Write a program in C that perform login operation. The program will accept username and password as a string from the user. The valid username should be “user” and the valid password should be “default”.
If either of the username or password is incorrect then it should display the appropriate message. If username and password entered is correct, then it should display the message “User successfully logged in…”.

Here is the C program:

#include<stdio.h>
#include<conio.h>
#include<string.h>
void main()
{
	char *username;
	char *password;
	clrscr();

	printf("Enter the username: ");
	gets(username);

	printf("\nEnter the password: ");
	gets(password);

	if(strcmp(username, "user") == 0){
		//username verification sucessful
		//next step is to verify the password
		if(strcmp(password, "default") == 0){
			//password verification also successful
			printf("\nUser successfully logged in...");
		}else{
			//invalid password. Report it
			printf("\nPassword entered is invalid");
		}
	}else{
		//invalid username. Report it
		printf("\nUsername entered is invalid");
	}

	getch();
}

Output:

Enter the username: user

Enter the password: default

User successfully logged in...

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