>>106991991
Sorry forgot, the arrow, so it works now, the best part about Lean is that i can use #eval to evaluate most functions on the fly without need to compile or go to REPL.
def read_file (file_path : String) : IO Unit := do
let io IO.getStdout
let path_to_file := System.FilePath.mk file_path
if (path_to_file.pathExists) then
let handle IO.FS.Handle.mk path_to_file IO.FS.Mode.read
io.putStrLn (handle.readToEnd)
else
io.putStrLn s!"Specified file: {file_path} does not exist!"
pure ()