managed to write a file from terminal input - Rust

My Text editor program in Rust programming language managed to get input characters from screen terminal as created a file once program ends.

Read the code here
https://github.com/davnav/RustEditor/blob/master/main.rs


If I started writing this in C, i would have end up in "Segmentation fault". But even though Rust compiler makes you learn the syntax and new concepts ( mutation,scope,borrow etc) . But once we managed to compile the code, the program produces the output as we expected.(won't go to the buffer overflows or pointer problems)

Terminal is not pointing to left most position when I hit enter, looks like I need to handle this manually.

I have not build any 'struct' for 'Editor' or 'Rows'. Not sure much syntax for 'struct' in Rust.  Reading more this now.


 I think I can move to the 'text viewer' pages in the below documentation.
https://viewsourcecode.org/snaptoken/kilo/04.aTextViewer.html

Finally refreshed the terminal screen

It was always a big question in me that all schooling/engineering  programming  courses( C or assembly)  teach Fibonacci series or some tough logic program ( something like for a given number 'N' search the subset bla bla .. ) . But when I looked at the computer , I wondered how they build these screens/commands and applications.. is it with Maths ?  is it with Fibonacci series /prime numbers? (They are not, it made up of simple logics.. but its like a 'building blocks' game)

My expectation from computer classes was  to build some screens or applications ,  ( but generally I got bored with theory . there was my fault too , i admit ) . Computer applications/commands  did not look like mathematical problem ,But computer subjects seems to me as  mathematics subject. ( I know they really need maths, when we deep dive).

But as a beginner, I misunderstood that someone who knows deep maths can only do something with computer .. but actually that is not the case.

Whatever programs I studied/taught to  do something with stdin ( standard input) or stdout( standard /the screen), are something like 'reverse string' or 'search character', but they did not generate any motivation to build some real world applications, rather I got scared even to attempt/read big programs, thinking it might require big logical algorithms that my brain can't digest.  but as student I always wanted to build something like 'vi' (editor) or some commands or something having windows (not Microsoft windows) screen. At least I wanted to know how these functionalities are coming in the screen.
When I build some functionality that actual 'vi' editor has , I feels like I am writing programs as a professional (Really its not the case)

Having said all these story :-)  as a hobby project , I am  trying to build an editor based on the documentation https://viewsourcecode.org/snaptoken/kilo/03.rawInputAndOutput.html

I am learning lot of things when I wanted my program to do some functionality that 'vi' editor does.

More over I am trying to build this in Rust language  which is a new generation  computer programming language , capable of replacing 'C' language. Every system programmers should try to learn it as per http://web.stanford.edu/class/cs140e/

:-)


My text editor draft , just refreshed the screen :-)
https://github.com/davnav/RustEditor



The clear screen functionality can be easily built with below code, but it was never known to me ( as I know only Fibonacci ... :-) )

// Refresh the screen by writing "x1b[2J" byte to screen
io::stdout().write(b"\x1b[2J");
println!();

// align the cursor to the left top by writing  "\x1b[H" byte to screen
io::stdout().write(b"\x1b[H");



but be aware , Rust compiler is ruthless :-) . it makes us read the documentation thoroughly.

do we need to take care 'String' type carefully ?

When I tried to do something with "Strings" in C programming language, either it won't give the desired result or I end up in 'Segmentation fault'. Lot of books in C show "Strings" manipulating with pointers. I like C in the sense  that we can access the characters with the memory where they sit. But when  I compile the full program, it compiles without any error , but finally  when I run it , normally I endup in "Segmentation fault".


So thought of learning some string manipulation/Methods in Rust Programming language.

https://doc.rust-lang.org/std/string/struct.String.html#method.from

Rust-lang learning continuation...

I tried to start again to read on the Rust-Lang tutorials . I thought , i can start with web development in Rust. Usually I directly jump to advanced side of a language and stop it in a few days :-).  Most of the languages I tried that way are ok to start, But Rust is a little more difficult .

