What is GDB?

The GNU Debugger (GDB) is a command line tool used to debug C/C++ applications.

Installing GDB

Easiest way is to use the min-gw package on Windows.

Using GDB

Compile your program using ` gcc -Wall -g myprog.c `

  • -Wall flag gives all warnings
  • -g flag compiles in debug mode. Thus is preserves the identifiers and symbols

Start your program using gdb usign gdb a.out

If your program uses command line arguments you can do it using gdb a.out argument1 argument2 ...



int main(){
	int n = 5;
	for(int i = 0; i < n; i++){
		printf("%d\n", i);




Typing list prints 10 lines of code each time you invoke it. Invoking list again will print the next 10 lines.

list n can be used to print 10 lines starting from the nth line where n is a number. Eg list 6 will print lines starting from 6 to 16.

list FUNCNAME can be used to print a function. Eg list main.

list START:END can be used to print lines starting from START and ending at END