# Generate only aux file for external files

I use an external document by both \input-ting it and cross-referecing labels. It looks a bit like this:

\zexternaldocument*{external}
In picture \ref{external-link}, you see ...
\input{external}


However, I get lots of xr warnings like:

Package zref-xr Warning: File external' not found or empty, labels not imported


So I think I need to run latex/pdflatex to create them. However, I don't want to make full pdfs off the external files (this would fail since they don't even include any packages - they are already as put in after \begin{document}). So can I generate only .aux-files for each external document?

Has someone a solution for Linux from shell (no GUI, please)?

• I don't understand the question. If you input the tex file it is not an external document. So why don't you use \ref{link}? – Ulrike Fischer Oct 25 '14 at 10:35
• @UlrikeFischer oh yes, it suffices to simply use \input without any external documents - many thanks. – Johannes Oct 25 '14 at 11:01
• in your case you do not need it at all as you are inputting the files, but the answer to the question as written is basically no, especially for \pagreref you really need to typeset the external file to know what numbers should be written to the aux file. – David Carlisle Oct 25 '14 at 11:52

The zref package is not required, as you can input the source of the document you want to reference (\input{external}).
Just use \ref{label}`.