Free LPI Linux Essentials Exam Flashcards

A complete operating-system package built around the Linux kernel, with user tools, libraries, a package system, and chosen defaults maintained by a project or vendor.

The kernel manages hardware and core system resources. A distribution combines that kernel with applications, libraries, installers, and package management.

Free and Open Source Software: software whose license grants users freedoms to run, study, modify, and redistribute the code under stated conditions.

A licensing approach that permits modification and redistribution but requires covered derivative work to preserve the same licensing freedoms.

A permissive license generally allows reuse with few conditions and does not require derivative code to use the same license.

They provide organized, signed collections of packages and metadata that package tools can search, install, and update.

Running one or more virtual computers on physical hardware through a hypervisor, so each guest can have its own operating system and allocated resources.

It is portable, automatable, scalable, and available in many open distributions, making it well suited to servers, virtual machines, and containers.

A graphical application that provides access to a text-based shell. The terminal displays input and output; the shell interprets commands.

A command interpreter that reads commands, expands expressions, starts programs, and supports scripting. Bash is a common Linux shell.

Options change how the command behaves; arguments identify what it should act on, such as a file, directory, pattern, or value.

It lists directories the shell searches, in order, when a command name is entered without an explicit path.

How the shell resolves a command name, such as an executable file, shell builtin, alias, or function.

They are reference manuals for commands, configuration files, system calls, and other interfaces. Use man followed by a topic name.

The absolute path of the shell's current working directory.

An absolute path begins at the root directory /. A relative path is interpreted from the current working directory.

. refers to the current directory; .. refers to its parent directory.

Their names begin with a dot. Many default directory listings omit them unless an option such as ls -a is used.

Zero or more characters within one path component. The shell expands the pattern to matching pathnames before running the command.

The current user's home directory when used unquoted in common shells such as Bash.

It combines files and directory trees into one archive and can extract them later. Compression is optional and uses a separate compression method.

They compress data streams or individual files. tar creates an archive structure; a compressor can then reduce that archive's size.

The | operator sends one command's standard output to the next command's standard input, allowing small tools to be combined.

It redirects standard output to a file and normally replaces that file's existing contents.

It redirects standard output by appending to the destination file instead of replacing its existing contents.

A separate output stream for diagnostics and errors. It can be redirected independently from normal standard output.

It selects input lines that match a pattern. Options can change matching behavior, such as ignoring case or showing line numbers.

A pattern language for describing text to match. Its metacharacters are interpreted by tools such as grep, not as ordinary literal characters.

Single quotes preserve nearly every character literally. Double quotes preserve spaces but still allow parameter and command expansion.

The $(command) form runs a command and substitutes its standard output into the surrounding command line.

It needs appropriate execute permission and normally a shebang naming its interpreter, such as #!/bin/bash.

CPU scheduling, memory, devices, filesystems, networking, and the interface between programs and hardware.

A running instance of a program with its own process ID, execution state, resource use, and security context.

ps reports a snapshot of selected processes. top provides a repeatedly updated interactive view of processes and system load.

A tool that installs, upgrades, removes, and tracks software packages while handling metadata and dependencies.

A defined region of a storage device that the operating system can treat as a separate block device.

The on-disk structure and rules used to organize file names, directories, data, and metadata within storage.

Attaching it at a directory called a mount point so its files become accessible within Linux's single directory tree.

System-wide configuration files. User data and ordinary application binaries belong elsewhere in the filesystem hierarchy.

Variable data that changes during operation, such as logs, caches, queues, and service state.

An IP address identifies a network interface numerically. A host name is a human-readable name that can be resolved to an address, commonly through DNS.

The superuser account with user ID 0 and broad authority over the system. Routine work should use a less-privileged account.

Policy-controlled execution of an authorized command with another user's privileges, commonly root, while supporting accountability through configuration and logs.

Public account records such as user name, numeric IDs, home directory, and login shell. Password hashes are normally stored separately in /etc/shadow.

They let permissions and resource access be assigned to a set of users rather than managed separately for every account.

Read permits viewing contents, write permits changing contents, and execute permits running the file as a program or script.

Read lists names; write, normally together with execute, permits creating, removing, or renaming entries; execute permits traversal and access by name.

For each user class, read is 4, write is 2, and execute is 1. Add the allowed bits, then provide owner, group, and other digits.

chown changes file ownership and can also set the group; chgrp changes only the group ownership.

It restricts removal or renaming of entries so that users cannot normally delete files owned by other users, even when the directory is writable by all.