       ctoken strvar separators
              Parse a token out of a character string.  The string to parse is
              contained in the variable named strvar.  The  string  separators
              contains all of the valid separator characters for tokens in the
              string.  All leading separators are skipped and the first  token
              is  returned.   The  variable strvar will be modified to contain
              the remainder of the string following the token.

              This command does not work with binary data.
