Linux Administration and Commands Practice Exam

Flashcards covering Linux commands, directories, system configuration, processes, and network management based on lecture quiz feedback and questions.

Sticky Bit (chmod 1777)

A permission set on a directory that allows all users to add files, but ensures only the file owners can delete their own files; it is represented by a lowercase $t$ in the others permissions.

gdisk

A command used to convert an MBR partition to GPT, which destroys all existing MBR partitions on the disk.

updatedb

A command usually run daily by cron to update the default database ($mlocate.db$) so that the locate command can find files on the system.

/usr

A directory under the root folder that contains system commands and utilities for a Linux operating system.

echo command

A utility used to display text (with or without quotation marks) or shell variables (using the $$ sign); it can also be followed by a semicolon to run subsequent commands.

Shell

An interface that interacts with the user, accepts commands, and passes them to the kernel for processing.

cd ../..

A command used to move back two previous directories from the current working directory.

cal

A command that displays a calendar for the current month.

pwd

An abbreviation for 'present working directory,' used to show the full path of the current subdirectory.

/boot

A required separate partition for using Logical Volume Management (LVM) on Linux; it also contains the Linux kernel.

ls -i

An option for the ls command that displays the inode numbers for files; hard links to the same file will share the same inode number.

Symbolic Link Permissions

When displayed with ls -l, these links start with a lowercase $l$ and typically show read, write, and execute bits set for user, group, and others ($lrwxrwxrwx$).

diff

A command used to compare the contents of two text files to identify changes between them.

fsck

A command used to check and repair various kinds of filesystems on Linux for errors.

.iso

A disk image file format commonly used as installation media for virtual machines or burned to optical discs.

parted (print command)

A command used within the parted utility to display a list of existing partitions on a hard drive.

exit

The command used to close or exit the current shell interface.

Options

Specific letters that start with a dash ($-$) and appear after command names to modify the command's behavior.

& (Ampersand)

A metacharacter used at the command line to indicate background command execution.

tune2fs -i 14d

A command and option combination used to set a full filesystem check to occur every $14$ days.

tail -5

A command used to display the last five lines of a text file.

mkdir -p

An option used with the mkdir command to create parent directories if they do not already exist.

umask 0177

A setting that results in new files receiving default permissions of $-rw-------$, masking off execute for user and all permissions for group/others.

quotacheck

A utility used to scan a filesystem for disk usage, as well as to create, check, and repair quota files.

; (Semicolon)

A metacharacter used as a command terminator that allows two commands to be run in consecutive order.

memtest86

A utility that performs a thorough check of the system RAM for hardware errors.

chmod 740

A command that sets permissions where the owner has read/write/execute ($7$), the group has read-only ($4$), and others have no access ($0$).

/var/lib/mlocate/mlocate.db

The complete path and filename for the database used by the locate and mlocate commands.

tac

The cat command spelled backwards, used to display a text file in reverse order.

ln -s

The command used to create a symbolic link from an original file to a new link name.

blkid

A command used to display the filesystem and partition Universally Unique Identifiers (UUIDs) on a Linux system.

chown :root

A command syntax used to set the group ownership of a file to root without changing the user owner.

/root

The directory specified by the Filesystem Hierarchy Standard as the home directory for the root user.

umount

The command used to properly disconnect or unmount a filesystem, such as an external USB drive.

/etc/updatedb.conf

The configuration file used to define which directories the locate command should exclude from its search database.

@ (At Sign)

The special character displayed by the ls -F command to indicate a linked file.

vmlinuz

The filename of the executable file containing the Linux kernel.

chmod 7777

A command that sets all special permissions (SUID=4, SGID=2, sticky=1) as well as full read/write/execute permissions for everyone.

man uname

The command used to view the manual pages for the uname utility, which displays system and kernel information.

/lost+found/

A directory created by default on ext2, ext3, or ext4 filesystems used by the fsck utility for recovered file fragments.

stat

A command effective at identifying and displaying detailed information about different types of files.

mv

A command used to move files between directories or rename a file by moving it to a new filename.

vi (A key)

While in command mode in the vi editor, this key changes to insert mode and places the cursor at the end of the current line to append text.

/dev/sdb3

The device file representation for the third partition on the second SATA drive.

mkfs.ext2

The default filesystem type created if the mkfs command is executed with only a block device name specified.

/etc/fstab

The configuration file where entries are added to automatically mount partitions at system boot.

/var

A directory under root used to store log files, spools, and print server data.

ps -e

An option used with the ps command to display a complete list of processes, including those that do not run on a terminal (daemons).

