DEV Community: AakritiGoyal12458

How to FIND, REMOVE and INSTALL A PACKAGE in RHEL8

AakritiGoyal12458 — Mon, 01 May 2023 19:05:00 +0000

95% of the commands we use in any OS are created by the software's/Packages. For Example, if we talk about Red Hat Linux Operating System: below we can see which date which cal
Here we run rpm -q -f /usr/bin/date
In simple words the command means red hat package management i have a query who created this file /usr/bin/date
and in return it will provide you with a software name.So let's start our demo by 1st finding Firefox package, let's run and check if it exists or not.Now,

Find Firefox package rpm -q firefox
Remove the package using rpm -e firefox check if firefox is installed
try to install firefox rpm -i firefox OOPS! WE ENCOUNTER AN ERROR No such file this means we cannot install Firefox like this. When we downloaded RHEL8 we had one DVD or iso file downloaded with us which is basically a bootable image. We will use this image as it already has 5k+ software in it. So, add the image in the optical drive. for that 1st soft shut down the system using init 0. now go to Settings ->Storage->Add Optical drive -->Add the pre installed iso imageas shown below After Inserting DVD, you will face 2 options regarding reinstalling the OS. but as you already have OS installed so to avoid this go to Settings ->System ->Boot Order and change it to hard drive and then optical drive. So, from now onwards if according to boot order if OS already exist in Hard Disk no option to reinstall will be shown and if OS do not exist in Hard Disk, then only install from DVD option will be shown. Now you can find DVD in GUI after going to Activities. All the Packages are stored in AppStream and BaseOs . NOTE: they all have extension as _.rpm _ Right click in white space: click on open in Terminal option you will be landed directly in DVD folder. Now our plan is to install Firefox. lets install Firefox using rpm -i firefox...(click TAB to get the full name at your terminal ) let's check if software is installed using rpm -q firefox. Thank You.

WHY OS and WHAT is OS :)

AakritiGoyal12458 — Tue, 28 Feb 2023 19:59:30 +0000

WHAT is an operating system ??

OS is made up of System Software .
OS is a piece of software that manages all the resources of a computer system ,both hardware and software.
OS provides an environment in which the user can execute his/her programs in a convenient and efficient manner .
Other than this OS acts as an interface between user and computer H/W by helping user to Access computer H/W . And It hides complexity of H/W.

How to launch Linux OS from EC2-instance as GUI ?

AakritiGoyal12458 — Tue, 21 Feb 2023 18:03:51 +0000

Companies using AWS

AakritiGoyal12458 — Sun, 19 Feb 2023 18:22:40 +0000

What is AWS?
Amazon Web Services (AWS) is a cloud service provider that uses Amazon’s own infrastructure and experience. Rather than a division of the company, like Microsoft’s Azure, AWS is a subsidiary company of Amazon.

AWS offers a wide range of cloud services, from basic hosting and deployment to analytics, blockchain, machine learning, and more.

Organizations of all sizes across all industries are transforming their businesses and delivering on their missions every day using AWS.

BigBasket Grows Bigger with 400,000 Daily Orders on AWS :
BigBasket, India’s largest online grocery, has been in business since 2011. Customer retention is at the heart of its strategy, as well as a hyper-local approach to inventory. BigBasket is available in 21 cities and runs its infrastructure on the Amazon Web Services (AWS) Cloud. The business had been growing 20–30 percent each year, but when COVID-19 struck and India went into lockdown, BigBasket faced unprecedented demand. Daily traffic was suddenly six times higher than pre–COVID-19 peaks.

Scales from 250,000 to 400,000 daily orders in 8 months
Maintains 99.9% site uptime with latency of 350 milliseconds
Saves 1 weeks’ worth of staff time per month on database maintenance
Frees up engineering time with managed services
Recommends products to expedite shopping experience
Develops loyalty program to reward repeat shoppers
Achieves high degree of geo-segmentation with data tools

INTERACTING WITH SERVICES PROVIDED BY AWS

AakritiGoyal12458 — Thu, 26 Jan 2023 07:21:38 +0000

For interaction services provided by AWS we have various ways :

Web UI
CLI
API
Cloud Formation

First 3 approaches are Monotonous and harder in terms of Management .

For Example , in CLI we have scripted or Imperative approach where we have to tell

What to do
How to do

but Approach 4 is Declarative Approach where we only have to tell

What to do

AWS has its own tool service called as CLOUD FORMATION that help us with Automation and is declarative.

Creating HTML Anchor Tag With JAVASCRIPT

AakritiGoyal12458 — Mon, 01 Aug 2022 19:36:31 +0000

This article will help you to create link over any text you have used in your webpage without using anchor tags of html .

Also whenever you will click on link it will ask you to confirm whether you want to continue or not ...

Step 1

We know Browser know our current workspace and JavaScript is the best way to communicate with browser . So with this command
document.location="delete_me.html" JavaScript can ask for your current location from Browser .

Step 2

We have confirm dialog box in JS confirm()which gives its o/p as Boolean values . These values can be used with if and else conditions .

Code:

<script>
function abc(){

var c= confirm("Do you want to Continue....?? ");

if(c)
     {
          document.location="delete_me.html";
     }
else
     {
          alert("we stay here");
     }

}
</script>

<body>
<div onclick=abc()>Click me </div> 
</body>

AakritiGoyal12458 — Thu, 25 Nov 2021 12:52:36 +0000

Points you should definitely keep in mind while creating a LinkedIn profile .

