DEV Community: Sushant Gupta

Getting Started With GDB!

Sushant Gupta — Mon, 08 Jun 2020 05:59:39 +0000

This is the Part 2 of Debugging Series

If you don't know what is GDB, i highly recommend to check the part 1 of this series!

Nowadays, i am learning & practicing coding questions of Data Structures & Algorithms over various coding platforms such as CodeChef, Hackerearth etc.

Most of the time when i stuck in some question or if i am not able to get the problem statement properly!
What i usually do is firstly i give time to the problem & if found that i missing somewhere due to which i'm not able to solve the problem!
In that case i refer to the problem's editorial section in which author has curated the explanation well & the prefix solution hint!

What i faced sometimes, that after seeing the solution if i am not to able to understand the code, what that code does & how code is executing?

In this case i debug the code, which plays a vital role!

So, Let's Get Started!

In my first part, I've explained what is debugging? & how to install GDB debugger! Go check it out if you haven't!

I follow some certain commands while debugging in almost every code!

Let's take a simple code for finding sum of first n natural numbers!

#include<iostream>
using namespace std;
int main(){
    int n;
    cin>>n;
    int i, sum = 0;
    for(i = 1; i <= n; i++){
        sum += i;
    }
    cout<<sum<<"\n";
    return 0;
}

GDB offers a big list of commands, however the following commands are the ones used most frequently:

b main - Puts the breakpoint at the beginning of the program i.e., from main() , we can set breakpoint anywhere in the program!

r - Runs the program until a breakpoint or error
After setting breakpoint, i usually start the program for execution by writing r , it starts from the next line after the main()

s - Runs the next line of program or if u want to go inside any function then just hit s !

n - Like s, u can use this command also, but it does not step into functions!

I use n most of the time instead of s ,here i've taken n = 20

p var - Prints the current value of the variable "var", here variable are sum, so write p sum to check the final sum = 210 !

q - Quits GDB, after finishing the execution, quit the GDB Debugger by hitting y !

Now, U Can Debug Any Program!
So, Lets Start Debugging Codes!

Here, are some more commands, in case u stuck somewhere!

b - Puts a breakpoint at the current line
b N - Puts a breakpoint at line N
b +N - Puts a breakpoint N lines down from the current line
b fn - Puts a breakpoint at the beginning of function "fn"
d N - Deletes breakpoint number N
info break - list breakpoints
c - Continues running the program until the next breakpoint or error
f - Runs until the current function is finished
s N - Runs the next N lines of the program
u N - Runs until you get N lines in front of the current line
bt - Prints a stack trace
u - Goes up a level in the stack
d - Goes down a level in the stack

Thanks for giving this a read! XD

HAPPY CODING

Customize Your Code Editor (VSCode) For Competitive Coding & Development

Sushant Gupta — Mon, 18 May 2020 09:13:27 +0000

From my freshman year i started coding & learning various tech stack to explore the fields of Computer Science Technology.
However, most of the things went well as planned to move on different technologies!
But, whenever i shift myself for learning new & different tech stack, the same issue always strikes in my mind why to change myself to code on different Code editor and IDE which is quite annoying for me & seems the same for you!

So, Gradually things changed as most of you already know being a computer science student, that programming is must & if you do Competitive Programming then its like a cherry on cake to get you in good firm!
Therefore, now a days i'm doing Development & Competitive Coding in parallel, hence i don't want to shift myself for different coding editors for different purposes!

Therefore, i customize my primary code editor to work for different environments & hence it works pretty well!

That Code Editor is none other than Visual Studio Code by Microsoft!

It's been 18 months that i'm using it & fall in love with this amazing code editor which is maintained globally as an open-source software!

You can download this code editor for your Operation System from here

Here is some preview of mine workplace :

For Web Development :
For Competitive Coding :

Do you like it?

You can do the same to create such environment with just few steps!

Here You Go :

Download VSCode (Visual Studio Code) from above link mentioned!
Open Extension Side Panel in VSCode or hit this short-cut key ctrl+shift+x
Install Settings Sync Extension :

After Installing, Reload the extension in VSCode!
Hit the following keys to download my configuration :

Shift + Alt + D
(on macOS: Shift + Option + U / Shift + Option + D)

You will see this type of interface :

Following are the steps you need to perform to configure.
- Click on Login with GitHub .
- Login GitHub on Browser and close the browser tab once you get Success message.
- Copy & Paste My GitHub Token & Gist Id in the pop-up interface of Setting Sync Extension!
  - GitHub Token - b881e6e5c75e5e6b407d1b796529da47acd14e08
  - GitHub Gist Id - ac9386100024b91a298b39d61959a885
Last step to hit the download keys again : Shift + Alt + D
Once you select download, after downloading. Settings Sync will display you Summary containing the list of each files and extension being downloaded.
New popup will be opened to allow you to restart the code to apply the settings.

That's it, Now you are good to go!

Disclaimer : My Setting & Configuration are for Web Development & Competitive Coding in C++ (mainly) but you can do this for any programming language with some little changes!

If you have any query or facing some problem regarding this, you are always welcome to ask for any help!
Just comment down, i'll there to help you!

Thanks for giving this a read!

Happy Coding XD