Tech Info Talks

Difference between val and var in scala

2017-07-27T23:13:00.000-07:00

val and var are two ways of declaring variables in Scala. val is immutable means it cannot be changed once declared.

var is mutable means it can be changed at a later point of time in the program .

Jeff Bezos became worlds richest man

2017-07-27T11:00:00.001-07:00

Amazon's CEO Jeff Bezos became world richest person pushing Microsoft Chairman Bill Gates to next.

Scala

2017-07-25T09:15:00.001-07:00

Scala is a object oriented functional type programing language. All variables declared in scala is considered as objects.

Game of thrones season 7

2017-07-16T10:27:00.001-07:00

Game of thrones season 7 will start from tomorrow July 18th .

Try it online --TIO

2017-07-16T07:28:00.001-07:00

Recently I came to know about a site TIO.run . It has almost 97 languages compilers which help you to code and execute. I find it very cool since you don't need to install anythin to try out in your computer , instead write and compile it online. Try tio.run

How to enable developer mode in android?

2017-07-16T07:17:00.001-07:00

To activate developer mode in Android , go to Settings > About phone . There you can see Build Number. Tap the option 7 times then developer mode will be activated. Now enjoy deploying the app you develop in Android Studio into the phone instead of creating virtual device in the IDE.

Primitive datatypes in hive

2017-07-09T07:39:00.001-07:00

String data types

STRING
VARCHAR
CHAR

TINYINT
SMALLINT
INT
BIGINT
FLOAT
DOUBLE
DECIMAL
BOOLEAN

TIMESTAMP
DATE

Complex datatypes in hive

2017-07-09T07:36:00.001-07:00

The following are the main complex data types in hive

ARRAYS
MAPS
STRUCT
UNION

Hive version

2017-07-08T22:36:00.003-07:00

To check the hive version from command prompt use the command.

$hive --version
Hive 1.1.0

Advancement in analytics

2017-06-30T07:27:00.001-07:00

Today I decided to sell my samsung monitor which I got 10 months back. It is having a vga port, which I cannot connect to my HDMI port laptop. I have decided to post in OLX.
I downloaded the OLX app and as soon as it was open the camera icon came to take the picture of the item we need to sell. I took two pictures and was then searching for the category of the item to select. I only could find the option as 'other items'.To my surprise the title of the ad came automatically - Samsung flat screen monitor'. I did not even gave any other options everything what I need to say about the item was there including company name and also flat type(Only the screen size I had to give later).

From the picture I took , they identified the type of object. Since the company name Samsung logo was present in the front of the screen it identified that and formed the title. What should I give more than these!.

The image identification and analysis have grown so much that how easy it is made to ease our work. Thank to analytics and machine learning.

Jelly effect in one plus 5

2017-06-29T11:47:00.001-07:00

One plus 5 is the latest one among the one plus series.Within a week of its cool launch users are coming up with minor issues in it. Some users are seeing jelly scroll effect - letters or images getting stretched when scrolling slowly on the screen.

Apart from these the phone is cool and competing against it's peers Samsung Galaxy S8 and iPhone .

How to get IMEI number of my phone?

2017-06-29T09:20:00.002-07:00

To view the IMEI number of the phone dial #*06#. This will display the IMEI number.
If your are using a dual sim phone then 2 IMEI numbers will be displayed each for a SIM.

Pattern lock in android

2017-06-27T22:21:00.001-07:00

To add a pattern lock in android phone follow the below steps.

1) Open the Setting from the app list. Choose the option Security from the list

2) Select Screen lock from the page apperaring

3) Then we need to given the pattern which we need to use to lock or unlock the phone.Simply swipe along the dots with your finger.

Python : Swap two numbers

2017-06-13T01:12:00.000-07:00

This is the easy and coolest way to swap two numbers in python,

a = 0
b = 1
print a,b
#output 0 1
> 0
#One liner code to swap two numbers
a,b = b,a
print a,b
#output 1 0

xargs in unix

2017-06-12T23:34:00.000-07:00

Sometimes we have a list with which we may need to do the same action on it. In such cases xargs command is very useful in unix.

Some scenarios:

Get word count of the files in a file

> ls | xargs wc -l

mutt command in UNIX

2017-06-12T23:21:00.002-07:00

To send mail from UNIX terminal we can use mutt utility.

Syntax :

> echo " Some text " | mutt -a <Any attachment> -s "Subject line" -- email-address

Example :

> echo "Wish you happy birthday" | mutt -a "gift.jpg" -S "Happy birthday" -- techmail@techinfotalks.com

SSH in unix

2017-06-12T23:15:00.002-07:00

To access another server/machine we use ssh to authenticate and do communication.

Syntax :
>ssh user@server -P password

This will login to another machine from our local system.