Customize:
- LinkedIn URL
- Name , tagline , note(message)
- Profile picture
- Relevant title
- Headline
How your profile pic should look like
- A headshot pic
- With smile on face
- Formal dress up
- A clear background
- A high-quality picture
Add Skill Sets
Be approachable
- Add email-id
- Contact info
- About section
Add summary
How to Use the featured snippet
Boost credibility :
- Get recommendation
- quality quantity and right people matters e.g. College professors colleagues’ client HOD current and managers
- take recommendation from the people who are relevant to your field
- you should focus on your hard skills and soft skills.
You should add around 10 second voice note to your profile with
Approachable cover story
The three E’s approach i.e.
- Education
- Experience
- Endorsement
BYA approach i.e. Boost Your accomplishment : By adding a Publication ,patent, courses, project ,test scores, languages, Organisation , Honours and Awards.

espeak -ng

AakritiGoyal12458 — Wed, 29 Sep 2021 18:07:23 +0000

date | espeak-ng
it speaks date
espeak-ng — version
it shows version
espeak-ng -v hi+f2 -q “text”
it speaks silently we won’t hear anything
espeak-ng “hello Everyone”
speaks the text written in double quotes
espeak-ng -a 200 “hello world”
speaks text with amplitude of 200
espeak-ng -g 100ms “hello world”
speaks the words with the gap of 100 ms
espeak-ng -k 1 “hello world”
speaks the text with sound with each word
espeak-ng -k 2 “hello world”
speaks capital with each words it speaks
espeak-ng -k 200 “hello world”
if we increase the value with -k option it increase the pitch of text
espeak-ng -p 200 “hello world”
we set a pitch (value of p depend on your choice)
espeak-ng -s 200 “text”
it speaks words with a speed of 200 words per minute(value depend on your choice)
espeak-ng -v af+f2 “text”
it speaks with aferican accent with female voice
espeak-ng -v hi+f2 “text”
it speaks with hindi accent with female voice

Fun Commands In Linux

AakritiGoyal12458 — Wed, 29 Sep 2021 17:55:52 +0000

Fun Commands In Linux

1, sl/LS
2.Fortune
3.rev
4.Factor
factor 34568
5.cowsay
cowsay Hello Friend

fortune | cowsay

'|' is called pipeline instruction and it is used where the output of one command needs to be the input of another command. In the above example, the output of the 'fortune' command acts as an input of the 'cowsay' command.
6.xcowsway
xcowsay I Love Linux
7.cowthink
cowthink Linux is sooo funny

Yes yes Linux is funny

This command will run to infinite until you interrupt with "left ctrl+c"

figlet HELLO
pi pi 25
cmatrix cmatrix cmatrix -h

Date Command in Linux

AakritiGoyal12458 — Wed, 29 Sep 2021 17:25:44 +0000

Date command in Linux

date command is used to display both date and time in Linux .
you can format date and time by using this command

In Terminal

date
man date : this command will open date manual

using some command

date -d "STRING"

date -d "now"
date -d "today"
date -d "yesterday"
date -d "tomorrow"
date -d "1 hour ago" // no.of hour and then add ago keyword
date -d "1 hour " //to check future timming do not add ago keyword.
date -d "2 years 3 months and 1 day"
date -d "2 years 3 months and 1 day ago "

now, lets set the time

date -s "STRING"
date utc --universal time

date-u

trying various formats with date command

syntax== date +%FORMAT

tip--you can simply type man date to see commands no need to learn them

lets go through some examples
1.date +%r //to see only time
2.date +%D //to see only date
3.date +%d%m%y //to see date in format you want
4.date +%d/%m/%y //use "/" for cleanliness
5.date +%d/%m/%Y //"Y" to display year in 4 digit
6.date +%d/%b/%Y //b used to display month in 3 leter eg. September as Sep
7.date +"%d %b %Y" //to use spaces you have to make sure to enclose between double inverted quotes.
8.date +"%a %d %b %Y" //%a for days in 3 letters eg. monday as mon
9.date +"%A %d % b %Y" //%A for full day name eg. monday as MONDAY only
10.date +"%A %-d %-m %Y" //using "-" removes 0 from the single digit number .
11.date +"%A %-d %-m %H %M %S" // hours , min and seconds
12.date +"%A %-d %-m %I %M %S" //12 hour format
13.date +"%A %-d %-m %I %M %S %p"// to display time in AM

similarly you can try more commands .

Zenity Command in LINUX

AakritiGoyal12458 — Mon, 27 Sep 2021 19:50:04 +0000

If you want to print something as a pop-up on your screen or you can call it as GUI (graphical user interface) we have a lot of dialog boxes .
GTK is a graphical tool in Linux like qGUI .

Commands

zenity --version
man zenity
q to quit

zenity --calender

zenity --entry : to take input from the user

To see manual we have 2 options

man zenity
zenity --help

In zenity whatever you type should be stored somewhere.

zenity --entry now ,lets store the data

eg . x=zenity --entry
this is a wrong way to store the data

Correct way :
x=$(zenity --entry)
(💡: No space before and after equal in shell scripting)
echo $x

zenity --info

zenity --info --text="Hey Aakriti this side"

For more commands you can explore with the help of zenity manual .