Linux basic commands for oracle dba juniors

  The contents are of my own testing and deployments. Not guaranteed that these might work in your environment. Please test before usage.


Summary: I will teach basic LINUX Commands for juniors in oracle dba in this session

The command-line interface is one of nearly all well-built trademarks of Linux. There exists an ocean of Linux commands, permitting you to do nearly everything you can be under the impression of doing on your Linux operating system. Although, this to the end of time creates a problem: with all so copious commands accessible to manage, you don't comprehend where and at which point to fly learning them, especially when you are a learner. If you are facing this problem, and are peering for a painless method to begin your command line journey in Linux, you've come to the right place, as in this, we will launch you to a hold of well-liked and helpful Linux commands.

Description: 

Display system date and time.

Command: 

date

OP:



Description: 

Display calendar

Command: 

cal 

OutPut:



Description: 

Display date, time and calendar

Command: 

date & cal

OutPut:



Description: 

Used to clear the terminal window. 

Command: 

clear

OutPut:

Clean the all texts in that terminal

Description: 

Display free and used system memory.

Command: 

free 

OutPut:



Description: 

Display free and used system memory in bytes

Command: 

free -b

OutPut:



Description: 

Display free and used system memory in kilobytes

Command: 

free -k 

OutPut:



Description: 

Display free and used system memory in megabytes.

Command: 

free -m 

OutPut:



Description: 

Change user password.

Command: 

passwd 

OutPut:



Description: 

Reveals your command history

Command: 

history

OutPut:



Description: 

Display the IP address of the host

Command: 

ip address

OutPut:

     


Description: 

List the size of files and directories

Command: 

ls -s

OutPut:



Description: 

View mounted file systems.

Command: 

mount

OutPut:



Description: 

Display the information of disk usage of files and directories.

Command: 

du

OutPut:



Description: 

Tells you how long the system has been running

Command: 

uptime

OutPut:



Description: 

View and change the configuration of the network interfaces on the system.

Command: 

ifconfig 

OutPut:



Description: 

Lists all files and directories in the present working directory

Command: 

ls

OutPut:



Description: 

Display disk usage

Command: 

df 

OutPut:



Description: 

Provides a quick overview of the currently running processes.

kill Command: 

top

OutPut:



Description: 

The system performs an immediate reboot.

Command: 

reboot 

OutPut:

Description: 

Terminate processes without having to log out or reboot.

Command: 

kill -9 (process id)

OutPut:

Description: 

Change the current working directory

Command: 

cd 

OutPut:

Description: 

List open files

Command: 

lsof 

OutPut:



Description: 

List USB devices

Command: 

lsusb

OutPut:



Description: 

Display the current directory.

Command: 

pwd

OutPut:



Description: 

Displays CPU architecture information (such as number of CPUs, threads, cores, sockets, and more).

Command: 

lscpu

OutPut:



Description: 

Displays the number of processing units available to the current process.

Command: 

nproc

OutPut:

[oracle@rac1 app]$ nproc

4

[oracle@rac1 app]$


Description: 

List files by date.

Command: 

ls -lrt 

OutPut:



Description: 

Report information about storage devices such as hard disks, flash drives etc. 

Command: 

lsblk 

OutPut:



Description: 

Prints current year's calendar.

Command: 

cal -y 

OutPut:



Description: 

Displays information about running processes in the form of a tree.

Command: 

pstree 

OutPut:



Description: 

Displays the size of each individual file

Command: 

du a

OutPut:



Description: 

Takes you to the previous directory.

Command: 

cd - 

OutPut:



Description: 

Lists your last logins.

Command: 

last yourusername 

OutPut:



Description: 

Create a new directory called myfiles

Command: 

mkdir (filename)

OutPut:



Description: 

Remove the directory myfiles.

Command: 

rmdir filename

OutPut:



Description: 

Creates a user "root1"

Command: 

useradd "root1"

OutPut:

Description: 

Assign password to user "root1".

Command: 

passwd "root1" 

OutPut:

Description: 

Repeats the last command.

Command: 

!!

OutPut:



Description: 

Display Who you are logged in as

Command: 

whoami 

OutPut:



Description: 

Print the kernel version.

Command: 

uname -v

OutPut:



Description: 

Print the operating system.

Command: 

uname -o 

OutPut:



Description: 

Report the machine hardware name.

Command: 

uname -m 

OutPut:



Description: 

Display all the active interfaces details

Command: 

ifconfig

OutPut:



Description: 

Create a empty file (test.txt).

Command: 

touch test.txt 

OutPut:



Description: 

Print the last 10 lines of a file (1.txt).

Command: 

tail 1.txt

OutPut:

Description: 

Display host's numeric ID in hexadecimal format.

Command:

hostid 

OutPut:



Description: 

Display IP address of the hostname

Command: 

hostname -i 

OutPut:



Description: 

Check the network connectivity between host (your connection) and server (Google server). 

Command: 

ping google.com


                                                    Thanks for your time !!!


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