Linux Essentials Practice Flashcards

VOCABULARY flashcards based on Linux Essentials lecture notes covering file systems, commands, permissions, and distributions.

/var

A directory that must be mounted with read and write access if it resides on its own dedicated file system.

passwd

The command used to either change a user's password or lock a user account.

Distribution's package repository

The preferred source for the installation of new applications in a Linux based operating system.

/etc/passwd

The configuration file where the numerical user ID, the username, and the user's default shell are stored.

/proc/

A directory that contains one directory per running process.

Solid state disks

Storage devices that provide faster access to stored data than hard disks and contain no moving parts.

Hard disk drives

Storage devices that utilize a motor and moving parts to function.

CentOS

A Linux distribution derived from Red Hat Enterprise Linux that allows users to apply their RHEL knowledge for free.

For loop structure

A shell script sequence typically following the format: for file in *.txt do echo $i done.

USERNAME=bob

The specific command used to set the variable USERNAME to the value bob.

chmod 654

The command that sets permissions on a regular file to -rw-r-xr--.

man

The command used to display manual pages for system commands and programs.

Symbolic link

A type of link in a Linux file system that has the ability to point to a file on another file system.

find /home -name foo.txt

The command used to search for a file named foo.txt under the /home directory.

tar -cf

The command flags used to create an archive file from the contents of a directory.

$$21398$$

An example of a possible value for a process ID (PID) on a Linux system.

Typical shell script

A file that has the executable permission bit set and begins with the two character sequence #!.

Raspberry Pi Storage

Stored on a removable SD card which is inserted into the Raspberry Pi device.

dmesg

The command used to display the content of the Linux kernel's ring buffer.

Kernel ring buffer

A memory area containing kernel messages that might not display older information once overwritten by newer data.

Linux hardware drivers

Software components that are either compiled into the Linux kernel or loaded as kernel modules.

sort

The command used to put the lines of a file, such as data.csv, into alphabetical order.

pwd

The command that displays the absolute path to the current working directory.

info

Along with man, this command is used to get information on the proper use of directory commands like ls.

chown

The command used to change the ownership of a file to a new owner, such as tux.

Inkscape

A program categorized as a graphical editor for vector graphics.

ls -R

The parameter of the ls command that prints a recursive listing of a directory's content.

Web browser cookies

Data elements that support the identification and tracking of users and are considered dangerous.

zip

The command used to create an archive containing all files in the current directory ending in .txt.

SATA bus

The type of bus used to connect hard disk drives with the motherboard.

useradd -m

The command that adds a new user and creates their home directory with default configuration files.

cp *.txt /tmp/

The command used to copy all files ending in .txt from a directory to the /tmp/ directory.

rwxrwxrwt

The specific permissions set on the /tmp/ directory.

DHCP

A protocol used for the automatic configuration of IP addresses.

bash test.sh

A method to execute a valid shell script file named test.sh from the current directory.

/dev/sda2

A device path representing a specific partition on a hard disk.

-h or --help

Options typically used with Linux commands to display information regarding their usage.

$$0$$

The numerical user ID (UID) of the root user.

/usr/share/doc/

A directory containing information, documentation, and example configuration files for installed software packages.

Private web browser window

A browser session that does not store cookies persistently or keep records in the browser history.

/etc/skel

A directory containing default configuration files copied to a new user's home directory during account creation.

Apache

A popular program used as a web server.

NGINX

A popular program used as a web server.

cat 'Texts 2.txt'

A command for outputting file content that uses quotes to handle spaces in the filename.

grep -i

The command used to find lines in a file that contain a specific term regardless of case.

Free Software

Software that grants users the freedom to modify the code.

AAAA

A DNS record type that holds an IPv6 address.

$$\backslash$$

The single character used to split a long command across multiple lines at the shell.

Free Software license

A legal agreement defining the conditions for modifying and distributing licensed software.

/etc/group

A file that acts as a source of information for user group IDs and names.

Hashed form

The only state in which Linux passwords should be stored on the system.

File ownership

The principle that each file is owned by exactly one user and one group.

rm -r

A command used to remove a directory, such as Downloads, and its contents.

rmdir

A command used to remove a directory provided that it is empty.

top

A utility that displays running processes ordered by CPU or RAM consumption.

Former owner's UID

The identifier shown when listing details of a file whose previous owner's account has been deleted.

Ubuntu Linux LTS

A Linux distribution that provides long-term support and security updates over several years.

Red Hat Enterprise Linux

An enterprise-grade Linux distribution that provides long-term security updates.

Execute bit

The permission bit that must be set to avoid a 'Permission denied' error when running a shell script.

tar -z

The tar option used to handle gzip compression.

tar -j

The tar option used to handle bzip2 compression.

PTR record

A DNS record used to assign hostnames to IP addresses in reverse DNS lookups.

IaaS Cloud Provisioning

The process of creating a new Linux instance using pre-prepared images from a cloud provider.

Recursive directory listing

A directory listing that includes the content of all sub-directories.

export PATH

The command used to add a new directory to the PATH environment variable.

host

A command used to resolve a DNS name to its corresponding IP address.

$0$ return value

The value returned by a shell script to indicate successful execution.

tar -xzf

The command string used to extract the contents of a compressed archive file ending in .tar.gz.

rpm

The package management tool used in Red Hat-based Linux systems.

su

The command that allows a user to run a shell or command as another user.

Linux distribution

A bundling of the Linux kernel, system utilities, and other software.

export-logs | sort

A command sequence that pipes output to be sorted into alphabetical order.

ls -a

A command that displays file names only, including hidden files, without extra details.

PaaS

Platform as a Service; a typical offering by public cloud providers.

IaaS

Infrastructure as a Service; a typical offering by public cloud providers.

SaaS

Software as a Service; a typical offering by public cloud providers.

export MYVAR=value

The command syntax used to set a variable so it is accessible by a shell script.

last

A command that displays login history, including the user, tty, and session duration.

free

A command that displays information regarding total, used, and available system memory.

$?$ operator

The regular expression operator that matches the preceding character either zero or one time.

$$\#$$

The character in a shell prompt indicating the user has root privileges.