module ExpectStr:sig..end
    This module extends Expect.expect to also handle Str regular
    expression. You can use `Regexp to provide the Str.regexp.
open Expect
open ExpectStr
let (), _ =
  with_spawn "ls" [| "-alh" |]
  (fun t () ->
    if expect t [`Regexp (Str.regexp "\\."), true] false then
      prerr_endline "'.' found")
  ()
val expect : Expect.t ->
       ?fmatches:(string -> 'a option) list ->
       ([< `Contains of string
         | `Eof
         | `Exact of string
         | `Fun of string -> bool
         | `Prefix of string
         | `Regexp of Str.regexp
         | `Suffix of string
         | `Timeout ] *
        'a)
       list -> 'a -> 'aExpect.expect.