Forem: 5hfT

I built a VS Code extension to see what Claude Code is actually doing across all my projects

5hfT — Sun, 15 Mar 2026 17:36:03 +0000

If you use Claude Code heavily across multiple repos, you probably know this feeling.

You have Claude running in several projects at the same time and at some point you start wondering:

How much did I spend this week?
Which project burned the most tokens?
What was that session from yesterday even about?

I kept hitting this problem, so I built a small tool for it.

It's a VS Code extension called Claude Code Dashboard that shows everything Claude Code has been doing across your projects in one place.

Main features:

🗂️ See all Claude Code projects in one sidebar
📝 Session history per project (shows the first prompt as preview)
💰 Token and cost breakdown per session and per project
📁 See which files Claude touched and which tools it used
⚡ Detects when a Claude session is actively running

The nice part: there’s no setup.

No API keys, no accounts, nothing external.

It just reads the session data Claude Code already stores locally.

I mainly built it because once you start using Claude Code a lot, you lose visibility pretty quickly.

Available here:

Promo Homepage: https://claude-code-dashboard-jspw.vercel.app

VS Code Marketplace: https://marketplace.visualstudio.com/items?itemName=jspw.claude-code-dashboard

Open VSX (Cursor / Windsurf) -> https://open-vsx.org/extension/jspw/claude-code-dashboard

Source Code -> https://github.com/jspw/Claude-Code-Dashboard

It's free and open source (AGPL-3.0).

If you're a heavy Claude Code user, I'm curious if this would actually be useful for you or if there are other things you'd want to see in a dashboard like this.

Cool, Fancy & Cutting Edge Shits I have Learnt Recently

5hfT — Tue, 26 Nov 2024 05:23:05 +0000

mixing Legacy MVC (WEB) Framework & Modern Frontend Framework/Library (Springboot MVC X JSP X ReactJs)
Using Multiple (3) Databases in a single application
Using Two Mongodb databases in a same application
Using Multiple (2) Apache ActiveMQs (not multiple Queues obviously) in a single application
Running multiple instances of a single expressjs/nodejs application with statically defined docker-compose files

The Weird Javascript

5hfT — Thu, 07 Oct 2021 06:09:34 +0000

This is Mehedi Hasan Shifat. I am trying to write about the things I feel weird about javascript (not saying bad :3). i will write something about javascript everyday whenever I get some free time. Mark watch The-Weird-Javascript to get latest update.

Note : This is not a blog/article/repo to learn javascript. you can get some awesome blogs and video playlists about javascript which are really awesome. And feel free to correct me.

Contents
- Undefined | Error ?(being written )
- Betrayal of Switch-Case(to be added)
- Reference in Javascript(to be added)
- Type(to be added)

Undefined || Error ?

Let's look at some code snippets.

code-01

console.log(num);
num = 10;
var num;

Guess, what is the output of the code ?
Is it a compilation error ? just kidding :v

output :

undefined

It says undefined. Okey, let's take another look -

code-02

num = 10;
console.log(num);
var num;

Guess again undefined ? Shouldn't it be undefined as the variable num is declared after the console.log() ? or the code should break as 10 is inserted(? will talk about later) into num before initializing it ?

output :

Great! if it matches with your thinking, if doesn't then let's discover the mystery of bermuda triangle :D

If javascript(hight level language) is your first one & only language then may be you will find it normal* but people like us coming from a low level language like C will find this fucking weird :3

It's all about hoisting. Javascript actually split the initialization and declaration and moves declarations(like var num) to the top. So actually what / how the code was we can say like this :

var num = undefined;
num = 10;
console.log(num);

So for var a variable is declared with undefined at the top, then when the line of declaration comes it assign value to it.

Then why in the first example it printed undefined ?
If we look at the code carefully we can see that, at the first code snippet, we print the value of num before store the value when it was undefined.But in the second case it was already initialized.
Actually in the first example the code were executed like this :

var num = undefined;
console.log(num); // so it was undefined when we were logging num
num = 10;

Note : This is not the actual scenario but something like this was happened. And one thing more about the words insert and initialize value to a variable , we will talk about it later.

For that reason we can call a function in js before initializing it like this -

code-03

printSum(100);

function printSum(n) {
  // print sum of 1 to n
  console.log((n * (n - 1)) / 2);
}

Let's find some corner cases how can we declare (?) or initialize variables in js.

code-04

num = 10;
console.log(num);

Now i have just removed var from the previous code (code-02). will it run properly ? Is it undefined for hoisting ? or Reference error ?

output :

As there is no var num in our code there is no hoisting. It just initialized x. This could be a different scenario if we were using strict mode. Strict mode is a feature of ES5. It applies some restrictions.

