbolic mode expressions for the chmod command?

Refer to the exhibit. When will the backup script run?

Exhibit

A system administrator notices that the system's syslog messages are not being written to /var/log/messages. The rsyslog service is running. The administrator wants to check the configuration syntax of rsyslog. Which command should be used?

Which TWO of the following commands output the total number of lines in a file?

Refer to the exhibit. What will be the default permissions of a newly created file using the touch command?

Exhibit

Refer to the exhibit. A user runs 'python --version' and gets 'Python 3.9.1'. Which command would run Python 2 instead?

Refer to the exhibit. Which statement is true about SSH root login on this server?

Exhibit

Refer to the exhibit. The remount command fails. What is the most likely cause?

Exhibit

Refer to the exhibit. Which users are allowed to use the 'at' command?

Exhibit

Refer to the exhibit. The system fails to boot with an error 'UUID=e5f6g7h8 not found'. Which is the most likely cause?

Exhibit

Refer to the exhibit. A user reports that the 'myapp' command fails to run. Based on the output, what is the most likely cause?

Exhibit

Refer to the exhibit. Which of the following is true about SSH access to this server?

Exhibit

Refer to the exhibit. What is the expected outcome of the kill command?

Exhibit

Refer to the exhibit. The /var partition is nearly full. Which of the following is the most appropriate first step to free up space?

Exhibit

Refer to the exhibit. What type of traffic is being captured?

Exhibit

LPIC-1 GNU and Unix Commands — All Questions With Answers

A systems administrator needs to change the permissions of the file /home/user/script.sh so that the owner can read, write, and execute; the group can read and execute; and others have no access. Which command accomplishes this?

Which TWO commands can be used to view the contents of a compressed file named archive.tar.gz without extracting it to disk?

Refer to the exhibit. An administrator needs to edit /etc/example.conf to change setting1 to 'production' and add a new line 'setting2=value' after the include line. The file must be edited in place without creating a backup. Which command sequence achieves this?

Arrange the steps to configure a static IP address on a Linux system using the command line.

Order the steps to recover a forgotten root password on a Linux system.

Match each Linux runlevel to its typical description.

Match each device file naming pattern to its device type.

A systems administrator needs to find all files in /var/log that were modified in the last 24 hours and contain the word 'error'. Which command accomplishes this?

An administrator wants to change the ownership of a file to user 'jane' and group 'staff'. Which command should be used?

A developer is troubleshooting a shell script that uses the variable $HOME but it outputs nothing when the script runs. The script is executed with ./script.sh from an interactive shell. What is the most likely cause?

An administrator needs to copy a directory hierarchy from one server to another over SSH, preserving permissions, ownership, and timestamps. Which command is most appropriate?

An administrator runs the command 'find / -name "*.conf" 2>/dev/null | head -n 10' and notices that the command returns very quickly. Which statement best describes what happened?

A script uses 'set -e' and then executes 'grep pattern file'. If the pattern is not found, the script exits. Which of the following modifications would prevent the script from exiting while still allowing detection of the pattern's absence?

Refer to the exhibit. Which file has a special permission that allows a user to execute the file with the privileges of the file owner?

Exhibit

Refer to the exhibit. The process with PID 1234 is in state 'Z'. What is the most likely cause and appropriate action?

Exhibit

Refer to the exhibit. Which file system is full and what is the likely consequence if the administrator does not take action?

Exhibit

Which TWO commands can be used to display the contents of a compressed file without decompressing it to disk? (Choose two.)

Which TWO of the following are valid methods to run a shell script named 'script.sh' using the bash shell, assuming the script has execute permission? (Choose two.)

Which THREE of the following are correct features of the 'grep' command? (Choose three.)

A system administrator wants to list all files in a directory that have been modified in the last 24 hours. Which command would be most appropriate?

After receiving a compressed tarball archive.tar.gz from a colleague, you want to list its contents without extracting. Which command should you use?

A developer wants to change the ownership of all files in a directory tree to the user 'www-data' and group 'www-data', but only files that are currently owned by user 'nobody'. Which command accomplishes this?