For Rust , directly jumping to web development is really tough without understanding the basics. But I am not going to change that method.( really its like ,going back and forth )


Rocket is similar to Flask or Django .. but Rust syntax is killing me.. I can't blame Rust, as it is trying implement safe code.  Rust compiler is so rude, seems like  it won't allow me to compile a single program :-)

Todays learning:

&'static str

"This basically reads as "a reference to a string slice with the lifetime of static", which means that the string has a lifetime of the global scope"

& is familar symbol for programmers, it is used to reference a variable. Generally to get the address of variable .

just refreshed here - https://www.cs.fsu.edu/~myers/c++/notes/references.html

But what is  ' symbol , this is something new to me. it is the lifetime. other programming languages have the scope of the variable. But those languages compilers are not always smart enough to understand the scope of the variables or in other words Rust-lang push to define the life time of the variables for each functions. ( From this, I hope compiler can do the garbage collection by itself)

read more: https://www.quora.com/What-is-the-meaning-of-in-Rust

Crates and Modules in Rust Language

I was trying to jump into Rust programming language through Rocket web framework. I know it might be a tough attend to directly start with Rocket without much understanding on the Rust syntax.

I believe I have a minimum understanding on Rust syntax and I thought let learn it reverse way , whenever something comes strange or unknown ,let go reverse and goto the basics.

 So, with that strategy when I jump to Rocket , I came across lot of new things.. Ofcourse Rust has lot of new syntax , terminologies. But since I had some prior knowledge on Flask,Django web frameworks, I did not stunt by the folder structures and initial quick start steps.

but it is really fun learning it in reverse way, lot of new things to understand.

One thing was Crates and Modules. It not a new idea, but it a new term and building it in Rust is quite easy.

We have a good documentation from these from Rust developers.

As per my understanding,

If you know python, we will be using packages there. Similar way we can use Crates to build modules and import them into our program.

I hope below documentation will be enough to read through it and try it.

https://doc.rust-lang.org/book/first-edition/crates-and-modules.html

https://rustbyexample.com/attribute/crate.html

Books reading as a Hobby

First of all, I haven't read any book completely apart from normal curricular. But I read online computer articles and blogs very seriously last a few years. I am finding it as a brain taking process.But its worth reading those technical articles and understanding them. Mostly I follow youtube, I need some demo to start with something rather than just reading and understanding.

I don't know I need take other books like literature,fiction,philosophy as well or stick with (focus) more on the technical stuff alone. I bit confused , but i believe now its essential for me to start reading some other(non technical books) as well ( because not sure how to spend time).

But I know, diverting the focus from technical articles and blogs will be disaster for me.

Lawrence Krauss - Physics Made Easy

Plot multiple Coins prices in Single graph using Python Mathplotlib

How to use Mathplotlib for plotting multiple graphs:

https://steemit.com/steem-dev/@naveendavisv/plot-bitcoin-and-ethereum-price-graph-using-python-mathplotlib-program

Python program to read bitcoin price and plot as a graph

How to plot bitcoin price using Mathplotlib + mysql

This program is explained in the below link .https://steemit.com/python/@naveendavisv/bitcoin-price-graph-plot-with-python-program-mysql

How to publish top 10 hot posts from steemit using python program

Its very interedting play with data steemit blockchain provides

https://steemit.com/steem-dev/@naveendavisv/5-how-to-steemit-application-with-pistion-and-flask-python-programming-modules

How to get the Steemit 'followers' for an account using Python Piston module

You can get steemit followers using python program.This is fun and learning experience to understand steemit and blockchain. Read more technical details here. https://steemit.com/steemit-dev/@naveendavisv/4-how-to-build-steemit-applications-with-piston-python-module

How to build applications for steemit with Python programming?

You can do some application for steemit using python
Read the details here

https://steemit.com/steemit/@naveendavisv/2-how-to-build-applications-for-steemit-with-python-programming

Bitcoin/crypto currency JSON format data extract using python programming

This progarm we try to extract the data on every 15min from https://coinmarketcap.com/api/  to mysql database using python program.

How to get bitcoin json data using python

1.https://coinmarketcap.com/api/
Get the api details
2. create a python program


json object format:




Bitcoinurl.py

3. create table in mysql

if you need to know more about mysql go through https://dev.mysql.com/doc/refman/5.7/en/creating-tables.html

4.crontab to schedule every 15min. You have to identify user python program location and give

Watch the video tutorial below.