"use strict";
num = 10;
console.log(num);

In this case we will get ReferenceError: num is not defined

You can also set strict mode for individual functions too.

var note = "The whole script is not in strict mode now";

function strictMode() {
  "use strict";
  // do your stuffs
}

We have learnt about hoisting. Javascript has now a few more declaration keys like the weird var , they are let, const. Why the hack we need let or const as we already have var ? We have enough weirdness in js, why adding some more?

Wait, think positive. May be it can save us from the devil var :3

Before going to let & const, let's observe some weirdness of var and why var is the devil :3

code-05

var x = 10;
var x = "hello";
var x = true;
console.log(x);

What the hack is this ? I have initialized x with 10 which is a number , then again with "hello" string and at last with a boolean true. Is the program runnable ? error error error ? reference error ?

Let's see the output :

true

For hoisting, x was declared at the top before execution and then it was initialized with 10,"hello" and true accordingly.As at the last before logging it was a boolean, it printed true.

var actually declares a function-scoped or globally-scoped variable. There are some interesting facts here. Usingvar for declaration javascript moves the declaration at the top of the function(*) actually. Let's see the code -

code-06

function foo() {
  var x = 10;

  if (x > 50) {
    var x = 51;
  } else {
    var x = -1;
  }

  console.log(x);
}

foo();

output :

-1

Inside the function its always the same x.

code-07

function goo() {
  var x = 10;
  function foo() {
    var x = 20;
  }
  foo();
  console.log(x);
}
goo();

Can you guess the output this time ? 20 haa ??

Output :

Shouldn't surprise as I have told before that var declares a function scoped variable so x inside foo is hoisted at the top of the foo function not globally. That's why global x and x inside foo is not same.Let's see another example -

code-08

var x = 10;
function foo() {
  var y = 10;
}
foo();
console.log(y);

Output :

ReferenceError: y is not defined

YES! Successfully created a reference error again :3

You can't access a variable out of its scope, and thats actually gooood!

here is a nested functional scope example of var -

code-09

function google() {
  function foo() {
    var y = 10;
    function bar() {
      var p = 12;
      console.log("value of y : ", y); // will print 10
    }
    bar();
    console.log("value of p : ", p); // reference error for p
  }
  foo();
}
google();

Actually when we declare a variable it is available everywhere in the scope as well as any lower/child/inner scopes.

Beside that, as we can see declaring variables with var is risky. There is a very good possibility of using the same name of two different variables for different task and it can produce a bug which will be difficult to find out and fix it.

To solve this problem, they introduced let. const is the constant form of let actually.

In mathematics we used to say, let x ...... Most languages like Scheme adopt let from mathematical statement. If you have done some study on how js was created or how, it will be more clear to understand. btw Scheme has also let*.

Let's rewrite some of the previously written code snippets with let.

code-10

console.log(num);
let num = 10;

Output :

ReferenceError: Cannot access 'num' before initialization

code-11

let x = 10;
// .......
// .......
// .......
// .......
let x = "shifat"; // SyntaxError: Identifier 'x' has already been declared

code-12

let num = 10;
if (1) {
  let num = 1000; // num is a new variable here ,not the global one
}

console.log(num);

output :

let declares block-scoped which is limited to the scop of the block.The variable is said to be in a "temporal dead zone" (TDZ) from the start of the block until the initialization has completed. The variables are not accessible until fully initialization. let saves us a lot. Most of the weird stuffs of var is covered with let . So its safer to use let then var.

Very Beginner Level Version Controlling With Git

5hfT — Sun, 03 Oct 2021 03:12:59 +0000

Basic commands

init repository : git init
add a file : git add filename
add all files : git add .
commit : git commit -m "commit message"
check status which files you have added/deleted/modified : git status
push code : git push origin branch_name

Full Examples

Create a new repository

Create a repository : Create an empty repository in github

Then open git bash/terminal in your local pc

init project : git init (initializing our repository)

For example, let's add something into our repo. Let's add a file named README.md. You can create a file using your GUI(Graphical User Interface). In FileManager, right click on mouse and file or folder creation options will be popped up. Or you can use your shell/bash terminal to create the file.

As i'm a linux user and taking flex in front of you, I will create the file using my oh-my-zsh(a bash terminal).

create a file in bash : touch README.md (this will create a empty file named README.md in the directory you are in now, you can check current directory using pwd in terminal). You can add some content in it.

