Linux COL

What is Unix systems' modular design sometimes called?

Unix philosophy

What is the set of simple tools that the Unix operating system provides?

Core utils

What is the name of the GNU kernel?

Linux

The POSIX shell is the same as which shell?

Bourne Shell

What is the default shell on GNU/Linux?

BASH

True or False: The CLI, terminal, and shell are just different names for the same thing.

False

What is the root of the filesystem?

/

What is the name of the user that lives in kernel land?

root

What is the home directory of the root user?

/root

What is the administrator on a Linux system?

Sudo 'super user do' (anyone able to run 'sudo')

What is a device driver?

Translation layer between OS to User

What are the two types of device drivers?

User mode and kernel mode

Where are log files kept?

/var/log

Where are system configuration files located?

/etc

True or False - The /usr/bin directory contains required binaries.

False

What is the ~ short for?

Home directory of the user

What is a single dot short for?

Current working directory

Where does the absolute path for a file or directory start?

/

What is the fundamental interface between an application and the Linux kernel?

System calls

What is the command to pull up system calls by number on a Linux machine?

Ausyscall –dump

What is the name of the C library on GNU/Linux called?

Glibc

What is the file type for executable files in Unix/Linux?

elf

What is the GNU C library called?

glibc

What does the mmap system call do?

Map data to memory

True or False: A reboot is required when one installs a LKM?

False

What is the command to list loaded kernel modules?

lsmod

What does the .ko file extension stand for?

Kernel object

What are some of the common arguments used with the ps command?

Ef elf and aux

What is a type of process that runs in the background without any human interaction?

Daemon

What are the three types of login shells?

bash, gui, ssh

What shell actively reads commands from user input?

Interactive shell

What argument is used with the 'su' command to open a BASH login?

-, -l, –login

What argument opens a BASH login with the 'bash' command?

Bash -l, bash –login

What is the restricted BASH shell called?

rbash

What command is used to print environmental variables?

env, printenv

What environmental variable is checked when we execute a command in the shell?

The path

SSH's most notable applications are what?

Remote login, command line execution

Name one file transfer protocol based on SSH.

scp (secure copy), sftp (secure file transfer protocol), rsync

What is an administrator account?

Account to run commands as a root user

What type of account do users like Apache have?

Service accounts

What type of accounts belong to users like sys or a daemon?

System accounts

What file contains user information?

/etc/passwd

Where are user password hashes stored?

/etc/shadow

Where are local user configurations stored?

~/.bashrc

What restricts the rights and access of a user to the minimal amount required to perform their role?

Principle of least privilege

What element of user management says administrators of a system should not share accounts?

Individual accounts

What are some of the basics of password management?

Require the password to be changed periodically, do not allow the reuse of old passwords, require that they be of some level of complexity

SystemV has run levels, what did SystemD migrate to?

targets

In SystemV Linux what is the centralized configuration file?

/etc/inittab

What is rsyslog?

Improved faster syslog

What command is used for querying systemd for logs?

journalctl

What command is used to edit the crontab?

Crontab -e

What is each field of the crontab?

Minute, hour, day of the month, month of the year, day of week, script or command

What is the Debian package manager called?

apt

A package is a container for what?

Metadata

What command is used to check network connectivity?

Ping

What command is used to display the routing table?

route

What information do you need to configure an IP address?

IP address, network mask, default gateway

What are three command line tools used to interact with Networkd?

Networkctl, nmtui, nmcli

The d after a process name ie Networkd stands for what?

daemon

Samba’s functionality comes from what two protocols?

SMB & CIFS

What does Samba do?

Allows file and print sharing across OSs

Samba security modes are set in which file?

smb.conf

What are the two security modes in Samba?

User and shared

What protocol does LDAP sit on top of?

TCP/IP

What are two common implementations of LDAP?

Active Directory (AD) for Windows and OpenLDAP for Linux

The majority of Apache servers run on what system?

Linux

Where is the index.html file located?

/var/www/html

What are the symbols used to denote request and response headers?

'request' & < 'response'

What code means everything worked correctly?

200 OK