# [OS X TeX] The `%!TEX TSprogram = TeXify' line used in TeXShop ...

Maarten Sneep maarten.sneep at xs4all.nl
Thu Feb 14 08:58:22 EST 2008

```John Dann schreef:
> Can anyone explain to me the use of these %! commands anyway?
>
> I've used TeXShop for a few years and never used them.
>
> Specifying the file encoding seems unnecessary to me as there are many
> ways in Cocoa to find out the encoding of a file, are they used by LaTeX
> or TeX at all?

Recognizing unicode is possible, recognising 8 bit encodings is not
possible, not reliable anyway. For TeX itself you use
\usepackage[utf8]{inputenc}, and it would be good if TeXShop recognizes
this.

There are several other settings that can be specified with %! like the
default command to process the file, the file which contains the
\documentclass - or at least where processing should start.

TeX itself knows nothing about Cocoa, so for TeX you need another method.
However, as far as TeX is concerned the %! commands are just comments, and
won't be used by TeX. It is just TeXShop which uses them.

Maarten

```