Now we have created a file and we want to add it into our repository. It does exist in our local pc not in github server yet[check if you don't believe me :)].
To upload it we need to follow some stuffs -> ['add','commit','push'].Let's do it.

Add the file in git : git add README.md.

If you are curious enough and lazy :D then you must be thinking of 'adding 100 files/folder will fuck our hand and mind!'. Actually we can add all files or files with same extension or file starting or ending with same substring and so on!

Add all files in the current dir : git add . (a dot can save your life :3)
Commit changes : git commit -m "short but meaningful commit message" -m "description can be added but its optional"

According to my previous statement, we need to push the commit but there is a small thing we need to do as we want to connect our local repo with e github server repository we have created at first. So we need to make a link/connection for the first time. Before that we will change/move/rename the branch name. If your are in a terminal you may be notice that the default branch is master now.

In the screenshot you can see some colorful text.Forgot about the first text (base) its a different stuff to describe (not related to git). After (base) next things are username@pc_name>working_directory>git_branch_name accordingly.
We here my branch name is master

We will change the default branch name to main according to github's preference.

rename branch : git branch -M main

Let me describe what we have done here. We just have changed the branch name from master to main. We could have used git branch -m main but there is a little differences between -m and -M. Actually -m define the changing but there can be a scenario where the branch name main already exist where we had to force git to change branch name. -f or --force is used to do something forcefully. -M is actually a short form of -m -f here. We will learn a lot about branch command later.

Now we need to link our local repo with github server somehow !

git remote add origin https://github.com/your_username/github_repository_name

by this command we are creating a origin / we are adding a location of our remote repository where we will push our file or pull files from.

push code to github : git push origin main (as our branch name is main)

Working on a repository

Scenario is we have a repository and we want to contribute in that open source project.

Link of the repository : git-101

First of all we need to clone the repository : git clone https://github.com/jspw/git-101.git (this will create a folder named git-101 and copy the repository)

If we wish to copy the repo into a folder as our wish, then we can just add the folder name at the end of the command like this git clone repo_url dir_name

Now we have cloned the repo and we can add changes as our wish (not exactly your wish though :3).

Lets assume we have added a file named contributor.md and other files as well. Now we need to add the files or directories.

add all files : git add .
commit changes : git commit -m 'add contributor file'
push code : git push origin main (this is a very beginner level tutorial, actually we never push code into main directly, we will lean this things later)

Note : I will write intermediate level git commands and uses later.
Follow git-101 to get update.

My First Python Package, an Auto Generator for Solved Problems in Codeforces

5hfT — Thu, 14 Jan 2021 14:29:15 +0000

I have made an python package named cp-tool and published in https://pypi.org

cp-tool is an auto generator for solved problems at different online judges. It gathers all the problems you have solved at an online judge and generates a git repository for you.

Generated Sample Git Rep by cp-tool

Supported Platforms

Codeforces

Requirments

python >=3.6

Instruction

Installation
- Linux :

pip install cp-tool

Windows :

python -m pip install cp-tool

Note : Please updated version

Upgrade :
- Linux :

pip install --upgrade cp-tool

Windows :

python -m pip install --upgrade cp-tool

Usage
- Using command cp-tool it will show the usages
- Init with git repo :
- Create a git repository first
- Then init
```
cp-tool -c init -j codeforces
```
You will be asked for
- handle
  - example : shifat57
- repository name (A folder will be created based in repo name)
  - example : My Cp Track
- repository url
  - example : https://github.com/jspw/cp-tool-sample
- Update submissions :
- Go to the repository folder in your local file
- Then
cp-tool -c update -j codeforces

License

MIT

Check Source Code
Sample Repo generated by cp-tool

Make Your Own Custom Android Launcher using Flutter

5hfT — Wed, 23 Sep 2020 09:30:48 +0000

Have you ever thought of making your own stuffs and use them?

Like your Own

Operation System !
Programming Language !
Library !
Framework !
Apps !
Games !

I'm that kind of person who was always interested in making applications which are integrated to the system (literally Applications) not business or commercial applications and still i am :3

I have always dreamt about things of my own...

So once I thought to make my own Android Launcher as I'm using Android Phones.

At first I thought it's something very hard and I won't be able to make a launcher.Then I found it supper easy!

Today i am going to discuss about how to nake your Android Launcher !

Let's start!

I am using Flutter which is a Cross Platform Framework of Dart Made by Google.

