Call the doc_cache_base function to obtain the base file name that will be used to identify cache files when the document is formatted. If the optional parameter doc is omitted, the current document is used.

If this function were to return the path and base file name /tmp/aptcache/demo000/xyz, then the format command will produce formatting files using the base file name xyz. For example, formatting files would be named /tmp/aptcache/demo000/xyz.dvi, /tmp/aptcache/demo000/xyz.tex, and so on.