A Command Line Based tool that checks the status of URLs passed as arguements
- os
- fmt
NOTE: The below step-wise plan is for my understanding and structure. Feel free to use it :)
Step 1: CLI Argument Handling
Hint: You’ll find what you need in the os package. Don’t forget that the first element is always the command itself. Validate input length.
Checkpoint: Can your program reject empty input and print usage instructions?
Step 2: HTTP Request Logic
Hint: A standard library package lets you make a GET request with one line. Handle possible errors (what if the domain doesn't exist?). Time the request — think of what tool gives you nanosecond precision.
Checkpoint: Can you extract status code, status string, and duration in milliseconds?
Step 3: Result Struct
Hint: You'll eventually have multiple fields like status, duration, etc. Bundle them. Think: how would you return more than one thing from a function?
Checkpoint: Can you return a full "result object" from your checker logic?
Step 4: Print Clean Output
Hint:
Basic fmt.Printf will get you started. Want colored output? Dig into ANSI escape codes or third-party CLI packages — but make it optional.
Checkpoint: Does your output make success and failure obvious at a glance?
Step 5: Concurrency
Hint:
You want to check multiple URLs without waiting for each. Use goroutines — but how will you collect the results in a safe way? Channels. Don’t forget to close them after.
Also, beware of race conditions and lost results.
Checkpoint: Can you check 5 URLs in parallel and get 5 results printed?
Step 6: Add Timeout
Hint:
http.Get() is too simplistic. You need control. What alternative gives you access to timeout and redirect handling?
You’ll also want to make the timeout configurable via CLI flag.
Checkpoint: Does your program fail fast on a dead URL with a user-defined timeout?
Step 7: Add Flags
Hint:
Check out the flag package. Support a --timeout or -t. Start small. Avoid overengineering.
Checkpoint: Can the user run your tool like ./checker -t 2s https://example.com?
Step 8: File Input (Optional)
Hint:
Read a file line by line. You’ll need os.Open and a scanner from the bufio package. Trim each line before use.
Checkpoint: Can you load 100 URLs from a file and process them?
Step 9: Polishing
- Is your output clean under stress?
- Do you handle invalid URLs?
- Do you measure response time accurately?
- Can you ship a binary with go build?
Step 10: Extra Challenges (Optional)
- Add JSON export via --output
- Retry failed checks
- Write unit tests
- Add spinner or progress display
- Limit concurrency with worker pool (bonus: use semaphore pattern)