There is a big community of Flutter to make cross platform applications such as Android,IOS,Desktop and Web applications.

If you haven't installed flutter yet then have a look at their doc which is very user friendly and well decorated.

Install Flutter

Note : I am using Visual Studio Code as a Editor or IDE and prefer terminal and command line activities.

Lets create a flutter application

Command in terminal :

flutter create -i objc -a java custom_launcher

Note : This command will create a application named custom_launcher and the native code for Android will be java

If you prefer Kotlin then just use -

flutter create custom_launcher

A flutter app will be created with similler file Structure:

We will code in main.dart file.

First We will need to edit some codes in the AndroidManifest.xml file. That will make our launcher different from normal Android Applications

Manifest file location :

Add these lines in AndroidManifest.xml file under <intent-filter> section :



<category android:name="android.intent.category.HOME" />
<category android:name="android.intent.category.DEFAULT" />

Now If you run your app , it will appear as a Launcher.

Or Press Home button of your android phone and it will ask to set it as default launcher.

Congrats You have made your launcher :D

Yup Seriously ! It is that easy !

Now as a Flutter Application developer I hope you are able to do some of your own customizations.

I know you are concert about how can you show the installed applications in your custom Launcher.

Let's do it:

Interact with the Applications installed in Phone

To do so we will use a flutter plugin named device_apps which will give us a List<application> where all the necessary informations will be given.

First import device_apps into your dart file :



import 'package:device_apps/device_apps.dart';

Get the list of apps available in your phone :




List<Application> apps = await DeviceApps.getInstalledApplications();

You can send some parameters too :




List<Application> apps = await DeviceApps.getInstalledApplications
(
    includeAppIcons: true,
    includeSystemApps: true,
    onlyAppsWithLaunchIntent: true,
)

This will return something like that :

It provides :

App Name (String)
Apk File Path (String)
Package Name (String)
Version Name (String)
Version Code (int)
System App ? (bool)
Install Time (int)
Update Time (int)
Application Catagory (Catagory Type)

It also provides icon as ApplicationIcon.
To access icon you have to use that Application type as ApplicationWithIcon and check that the app has a icon first.

Note : icon is a Uint8 List type.

Now You have your data so do what ever you want !

Let me show you how you can use them

Let's traverse all the apps we get before :




for (int i=0;i<apps.length;i++){
    Application app = apps[i];
}

Extract the application name :




Text(app.appName)

Use Icon :




app is ApplicationWithIcon ? CircleAvatar(
 backgroundImage:
     MemoryImage(
   app.icon,
 ),
)

Note : If you are not able to access app.icon then use this -




ApplicationWithIcon icon app as ApplicationWithIcon;
icon = icon.icon;

More things you will want to do :

Check if an application is installed :




bool isInstalled = await DeviceApps.isAppInstalled('packageName');

Open an Application :



DeviceApps.openApp('packageName');

Apps can be shown like this :

I have made an Android Launcher which is lightweight and Fast.You can have a look and If you like then give me a star :v

Source Code available : Ubuntu Launcher

Apk Release : Install

Happy Coding :D

Contact with | Follow me on : LinkedIn Twitter Facebook GitHub Quora Dev Medium

Host Your Django Project in pythonanywhere Free

5hfT — Wed, 12 Aug 2020 20:07:09 +0000

PythonAnywhere is an online integrated development environment and web hosting service based on the Python programming language.
You can host your pet projects here which is free.

Let's start :

Go to PythonAnywhere
Create account and login
Go to consoles
Select bash console
Create virtual environment for python

mkvirtualenv --python=python3.8 envname

Your environment will be activated and in bash you will see the envname in parenthesis
Install django

pip install -U django==3.0.3

check django path

which django-admin.py

install necessary packages

pip instal xyz

Clone git repo

git clone repo.git

Note : You should have a git repo of the project or web application

Go to dashboard of pythonanywhere.com and go to Web
Select create new web app
- next
- select manual configuration
- next next done !
Here you will see the url for your project click and you will see hello world page which is default for python
Config WebApp :
setvirtualenv path which you will find in console using

which django-admin.py

set source code as /home/username/projectname
static files
- set /static/admin/ as /home/username/.virtualenvs/blog/lib/python3.8/site-packages/django/contrib/admin/static/admin
- set /static/ as your project static folder path as mine is /home/jspw/shifat.com/blog/static
set Virtualenv dir as /home/username/.virtualenvs/env_name
Edit WSGI configuration file as the file given below

import os
import sys
## assuming your django settings file is at '/home/jspw/mysite/mysite/settings.py'
## and your manage.py is is at '/home/jspw/mysite/manage.py'
path = '/home/jspw/mysite'  #path of your project
if path not in sys.path:
    sys.path.append(path)
os.chdir(path)
os.environ.setdefault('DJANGO_SETTINGS_MODULE', "food_menu_project.settings")  #projectname.settings
import django

django.setup()
from django.core.wsgi import get_wsgi_application
application = get_wsgi_application()

Done ! Clik on the reload in the webapp page then go to the website url and boom!!!