Sometime we may need to fetch the content from another file in remote system , in this case we can use the below form

>ssh user@server -P password "cat /home/abc/1.txt | grep <Text to search>"

If we echo the above we can see the content from our system

Eg :

echo $(ssh user@server -P password "cat /home/abc/1.txt | grep MMDDYYYY")

This will fetch the line with the date format specified from the file.

SCP command in UNIX

2017-06-12T22:50:00.004-07:00

To use scp command to transfer a file to another server use the below syntax

>scp <filename> <Target server>:<location>

Example:

>scp abc.txt ab-server:/home/abc/

Nokia android phones

2017-06-11T21:15:00.001-07:00

Nokia has launched Android phones in India. The official launch is on June 13th 2017. It comes in 3 variants . Nokia 3 , 5 and 6. The price of the phone is also leaked before it's launch. Nokia 3 will cost Rs. 9990, 5 for Rs. 12990 and 6 variant costs Rs. 15990 in India.

Nokia was one of the favourite brand during the first decard of 21st century. It lists it's shine with the launch of Apple iPhone and the subsequent growth smart phone industry with Android. Though it's late many are waiting for the Nokia Android phones launch.

Hadoop for beginners

2017-06-11T11:24:00.001-07:00

I just completed by hadoop fundamentals course from Udemy.com . The videos were very well organized so that you will get the glance of what is this world of big data and how hadoop framework can play a major role is processing this big data. The course was insisting in downloading hortonworks hadoop development sandbox and working with it. Hortonworks are providing the hadoop environment setup to download and we can load it in a virtual machine. I have downloaded the virtual box sandbox file.

The course gave a string insight on hadoop architecture and buzz words around it. It gave a in depth idea of hive and pig tools and how they play the key role in storing and processing data in the framework.

Python : String functions

2017-06-10T00:46:00.000-07:00

Hi all , I will show how to use some string related function and operations on list datastructure in python

String function

Length of string

len(string) - > This will bring the length of the string passed to it.

Check if a character in string is upper case of lower case

string[i].isupper() - > This is for checking upper case
sttring[i].islower() - > this is for checking lower case

Convert a character to upper case or lower case

a = string[i].upper() - > This is for converting a character to upper case
a = string[i].lower() - > This is for converting a character to lower case

Please note here i means the index of the character in the string.

Split a line of words

k = string.split(" ")

Here the string is split and words a assigned to a list. The delimited used is " "

List operations

Initialize as list

K = []

This will initialize a list

Add or append a value to list

k.append("a") - > This will add character a to list K.

Install sublime editor

2017-06-08T07:34:00.001-07:00

Hi. Sublime editor is a light weight editor and very helpful for developers to write code.It will highlight the code in colors for easy readability. Sublime editor 3 is the latest one available as of now . The below link shows how to install sublime editor in CentOS .

http://software-engineer.gatsbylee.com/how-to-install-sublime-3-on-centos-7-rhel-7/

To know about you system OS is 32 bit or 64 bit , use the below command.

>uname -a

basename and dirname

2017-06-08T00:23:00.002-07:00

basename

basename is a command used to get the filename or the leaf directory name from a path given. basically it will select the last string which is prefixed by /.

For example:

>basename /x/y/z/abc.txt
abc.txt

The above command will bring output as abc.txt

>basename /x/y/z/
z

It will bring z as output

Please note , inside a script if we use basename $0 , it will bring the name of the script. It has many uses.

dirname

dirname will bring the path of the directory. ie the prefix for / for a leave directory name or file.

For example:

>dirname /x/y/z/abc.txt
/x/y/z

The above command will bring output as /x/y/z

>dirname /x/y/z/
/x/y

It will bring /x/y as output

Alias command in UNIX

2017-06-07T23:37:00.001-07:00

Alias is used for creating alternative names for commands which have got long text as syntax. Also for commands which are very frequently used we can create alias with short letters so , can save some time in typing and getting result.

How to create alias?

alias ALIAS_NAME='COMMAND'

For example :

alias ll='ls -ltra'

So now when we give ll , the result showing will be same as ls -ltra command.

Another example :

alias s='df -h'

This will show the disk free space in the system.

How to view all alias created?

If we simply type 'alias' from the command prompt it will display all the alias created in the system.

Another point to note is , creating an alias will be available in environment level for the particular session only. It is similar to creating a variable. When we close the session the alias is also removed. Usually we keep the alias in .profile file in the home directory, so that every time when we open a UNIX session the alias variables are also assigned and we can use it easily.

How to buy stocks online

2017-06-04T03:01:00.001-07:00

Stocks or shares are all time favorite of anyone for wealth creation. You can buy a a stock of a company which is publicly traded from BSE - Bombay stock exchange or NSE - National Stock Exchange. They are basically two markets where stocks are listed for buying or selling.

Next is you should have a broker to dot the trades. If you wish to do online trading you need to have a demat account opened . Almost all banks and brokerage firms provide facility to open demat account with them. Each will follow there own brokerage charges.