automatic setting of mode

[?manu*]

I know that it is possible to write some comments at the beginning of
a file, to tell emacs to open the file with a specified mode. For
example I use the line:

-*- mode: html; -*-

in some files that I would like to edit in HTML mode (even if they
don't have the html extension).

Now I wonder If there is a similar command to get the following:

1. automatically issuing the command
M-x tex-pdf
which tells emacs to compile a LaTeX file with pdflatex.

2. automatically issuing the command
M-x set-buffer-file-coding-system utf-8
telling emacs that the file is encoded in utf8

thank you for any help

E.