Simple Go HTTP Server

This is a basic HTTP server written in Go. It listens on a specified port and handles various HTTP requests, including serving files, echoing content, and returning the User-Agent string.

Features

Echo Endpoint: Returns the content appended to /echo/ in the URL.
User-Agent Endpoint: Returns the User-Agent string from the request.
File Serving: Serves files from a specified directory. Supports GET and POST methods.
Gzip Compression: Supports gzip compression based on the Accept-Encoding header.

Usage

Starting the Server

To start the server, run the following command:

go run main.go [directory]

Directory (optional): The directory from which to serve files. If not specified, the current directory will be used.

Endpoints

Echo Endpoint

URL: /echo/{content}
Method: GET
Description: Returns the {content} appended to the URL.

User-Agent Endpoint

URL: /user-agent
Method: GET
Description: Returns the User-Agent string from the request.

File Serving

URL: /files/{filename}
Method:
- GET: Serves the specified file.
- POST: Saves the content in the request body to the specified file.
Description: Serves or saves files in the specified directory.

Example Requests

Echo Content:

curl http://localhost:4221/echo/hello

Response:

hello

Get User-Agent:

curl http://localhost:4221/user-agent

Response:

curl/7.68.0

Serve File:

curl http://localhost:4221/files/example.txt

Save File:

curl -X POST -H "Content-Type: text/plain" -d "This is a test" http://localhost:4221/files/example.txt

Implementation

Here's a brief overview of the code structure:

main.go: The main entry point of the server.
- main(): Starts the server and listens on the specified port.
- handleConnection(conn net.Conn): Handles incoming connections.
- parseRequest(conn net.Conn): Parses the HTTP request.
- getStatus(statusCode int, statusText string): Returns the HTTP status line.
- getDirectoryFromArgs(): Returns the directory from which to serve files, defaulting to the current directory if not specified.

Error Handling

Returns 400 Bad Request for malformed requests.
Returns 404 Not Found for unknown paths or missing files.
Returns 405 Method Not Allowed for unsupported methods.
Returns 500 Internal Server Error for server-side errors during file operations.

Gzip Compression

The server supports gzip compression if the Accept-Encoding header includes gzip. Compressed responses include the Content-Encoding: gzip header.