Note : Check settings.py file and you have allowed your host url.

Pointer in C/C++

5hfT — Fri, 17 Jul 2020 07:01:05 +0000

Pointer in C/C++

Let's consider a int type variable var.

int var = 10;

So if we print var it will be like :

printf("%d",var);

Output : 10
There is a location in our system memory where every variables are stored when we declare them.
So where is the variable var ?
To print the momory address or location of a variable we have to use unary & operator

print("The memory address of a is %p: ",&a); //%p is used to print a pointer

Output :The memory address of a is : 0x7fffbabdb6f0
The memory address can be different as it takes a random memory address everytime you build your program, but looks like same(0x..........).
Let's declare a pointer :

int *pa; // or int * pa

Note : If you are pointing the pointer at a data type you have to declare it at the declaration of the pointer
Now point Pointer pa at var;

pa = &var;

Now the pointer is pointed at the var variable and it takes the location or memory address of var.
Let's print pa :

printf("%p",pa);

Output : 0x7fffbabdb6f0
Which is same as the memory address of var variable.
We can also print the value of a memory address using unary * operator.This is also called dereferencing

printf("%d",*pa);

Output : 10
Now we can say a Pointer is an object in many programming languages that stores a memory address.
Let's see what happens if we change the value of var.

var = 10001;
printf("Value of var : %d\n",var);
printf("Value of memory  address %p is : %d",pa,*pa);

Output :

Value of var : 10001
Value of Memory address 0x7fffbabdb6f0 is : 10001

We can see changing the value of var changes the value of pa memory address.
What if we increase the value of the Pointer pa ? Let's see:

pa++;
printf("Pointer (pa) is pointed to %p and value becomes : %d\n", pa, *pa);

Output :

Pointer (pa) is pointed to 0x7fffbabdb6f8 and value becomes : -1161971980

Here -1161971980 is a gurbage value as nothing is initialized in memory address 0x7fffbabdb6f8

Pointer Expressions and Pointer Arithmetic:

A limited set of arithmetic operations can be performed on pointers. A pointer may be:

incremented ( ++ )
decremented ( -- )
an integer may be added to a pointer ( + or += )
an integer may be subtracted from a pointer ( – or -= )

Pointer arithmetic is meaningless unless performed on an array.
Note : Pointers contain addresses. Adding two addresses makes no sense, because there is no idea what it would point to. Subtracting two addresses lets you compute the offset between these two addresses.

Pointer in Arrays

Declare an array:

int ar[] = {1, 2, 3, 4, 5};

Declare pointer variable:

int *ptr;

Assign the address of v[0] to ptr

ptr = ar; //We can use ptr=&ar[0];(both are same)

Let's print array elements with thieir memory address :

for (int i = 0; i < 5; i++)
{
    printf("Value of *ptr = %d\n", *ptr);
    printf("Value of ptr = %p\n", ptr);

    // Increment pointer ptr by 1
    ptr++;
}

Output :

Value of *ptr = 1
Value of ptr = 0x7fffe4378a30
Value of *ptr = 2
Value of ptr = 0x7fffe4378a34
Value of *ptr = 3
Value of ptr = 0x7fffe4378a38
Value of *ptr = 4
Value of ptr = 0x7fffe4378a3c
Value of *ptr = 5
Value of ptr = 0x7fffe4378a40

We can also use :

for (int i = 0; i < 5; i++)
{
    cout<<ptr[i]<<" ";
}
cout<<endl;

Output : 1 2 3 4 5
As an array name acts like a pointer constant. The value of this pointer constant is the address of the first element.

