Multi$-$threaded and Multi$-$user Chat Application with using C language.

In this project, you are expected to develop a messaging server and client using socket programming. In this system, there will be multiple clients and a single server. Clients will communicate with the server using the LIST, LOGIN, LOGOUT, MSG$,$ INFO, and REGISTER commands.

Requirements

The messaging server and client you develop must support at least the following commands:

$1.$ LIST

o Used to list the users on the server and their online$/$offline status.

o Usage: LIST $[$mask$]$

o mask indicates the listing mask created with $*$ or $?$

$2.$ LOGIN

o Allows a user to log into the system.

o Usage: LOGIN $[$mood$]$

$$ username: The user's name.

$$ password: The user's password.

$$ mood $($optional$)$: The user's current mood.

$3.$ LOGOUT

o Allows the active user to log out of the system.

o Updates the user's status on the server and terminates the thread associated with this user.

$4.$ MSG

o Sends a message to a specific user or all online users.

o Usage: MSG

$$ username: The name of the user to whom the message will be sent. If $*$ is used, the message is sent to all online users.

$$ message: The text of the message to be sent.

$5.$ INFO

o Shows the first name, last name, and mood of the specified user.

o Usage: INFO

$$ username: The name of the user whose information is requested.

$6.$ REGISTER

o Allows a new user to register in the system.

o Usage: REGISTER

$$ username: The name of the new user.

$$ firstname: The first name of the new user.

$$ lastname: The last name of the new user.

$$ password: The password of the new user.

Persistence

$$ The messaging server and client application to be developed should be designed to work continuously and be reusable. Users should be able to continue messaging and communicating as long as the system is not shut down.

Client Application

$$ The client application will show from whom the message was received when a message is received.

$$ Commands can be taken one by one or in bulk; you are free in this regard.

Multi$-$threading

$$ A separate thread will be created for each user who logs into the system, and the application will work in a multi$-$threaded manner.

Storing User Information

$$ User information will be stored in a text file. This file will contain usernames, first names, last names, passwords, and mood information.