How to know how many files are there recursively in a folder?
The answer to that questions is easy to answer with this command.
find [YOUR_FOLDER] -type f ¦ wc -l
If you want to start in the current folder the command is:
find . -type f ¦ wc -l
And if you want a specific type of file, you can use:
find . -type f -name "*.txt" ¦ wc -l
In that case it will count all files with txt extension that are in the current folder and its sub-folders.