Pointer to pointer
Have you even think that if a variable has a memory address in the memory then what about the pointer we are using to point on the variable?
Yes,a pointer also has a memory address.

int sum =10;
int * psum = &a;
printf("Memory address of variable(sum) : %p\n",psum);
printf("Memory Address of pointer(psum) :  %p\n",&psum);

Output :

Memory address of variable(sum) : 0x7ffc3b46638c
Memory Address of pointer(psum) :  0x7ffc3b466398

Let's declare a pointer for a int pointer :3

int **ppsum = &psum; //as ppsum is a pointer of a int type variable's pointer

print the memory address of the pointer :

printf("Memory Address of pointer(psum) :  %p\n",ppsum);

Output :

Memory Address of pointer(psum) :  0x7ffc712e6780

Pointer in Structure

Structures are user defined data types.

Let' see a structure

struct Person
{            //structure
    int age; //members
    float salary;
};

In the Person structure there are two member int type and float type.Person is also a data type here.

So the Person data type also invoke memory and has a memory address.

struct Person p1;

printf("%p",&p1);

Output:

0x7ffebf9ffab0

Let's declare a pointer and point to the structure.

struct Person *p;
p=&p1;
printf("%p",p);

Output:

0x7ffebf9ffab0

We can also use pointer to change values:

p->age = 25; //or *(p).age = 25
p->salary = 2121324.50

Pass by Value

void passByValue(int x){
    x = 20;
    print("In passByValue function, x = %d\n",x);
}

int main(){
    int x = 10;
    passByValue(x);
    print("In main Function, x = : %d\n",x);
    return 0;
}

Output :

In passByValue function, x = 20
In main Function, x = : 10

In this case, x in passByValue() function and x in main() function are not same, just the variable names are same but they indicate two different memory locations.
Let's go deeper :3

void passByValue(int x){
    cout<<"In passByValue Function : "<<endl;
    x = 20;
    printf("x = %d\n",x);
    cout<<"Memory address of x = "<<&x<<endl;
}

int main(){
    int x = 10;
    passByValue(x);
    cout<<"In main Function : "<<endl;
    printf("x = %d\n",x);
    cout<<"Memory address of x = "<<&x<<endl;
    return 0;
}

Output :

In passByValue Function :
x = 20
Memory address of x = 0x7ffc6c07397c
In main Function :
x = 10
Memory address of x = 0x7ffc6c0739a0

So looking at the outputs we can find that the memory addresses are not same ! The two x are not same.

Pass by Reference

void passByReference(int *px){
    *px = 100;
    printf("In passByReference() function, Memory address =  %p\n",px);
}

int main(){
    int x = 10;
    cout<<"(Before) Value of x : "<<x<<endl;
    passByReference(&x);
    cout<<"(After) Value of x : "<<x<<endl;
    cout<<"Memory address of x = "<<&x<<endl;
    return 0;
}

Output :

(Before) Value of x : 10
Memory address =  0x7ffe2bd44670
(After) Value of x : 100
Memory address of x = 0x7ffe2bd44670

In pass by reference we are sending the memory address of x and then in the function we are chnaging the value which is stored in the memory address.
So chaging value of memory address will also chnage the value of a as it is stored in the memory address.

Dangling Pointers

int* getValue(){
    int x;
    x=2;
    return &x;
}

int main(){
    int *px = getValue();
    print("Value in memory address(px) = %d\n",*px);
}

Output : Value in memory address(px) = 2

In this case getValue() returns the memory address where x were stored. After returning memory address x vanishes but the value in that address remains and after that if we take a variable like

int var3 = 120

there is a huge possibility that var3 can be stored in that memory address which can make problem for you and that is called Dangling Pointer

Dangling pointers arise during object destruction, when an object that has an incoming reference is deleted or deallocated, without modifying the value of the pointer, so that the pointer still points to the memory location of the deallocated memory.

So hare comes the term Dynamic Memory Allocation

Dynamic Memory Allocation

Sections in Memory management:

Stack
Heap
BSS
Data
Code

C Dynamic Memory Allocation can be defined as a procedure in which the size of a data structure (like Array) is changed during the runtime.

There are 4 library functions provided by C defined under header file to facilitate dynamic memory allocation in C programming. They are:

malloc()
calloc()
free()
realloc()

C malloc() method

“malloc” or “memory allocation” method in C is used to dynamically allocate a single large block of memory with the specified size. It returns a pointer of type void which can be cast into a pointer of any form. It initializes each block with default garbage value.

Syntax:
ptr = (cast-type*) malloc(byte-size)

For Example:

int* ptr = (int*) malloc(100 * sizeof(int));

Since the size of int is 4 bytes, this statement will allocate 400 bytes of memory. And, the pointer ptr holds the address of the first byte in the allocated memory.

