"how can I input a text file for text mining?"

Hi,
the best operator for your needs is the TextInput operator from the TextMining plugin. There you might specify a directory which is then searched for all files. Each file is imported as single example.

Greetings,
  Sebastian

Perhaps a silly question, but where is the TextInput operator in version 5.0?

Thanks!

Hi,
the TextInput operators have been replaced by the process documents operators.

Greetings,
  Sebastian