Interprocess Communication With C Programming and IoL Graphical Shell

Video Demonstration

YouTube Video Demonstration

Requirement

ioL graphical shell is required to run this program. To learn more about ioL, refer to ioL's documentation

Description

Simple display server displaying information from multiple clients on one screen, based on sockets.

Server:

• Receives connections of up to 5 clients.
• Receives client names and messages to separate windows.
• Allows clients to shut down the server by click of a 'shutdown' button.

Client:

• Sends data required to be displayed on the server (plain text or a file that contains plain text).

How to Run

1. Open your terminal (by default in Ubuntu Mate: right click within the folder -> Open in Terminal) where the file server.c is located.
2. Enter the following command: gcc server.c -o server;sudo ./runstandalone.sh
3. Enter the password of your account requested by the system.
4. Server window will launch. Press [RightCtrl+F7] to temporary hide it.
5. Open new terminal. Refer to step 1.
6. Refer to step i to manually send message, or to step ii to assign a file that contains a message
   1. Enter the following command: gcc client.c -o client;./client
      • Type any message into the client Terminal and press [CTRL+D] to send the message to the server. Press RightCtrl+F8 to launch server window.
   2. Enter the following command where 'filename' is the name of the file that contains a message: gcc client.c -o client;./client < filename
      • 5 seconds is given to preview the message on server side. Client is then terminated automatically.

Server Termination

• Press [CTRL+C] in the Server Terminal
• Press Shutdown button on the server side window.

Client Termination

• Press [CTRL+C] in the Client Terminal
• Type quit in the Client Terminal and press [CTRL+D]

Keyboard Shortcuts

Key	Usage	Description
CTRL+C	Client & Server Terminal	Terminates a Client or the Server
CTRL+D	Client Terminal	Sends a message to the Server
ENTER	Client Terminal	Allows users to type on a new line
RightCtrl+F7	Server Window	Switches to Linux View
RightCtrl+F8	Linux View	Switches to Server Window

Assumptions

Assumption	Description
Client Execution	Server must be running before connecting the client
Client Reconnection	Reconnecting clients are treated as new clients
Redirection From File	The following command: gcc client.c -o client;./client < filename connects to the server and displays file's content in plain text for 5 seconds and disconnects the client. Input is not allowed.

Extra Features

Feature	Description
Server Capacity	Server rejects more than 5 clients and clients are notified.
Online Status	Server displays number of connected clients.
Client Window Reset	Server resets its content if number of concurrent users becomes 0.
Client Name	Server interprets client names as unique but clients are not aware of it. Client sees its name as the name of the executable file.
Socket File Location	File is stored in tmp folder. File is removed on restart / shut down of the server. File's directory: /tmp/a2-.socket.

Limitations

Limitation	Description
Server Termination	Clients are disconnected once server is disconnected.
Client Communication	No direct communication between clients is allowed. All the communication is displayed in the server's window.
Client Interaction	User has no interaction with the server's window. Shutdown button is available for use only.
Client Disconnection	Window of disconnected client remain open. Once the same client is reconnected, the previously used window is not utilised and a new window is created instead. Windows are cleared once client count reaches 0.

Known Bugs

Bug	Description
Client Disconnection & Reconnection	Server might get stuck in infinite loop when client's keep disconnecting or reconnecting.