C free() method

“free” method in C is used to dynamically de-allocate the memory. The memory allocated using functions malloc() and calloc() is not de-allocated on their own. Hence the free() method is used, whenever the dynamic memory allocation takes place. It helps to reduce wastage of memory by freeing it.

free(ptr);

Note:When we declare a pointer it pointed to a random memory address of the memory so better practice is to set them null first

int* px = NULL;

C calloc() method

“calloc” or “contiguous allocation” method in C is used to dynamically allocate the specified number of blocks of memory of the specified type. It initializes each block with a default value ‘0’.

Syntax:

ptr = (cast-type*)calloc(n, element-size);

For Example:

ptr = (float*) calloc(25, sizeof(float));

This statement allocates contiguous space in memory for 25 elements each with the size of the float.

Note:alloc() function allocate n bytes in memory where calloc() function allocate x blocks of y bytes in memory

C realloc() method

“realloc” or “re-allocation” method in C is used to dynamically change the memory allocation of a previously allocated memory.

Syntax:

ptr = realloc(ptr, newSize);

where ptr is reallocated with new size 'newSize'.

int* p = (int*)malloc(n*sizeof(int));
p = realloc(p,n*sizeof(int));

for more Dynamic Memory Allocation and Fragmentation in C and C++

How To create Alarm and Notification in Android using Flutter?

5hfT — Fri, 10 Jul 2020 09:31:14 +0000

I am making an Android application and need to make set alarm option and set that the app will give notifications at a fixed time or something.I'm using Flutter. How can i do that?

A OS Cleaner for Debian Based Linux distributions !

5hfT — Wed, 17 Jun 2020 17:03:58 +0000

I have written a python script that will show and delete the unnecessary caches and files from a operating system (debian based ).

This sript will clear the :

packages that are no longer required
Clean up APT cache
systemd journal logs (more than 7 days)
Clean the thumbnail cache

Most of the time these files takes a lot of storage !
and using a bunch of commands to remove them are quit boring .
So i have gathered the commands and added them in a python script.
Here is my git repo have a look

Usages :

Clone repo :git clone https://github.com/jspw/Cleaner.git
Chnage directory : cd Cleaner
Check the caches : sudo python cleaner.py -s
Clear the caches : sudo python cleaner.py -c

feel free to suggest any option or command to add or report any error in the script .
Thanks

Live Input Output (Competitive Programming) setup in VS CODE for C/C++ (WINDOWS)

5hfT — Fri, 22 May 2020 17:44:14 +0000

How to install and setup vs code for competitive programming with c/c++ for Windows Users

install vs code

Download vs code : Link
Install in your pc

Setup environment for c/c++

install mingw : link
In you pc search for system environment

go to Environment variables

Go to system varibale and click on path

click edit
select new
paste the link where you mingw bin folder . for me it is C:\MinGW\bin
- find it there
select ok ok for everything

Install git

download link Link

Then

Open Vs code
Open your coding folder file->open folder
press ctrl+~ and the terminal will be opened at the bottom

if in the terminal u find that its cmd or powershell then click on cmd/powershell and select 'set default sell' and select git
- Now click on the delete icon and press ctrl+~ and its saying your shell is bash!
if still bash no showing then close vs code and open vs code again

Run a programme for testing :

create a file hello.cpp
write code to print hello
in terminal use the command
```
g++ hello.cpp -o test && ./test
```
If you find hello then congrats
if saying g++ not found then try to close vs code and then oepn vs code again.

Setup Vs Code

Clik on terminal (At the top)
select configure task
select create task.json from template
select other and new task.json file will be created
now copy and paste the my task(windows).json {link is here} file into your task.json file
done

More things to do :
Note : You just need to do these things only for the first time of your workspace!

Split screen in 3 sections
- split the main section in right (right mouse click on the .cpp file and u will get the split options)
- then split the right into down (same as above)
create a file named input.txt
create a file named output.txt
open input.txt into the upper right section
open output.txt into the lower right section

This will be the final look of your vs code

Now create a folder and create your file .cpp inside the folder and give inputs in input.txt and press `Ctrl+Shift+b` and your output will be in the output.txt file

Note : Don't keep the cpp file in the base folder. I mean you have to create one or more folders in the base folder (Base folder means where you opened your vs code or you can say vs code wrokspace folder).and the input and output file should be in the base folder.

