DEV Community: Priyadarshini Chettiar

Some important Linux Commands for Devops

Priyadarshini Chettiar — Fri, 29 Jul 2022 14:40:56 +0000

Today I'm going to share some of the important linux commands that you will be using as a Devops Engineer

So, lets get started

cat /etc/os-release -> To get the OS details (eg. name,version etc)
ps aux | grep "process_name" -> To get the process owner details ( eg. ps aux | grep "jenkins" )
cut -d: -f1 /etc/passwd -> To get the all the users list
lsblk -> To get all the list of block devices mapping
df -h -> To get the filesystem details
uname -a-> To get the OS name, machine name and kernal
wget https://... -> To download files from the web.
ifconfig -> To check the network interfaces
netstat -a -> To list all network ports, routing tables, sockets and connection details
apt list --installed -> To check the installed packages ( eg. apt list apache2 -> To check apache2 related packages)
apt list | grep nginx -> To check if ngnix is installed
dpkg --list | grep nginx -> To check the installed packages
cat /etc/services | less -> To check the open ports
netstat -atu -> To check the open tcp ports
netstat -lntup -> To check the open tcp as well as udp ports that are listening along with their process ids
lsof -i 4 -a -p <Process-Number> -> for listing open files related to processes ( 4 implies ipv4, -a is used for Anding the output, -p is used to specify the process id we wish to check)

Unix Time in Flutter

Priyadarshini Chettiar — Wed, 09 Jun 2021 20:04:51 +0000

I had the privilege to work for an organization and develop a flutter application which communicates with an IoT Device. While developing the application, I was asked to use Unix Time, which otherwise called as Epoch Time.

My research taught me that

"Unix time is a system for describing a point in time. It is the number of seconds that have elapsed since the Unix epoch, minus leap seconds; the Unix epoch is 00:00:00 UTC on 1 January 1970; leap seconds are ignored, with a leap second having the same Unix time as the second before it, and every day is treated as if it contains exactly 86400 seconds" - source Wikipedia.

So, how do we implement it in Flutter using Dart?

Well the answer is pretty straight forward, we have inbuilt functions in dart to do the required.



void main(){
DateTime now = DateTime.now();
var epochTime= now.millisecondsSinceEpoch;
print(epochTime);
}

The output we get after the above would be in milliseconds i.e. there will be 13 digits and in decimal format.

If you need the output in seconds then , just divide the output by 1000, to fix it to 10 digits



DateTime now = DateTime.now();
var epochTime= now.millisecondsSinceEpoch/1000;

certainly can use floor, ceil and round methods if required to refractor the above values.



void main(){
DateTime now = DateTime.now();
var epochTime= (now.millisecondsSinceEpoch)/1000;
var testFloor= epochTime.floor();
var testCeil = epochTime.ceil();
var testRound = epochTime.round();
print(epochTime);
print("Testing Floor - " +  testFloor.toString());
print("Testing Ceil - " +  testCeil.toString());
print("Testing Round - " +  testRound.toString());
}

In case you need the value in microseconds, use the microsecondsSinceEpoch function.



void main(){
DateTime now = DateTime.now();
var epochTime= now.microsecondsSinceEpoch;
print(epochTime);
}

Now, what if you want the value in different formats like HexCode or Binary or Decimal

Well though it sounds little complicated its simple using the toRadixString() function.

To convert the time value into Binary you need to pass the parameter "2" to the above function.
To convert the time value into Decimal code you need to pass the parameter "10" to the above function.
To convert the time value into Hexadecimal code you need to pass the parameter "16" to the above function.



void main(){

// assign the output in decimal format and in seconds
var epochTime= (DateTime.now().millisecondsSinceEpoch)/1000;

//Using Floor methid to get absolute value
var convertToFloor = epochTime.floor();


//convert the value to Binary
var convertToBinary= convertToFloor.toRadixString(2); 

//convert the value to Decimal
var convertToDecimal= convertToFloor.toRadixString(10);

//convert the value to Hex Code
var convertToHex= convertToFloor.toRadixString(16);

//print all
print("The Epoch Time in seconds is "+ epochTime.toString());
print("Using Floor to get absolute value " + convertToFloor.toString());
print("Converted to Binary - " + convertToBinary);
print("Converted to Decimal - " + convertToDecimal);
print("Converted to Hex - " + convertToHex);
}

That's it for this article, hope you found this article helpful.

Though its simple, I would like to know your thoughts in comments.

Until we meet again with my next article, Happy Coding 😃

My first hackathon - MLH LHD- Build 2021

Priyadarshini Chettiar — Fri, 15 Jan 2021 16:26:08 +0000

What is MLH LHD Build?🤔

Well it is Major League Hacking - Local Hack Day Build.
Major League Hacking is the Organization and Local Hack Day - Build is the name of the hackathon event.

About the event✨

It started on 10th Jan 2021 and will end on 18th Jan 2021.
This is my first ever hackathon. I was nervous for this event due to imposter syndrome, but its going pretty well.

There were daily challenges and weeklong challenges.
They are beginner friendly and there are many workshops to enhance our skills and knowledge.

Takeaways🤩

I personally developed some amazing apps in Flutter like sending sms using twilio, chess app, tic tac toe, translator, speech recognition app, working with data sets and many more.

This event has made my profile strong and I'm very confident about attending more hackathons in future.

The workshops conducted at MLH are best, the instructors/ coaches are incredible. The coaches Jackyln, Ryan + Totally Not Ryan 😉, Mary, Mara, Chris, Will, Shasrika , Kunal, Aditya to name a few, I'm really thankful to them.🤗

I repeat they are the best!

I finally created my portfolio using Github pages, thanks to the coaches.🎉🥳

Do you know the best part of these challenges?

Learning never felt so good

Apart from challenges we had many games to play, draw Ellie elephant, Bob Ross and Bhlahaj, cupstaking and many more.

I just loved it.❤

Though there were points for completing each challenge, I personally focused on learning the concepts and trying it out.

I'm sure that I'm going to participate in all the future events by MLH. Well, MLH Share is on the way - in April. I would recommend the developers at every level to give it a try. You would definitely love it, thank me later!

Did I shared about prizes?

We will get swags and stickers from MLH. Can't wait to get mine.😄

Author: Priyadarshini Chettiar