This project creates a Slack version for the Command Line where users can register themselves, join #channels and send Direct Messages(DM).
The project is built by:
- Creating a basic TCP Custom Protocol for structuring the commands given by the clients.
- Parsing and handling each command in a concurrent server working with goroutines.
- Client and Server structs based on go channels for managing the flow of data.
- Logging all activity in the Server and being verbose with the Client when using commands.
- First of all you need to have Go installed in your machine. For info about this point go to the Download page of the official site.
- Clone this repo in your computer:
git clone - Server: Open a session in your terminal, go to the project folder and run the server:
go run .. This will create a server running in local (127.0.0.1) and listening the port 3000. - Clients: To use clients you need to clone the Minislack-Client repository and run the client following the instructions in the README.
- Once your server is up and running, you will get to see the log whenever a user executes a command.
For this project to work, I have created a custom protocol to control all the activity between the server and the clients. The protocol is designed on top of TCP and is text-based.
- REG
- JOIN
- LEAVE
- MSG
- FILES
- SEND
- GET
- CHNS
- USRS
The structure of this command is: REG @username.
- This command is used to let a user register himself in the server.
- Not an action will be allowed by the server if the user isn't registered.
- The server returns a successful response if that username value is available.
The structure of this command is: JOIN #channel.
- This command is used to let a user join a channel for writing and receving messages through it.
- If the channel the user is trying to join doesn't exist, the server will create it and automatically will join him/her.
The structure of this command is: LEAVE #channel
- This command is used to let a user leave a channel, stopping more incoming messages to flow or the user to send new ones.
- If the channel doesn't exist, the server will send the client a message with a failure description.
The structure of this command is: MSG #channel <length>\r\n<body> or MSG @username <length>\r\n<body>
- This command is used to send messages to channel or direct messages to users.
- The
<length>part of the command must be equal to the length of the message body. - The carriage return
\r\nis a delimiter used before the body. - The
<body>is the message itself. - When a message is sent to a channel, the channel then broadcasts it to all its joined users.
The structure of this command is: FILES #channel
- This command is used to ask the server about files stored in a specific channel.
- The server answers with the list of files stored within the channel.
The structure of this command is: SEND #channel <filename> <path>
- This command is used to send and save a file in a specific channel.
- The
<filename>part of the command is the name you want to use to save a file. Is like using the "Save as.." button in the web. - If the name you are trying to use isn't available, you will get an error message asking to try a different one.
- The
<path>part of the command is the relative or absolute path to the file you want to save in the channel. Try using./tmp/data.txtor./tmp/check.pngfor testing.
The structure of this command is: GET #channel <filename>
- This command is used to ask for a file that is stored in a specific channel.
- The file is stored by default in the
./downloads/folder of the client. - If the client already has a file with that name in the
./downloads/folder, the Client will handle it by appending an incremental number to differentiate them.
The structure of this command is: CHNS
This command is used to receive (the client) all the existing channels in the server.
The structure of this command is: USRS
This command is used to receive (the client) all the users currently registered in the server
Thanks to Ilija Eftimov for his article Understanding Bytes in Go by building a TCP protocol. It was pretty helpful for creating this minislack project, mainly an extension of his work.