Folders should be like this or similer :

Not This

Press `Ctrl+Shift+b` and your output will be in the output.txt file

Happy coding :3

Make Competitive Programming Easy with VS Code

5hfT — Sun, 12 Apr 2020 14:59:19 +0000

Make Coding Easy

This tutorial is for linux (debian based) only

If you are a windows user then check this out Setup VS Code for windows

1. VS code task config to make competitive programming easy and programme ananlysis !

This is a .json file which will help you to run your cpp file with one click or shortcut.
In this case , you don't need to write input in the command line or write fopen / close stuffs , programme will take input from a file (input.txt) automatically and give the output in another file (output.txt) .

You can also find the programme runtime status which will help you to calculate execution time as well as memory usage and many more !

pre-requirments :

Visual Studio Code
gcc/g++
time
- install time : sudo apt install time

More things to do :
Note : You just need to do these things only for the first time of your workspace!

Split screen in 3 sections
- split the main section in right (right mouse click on the .cpp file and u will get the split options)
- then split the right into down (same as above)
create a file named input.txt
create a file named output.txt
open input.txt into the upper right section
open output.txt into the lower right section

This will be the final look of your vs code

How to setup :

Go to Configure Default Build Task...
- In Menu bar
  - Clik on terminal (At the top)
- select configure task
- select create task.json from template (this will create a task.json file in .vscode in your working directory)
- select other and new task.json file will be created
- now copy and paste the my task(cpp).json {link is here} file into your task.json file
- done

Usage :

Run :
- Shortcut type : ctrl+shift+b
You nee to give the input in the input.txt file
output will be shown in the output.txt file
##### Bonus : programme status will be shown in the sys.txt file
people concern about more details such as binary form and disassemble code can check tasks(more).json file

2. VS CODE Snippet :

This one is made for my personal usage ,you can add functions as you wish and edit my name and doc

Download the cpp.json file
Select User Snippets under File > Preferences (Code > Preferences on macOS), and then select cpp.json
copy or replace the cpp.json file with downloaded file and save !

Happy Coding with VS Code

You can check my git repo VS-Code-Config

I have added some more files for python too !

Forem: 5hfT

I built a VS Code extension to see what Claude Code is actually doing across all my projects

Cool, Fancy & Cutting Edge Shits I have Learnt Recently

The Weird Javascript

Table of Contents

Contents

Undefined || Error ?

code-01

code-02

code-03

code-04

code-05

code-06

code-07

code-08

code-09

code-10

code-11

code-12

Very Beginner Level Version Controlling With Git

Basic commands

Full Examples

Create a new repository

Working on a repository

My First Python Package, an Auto Generator for Solved Problems in Codeforces

Supported Platforms

Requirments

Instruction

Installation

Upgrade :

Usage

License

Make Your Own Custom Android Launcher using Flutter

Have you ever thought of making your own stuffs and use them?

Today i am going to discuss about how to nake your Android Launcher !

Lets create a flutter application

A flutter app will be created with similler file Structure:

Congrats You have made your launcher :D

Interact with the Applications installed in Phone

It provides :

Let me show you how you can use them

More things you will want to do :

Apps can be shown like this :

Host Your Django Project in pythonanywhere Free

Let's start :

Config WebApp :

Pointer in C/C++

Pointer in C/C++

Pointer Expressions and Pointer Arithmetic:

Pointer in Arrays

Pointer in Structure

Pass by Value

Pass by Reference

Dangling Pointers

Dynamic Memory Allocation

C malloc() method

C free() method

C calloc() method

C realloc() method

How To create Alarm and Notification in Android using Flutter?

A OS Cleaner for Debian Based Linux distributions !

This sript will clear the :

Live Input Output (Competitive Programming) setup in VS CODE for C/C++ (WINDOWS)

How to install and setup vs code for competitive programming with c/c++ for Windows Users

install vs code

Setup environment for c/c++

Install git

Run a programme for testing :

Setup Vs Code

This will be the final look of your vs code

Now create a folder and create your file .cpp inside the folder and give inputs in input.txt and press Ctrl+Shift+b and your output will be in the output.txt file

Folders should be like this or similer :

Not This

Press Ctrl+Shift+b and your output will be in the output.txt file

Happy coding :3

Make Competitive Programming Easy with VS Code

Make Coding Easy

1. VS code task config to make competitive programming easy and programme ananlysis !

This will be the final look of your vs code

2. VS CODE Snippet :

Now create a folder and create your file .cpp inside the folder and give inputs in input.txt and press `Ctrl+Shift+b` and your output will be in the output.txt file

Press `Ctrl+Shift+b` and your output will be in the output.txt file