# Compilation of main tex file from a chapter file with AucTeX

I have a main LaTeX file that has multiple chapter files included using `\input` command. For compiling them in emacs/auctex, I have to open main LaTeX and `^C^C`.

How can I compile the main LaTeX from a chapter file?

I don't know exactly what happened, but I had to use `^C _` to specify the master file.

https://stackoverflow.com/questions/2199463/emacs-auctex-run-command-on-file-that-is-not-currently-open

• The reason it didn't work when you did it manually is that the variable only takes effect when you reopen the buffer. You could save the file and then do `revert-buffer` to reload it. Mar 27, 2020 at 18:10

Add at the end of each chapter file

``````%%% Local Variables:
%%% mode: latex
%%% TeX-master: "THEMAINFILE"
%%% End:
``````

to point AUCTeX to the main file. Furthermore, (quoting the AUCTeX manual)

if you often use `\include` or `\input`, you should make AUCTeX aware of the multi-file document structure. You can do this by inserting `(setq-default TeX-master nil)` into your init file. Each time you open a new file, AUCTeX will then ask you for a master file.

Or, if you usually use the same master filename

You should always set this variable to the name of the top level document. If you always use the same name for your top level documents, you can set TeX-master in your `.emacs` file.

`(setq-default TeX-master "master") ; All master files called "master".`