Basic Linux Tasks Flashcards
What is Kernel?
The kernel is the central core of Linux OS that manages all the computer’s physical devices
How to open multiple shell?
type bash to open bash shell and csh to open C shell
How to determine the current Shell?
echo $SHELL
How to navigate with |more
spacebar to view next full page, Enter to view line by line, b to go back and q to quite
What is head and tail commands?
Head displays the first 10 lines of each file and tail displays the last 10 lines of each line
What is Piping commands
It allows to pipe the output of one command to the next command for example ls|more
How to issue multiple commands
Use semicolon
What is exec command?
It kills the parent process which is the Bash and run the command as the parent process
What is the uptime command?
Displays the time from which the system started running, current time and how many users logged in
What is who command?
Used to determine the details of users currently logged in to a system
what is whoami
Used to determine which user you are currently logged in to the system
what is w command
Determin which user are logged in and what is their last transaction
what is last command
Displays the history of user login in and out
What is wall command
Send a message to all the logged in users
What is echo command
used to display a line of text on the terminal and to display the value stored in a variable
what is man command?
Used to display manual for a command
How to find which command is used to perform a certain action?
apropos
What is the command that displays a short description of the command along with the man page
whatis
what is a service on Linux?
is an application or set of applications that perform task in the background.
What is a deamon ?
It is a program that runs in the background without the need for human interaction. It lies dormant until an event triggers it.
What is the first process run on boot
Init
What is init responsible for
runlevel of the system
what is runlevel
Specifies the group of process that are started, stopped and managed on Linux system. Init scripts create process a system boot time from a script in the /etc/inittab file.
How can you change runlevel
using telinit command
What is Upstart Init Daemon?
It is event-based system rather than runlevel-based. Event based means that jobs will be automatically started and stopped by changes to the system state.
What environment variables that init daemon sets from the runlevel event
RunLevel and Prelevel
What is Systemd Init Daemon?
It is a replacement of SysVinit and Upstart in some Linux distribuiton. It allows for greater concurrency and reduces shell overhead. Control groups (cgroups) are used to track processes instead of PIDS
What command allows control over the Systemd Init process.
systemctl
Where would the boot loader choosen placed?
Master BootRecord (MBR)
What is the Linux boot loader that loads and starts the kernel
GRUB
what is a service on Linux?
is an application or set of applications that perform task in the background.
What is a deamon ?
It is a program that runs in the background without the need for human interaction. It lies dormant until an event triggers it.
What is the first process run on boot
Init
What is init responsible for
runlevel of the system
what is runlevel
Specifies the group of process that are started, stopped and managed on Linux system. Init scripts create process a system boot time from a script in the /etc/inittab file.
How can you change runlevel
using telinit command
What is Upstart Init Daemon?
It is event-based system rather than runlevel-based. Event based means that jobs will be automatically started and stopped by changes to the system state.
What environment variables that init daemon sets from the runlevel event
RunLevel and Prelevel
What is Systemd Init Daemon?
It is a replacement of SysVinit and Upstart in some Linux distribuiton. It allows for greater concurrency and reduces shell overhead. Control groups (cgroups) are used to track processes instead of PIDS
What command allows control over the Systemd Init process.
systemctl
Where would the boot loader choosen placed?
Master BootRecord (MBR)
What is the Linux boot loader that loads and starts the kernel
GRUB
What is cat
Concante files toghther such as cat filename1 filename2 > newfile
