Homework for Embedded and Linux System Engineer Candidates
Our goal is to understand your knowledge of:
- Modern C++ (Especially resource management and object oriented design)
- Linux System programming
- Linux service management (systemd services)
- Linux development/build tools
Your task is to implement a Linux service that maintains a single current count and modifies the count by accepting commands over TCP/IP socket.
- Listen for count commands on TCP/IP socket port 8089.
- Command structures are ascii strings followed by CRLF
- Example: INCR 5\r\n
- The following counting commands are required:
- 'INCR ' : Increment the current count by integer amount
- 'DECR ' : Decrement the current count by integer amount
- 'OUTPUT' : Write the current count as an ascii string to the socket which requested it.
- For every count change, the current count should be written to each active connection.
- If the service receives a SIGTERM, it shall shutdown all of it's connections and exit with a 0 status code.
- Do NOT use 3rd party libraries like boost for this assignment
- The service shall be single threaded and support up to 1024 connections. (hint use epoll or select for asyncio).
- Explain (no need to implement) how this service could be integrated with systemd so that it will:
- Be restarted after a crash
- All output to stderr will be sent to the journal
Please provide a Makefile or CMakeLists.txt file that will build the service as the default target.
telnet or socat can be used for sending commands and receiving count updates.
telnet localhost 8089
Please create a separate github repository to implement this homework assignment and then send us a link when you are ready for us to review.
- Please do not fork or submit a PR to this repo
- Please document your thought-processes and use well-written git commit messages to show your progress
- This assignment should take less than 5 hours to complete
- If you get stuck or need more information, please reach out for clarity
- Have fun!