title: Search ill encoded characters in a file on Linux
body: <p>I have a lot of huge CSV files, some of them contain ill encoded characters: in vi, I see things like "&lt;8f>" or "&lt;8e>", for example.
  First, I wanted to search and replace (:%s) all the characters, but it will be a very long process because I will have to do this everytime I have to handle a file, and I'm not always sure whether new characters are here.
  Is it possible to detect such characters, so that I can extract lines containing ill encoded characters?
  A simple command may exist, taking a file for argument and creating a file containing only the lines with a problem.</p>
  
  <p>I don't know if I explain me very well...
  Thanks in advance! </p>