FLASK_23_EXPERIMENTAL.py

import os
from flask import Flask, render_template, request, send_file, redirect

app = Flask(__name__)

# Define the directory for storing uploaded files
UPLOAD_DIRECTORY = os.path.join(os.getcwd(), "uploads")

# Set the maximum content length allowed for file uploads (e.g., 1 GB)
app.config['MAX_CONTENT_LENGTH'] = 1 * 1024 * 1024 * 1024

@app.route("/")
def index():
    # Get a list of all files in the upload directory
    files = os.listdir(UPLOAD_DIRECTORY)
    # Render the HTML template with the list of files
    return render_template("index.html", files=files)

@app.route("/upload", methods=["POST"])
def upload():
    # Get the uploaded file from the request
    uploaded_file = request.files["file"]

    # Check the mimetype of the uploaded file
    if uploaded_file.mimetype == 'text/plain':
        # Save the file to the upload directory using a streaming approach
        filename = uploaded_file.filename
        file_path = os.path.join(UPLOAD_DIRECTORY, filename)
        with open(file_path, "wb") as f:
            chunk_size = 4096  # Read and write 4KB at a time
            while (chunk := uploaded_file.stream.read(chunk_size)) :
                f.write(chunk)

        # Return a success message
        return "File uploaded successfully"
    else:
        # Return an error message if the file type is not allowed
        return "Invalid file type. Only 'text/plain' files are allowed.", 400

@app.route("/download/<filename>")
def download(filename):
    # Construct the path to the file
    path = os.path.join(UPLOAD_DIRECTORY, filename)
    # Send the file to the client for download
    return send_file(path, as_attachment=True)

if __name__ == "__main__":
    # Create the upload directory if it does not exist
    if not os.path.exists(UPLOAD_DIRECTORY):
        os.makedirs(UPLOAD_DIRECTORY)
    app.run(host="0.0.0.0", port="8000", debug=True)