What are common Hydra command-line options?

Here are some common command-line options for Hydra that you can use to customize your brute-force attacks:

-l: Specify a single username.
```
-l username
```
-L: Specify a file containing a list of usernames.
```
-L usernames.txt
```
-p: Specify a single password to test.
```
-p password
```
-P: Specify a file containing a list of passwords.
```
-P passwords.txt
```
-t: Set the number of parallel tasks (threads) to use.
```
-t 4
```
-s: Specify a custom port if the service is running on a non-standard port.
```
-s 2222
```
-v: Enable verbose mode for more detailed output.
```
-v
```
-vV: Enable very verbose mode for extensive output.
```
-vV
```
-f: Exit after the first found password.
```
-f
```
-e: Specify additional passwords to try (e.g., -e ns for null and space).
```
-e ns
```
-o: Output results to a specified file.
```
-o results.txt
```
-h: Display help and usage information.
```
-h
```

Here’s an example of a command using several options:

hydra -L usernames.txt -P passwords.txt -t 8 -vV ssh://192.168.1.1

Always ensure you have permission to test the systems you are targeting, as unauthorized access is illegal.

If you have any specific scenarios or need further clarification on any options, feel free to ask!