/proc/meminfo

A file in the proc directory that contains information regarding physical and virtual memory (RAM) on the system.

DISPLAY variable

A system variable that contains information about which X server a client is supposed to connect to by default.

\t

A common escape sequence used with the echo command to display a horizontal tab.

SIGQUIT

A kill signal that terminates a process and saves its memory information to a file called 'core' in the current working directory.

LANG

An option passed from the GRUB2 configuration file to the Linux kernel to set the system locale.

pkill

A command used to terminate a process by specifying its process name.

Epoch time

The number of seconds since January $1$, $1970$, which is considered the birth date of UNIX.

read -s -p

Options used in a shell script to create a prompt ($-p$) and ensure the input (like a password) remains secret ($-s$) by not displaying it on screen.

ioports

A file in the /proc directory that contains a list of memory address ranges reserved for device use.

seq 7

A command that displays the numbers $1$ through $7$ on separate lines.

nl

A command that displays the contents of a file while adding a line number to the left side of each line.

(Double Greater Than)

A redirection operator used to take output from a command and append it to the end of a file.

/etc/localtime

A binary file containing the rules for calculating time based on the local time zone relative to epoch time.

GOK

Acronym for the GNOME On-screen Keyboard.

XFCE

A lightweight desktop environment designed to use very few system resources.

| (Pipe)

A metacharacter used to send the output of one command to another as input.

/etc/cron.monthly

The directory where system administrators store scripts that should be executed once every month by the cron daemon.

r (in top)

The key pressed while the top command is running to 'renice' or change the nice value of a process.

if construct

A shell script element used to determine if two values are equal and conditionally run a set of commands.

pstree

A command that displays the lineage of a process by tracing Parent Process IDs (PPIDs) back to the init daemon.

crontab -l

The command used to display the cron jobs for the currently logged-in user.

(Pound Sign)

A character placed at the beginning of a line in a shell script to mark it as a comment.

timeout

An option in the GRUB Legacy configuration file that sets how many seconds the boot menu displays before loading the default image.

dmesg

A command used to display messages generated by the kernel during the boot sequence.

Zombie process

A process state where the process has finished execution but is waiting for its parent process to release its PID.

Cinnamon

The default desktop environment used by the Linux Mint distribution.

2 (Redirection)

The numeric descriptor representing stderr (standard error) at the command line.

fg

The command used to bring a background job to the foreground of the terminal.

/etc/inittab

The file where the default runlevel is set on some Linux systems.

tee

A command used to send output to the screen while simultaneously writing it to a file.

/usr/share/zoneinfo

The directory containing files for all time zones recognized by the Linux operating system.

menu.lst

The file that holds configuration information for GRUB Legacy on Ubuntu Linux systems.

Nice Value 19

The highest nice value possible, which results in a lower priority for a process.

lsof

An abbreviation for 'list open files,' used to see which files are currently being used by a specific PID.

kill -9

The command and signal (SIGKILL) used to kill a process by sending its resources to /dev/null.

mutter

The default window manager used by the GNOME version $3$ desktop environment.

.gitignore

A file used to list filenames that should not be staged when running the git add command.

Upstart

A replacement for the init daemon responsible for starting/stopping services and supervising them during system operation.

systemctl set-default

The command used to set the default runlevel on modern Linux systems using systemd.

Click Assist

An accessibility feature that simulates a right click by holding down the left mouse button.

TZ variable

A system variable that can be modified to override the default system timezone within a specific shell.

ctrl-c

A key combination that sends the SIGINT signal to exit out of programs like top.

compress -v

The option used with the compress command to display the compression ratio for each file.

curl

A command-line tool used to retrieve or obtain a Web page from a BASH prompt.

/etc/systemd/journald.conf

The path to the configuration file for the journald logging service.

APIPA

Automatic Private IP Addressing; it uses the range $169.254.0.0$ through $169.254.255.255$ when DHCP is unavailable.

Wheel Group

A special group that grants its members the permission to run su and sudo commands.

tar -czvf

A tar command combination that creates ($c$) a gzipped ($z$) archive with a specific filename ($f$) while providing verbose ($v$) output.

/var/log/btmp

The log file that records failed login attempts on a Linux system.

Zypper

The default package manager for SUSE and openSUSE distributions used to install RPM packages.

ifup eth0

The command used to bring the eth0 ethernet interface back up after it has been shut down.

cloud-init

A tool that reads YAML configuration files at boot time to perform administrative tasks, such as adding apps or modifying settings.