How to combine all txt in one folder into 1 file, while cleaning the contents of all txt without deleting the files themselves?

Question

File systems

Hello!
How to combine all txt in one folder into 1 file, while cleaning the contents (all txt) without deleting the files themselves?
Perhaps a batch file or a script will help.
Thanks:)

Answer 1

Let's say these files are in the dir directory. Then the command code (for Linux) will be:

find dir -name "*.txt" -exec sh -c 'cat \{} >> t.txt && :>\{}' \;