# A  Auxiliary files

Given an input TeX document whose main file is `story.tex`, the command

```tex2page story
```

typically produces at least one output HTML file `story.html`, and possibly some additional HTML files, which are named `story‑Z‑H‑1.html`, `story‑Z‑H‑2.html`, and so on. Additional HTML files are created whenever the input document has commands requesting page breaks in the HTML output.

This is about all you need to know. However, TeX2page does manipulate many other little auxiliary files in order to communicate information both to external programs and across successive runs of itself. The following briefly describes the functions of these auxiliary files, should you ever need to look at them more closely, either out of curiosity or for debugging your document.

TeX2page displays on standard output the log of its progress with `story.tex`. A copy of this log is kept in the log file `story.hlog`.

TeX2page generates a style sheet in `story‑Z‑S.css`. This contains some default style information that TeX2page generates for every document, plus any style info supplied by the user via `\cssblock` statements in the document.

If `story.tex` uses the external program BibTeX for its bibliography, TeX2page sends information to BibTeX in the file `story‑Z‑B.aux` and receives information from BibTeX in the file `story‑Z‑B.bbl`.

If `story.tex` contains `\index` commands, TeX2page will dump the unsorted index into `story‑Z‑I.idx` and get from MakeIndex the sorted index `story‑Z‑I.ind`.

TeX2page uses the auxiliary files `story‑Z‑L.scm` and `story‑Z‑A.scm` to keep track of labels and other internal cross-references. Each run of TeX2page loads the `story‑Z‑L.scm` and `story‑Z‑A.scm` created by the previous run. If `story.tex` contains forward cross-references, TeX2page must be rerun at least once.

For the image portions of `story.tex`, TeX2page creates the auxiliary TeX files `story‑Z‑G‑1.tex`, etc, and uses external programs (as described on p. 6) to convert them to the corresponding image files `story‑Z‑G‑1.gif`, etc. (This assumes you are using the GIF format for images. If you had requested the PNG or JPEG format for images, the extensions of these aux files would be correspondingly different.)

The above are ‘‘single-use’’ images. `story.tex` may reuse some image files within itself. Such image files have slightly different names and are numbered separately: `story‑Z‑G‑D‑1.gif`, etc.

Occurrences of `\eval` in `story.tex` typically create the auxiliary Scheme files `story‑Z‑E‑1.scm`, etc. These are converted (by Scheme) into the corresponding auxiliary TeX files `story‑Z‑E‑1.tex`, etc, which are loaded back into `story.tex` on a subsequent run. Only the `\eval`s that will be processed by TeX (i.e., those that are not in HTML-only regions, p. 2) produce such numbered auxiliary files, since the numbering allows successive runs of TeX to access the correct file. Such `\eval`s and their files can also be shared by TeX2page and TeX, without the `\eval`s that occur in the HTML-only portions throwing the numbering off. `\eval`s in HTML-only regions of the document are processed without any memorable aux files, because TeX won’t use them, and TeX2page (which, unlike TeX, can call Scheme immediately in the current run) doesn’t need them.

By default, all these files are created in the working directory. To avoid cluttering up your working directory, you can specify a different target directory using one of the following three files:

 1 `jobname.hdir` in the working directory, i.e., a file with the same basename as the input document but with extension `.hdir`. For `story.tex`, this would be `story.hdir`.

 2 `.tex2page.hdir` in the working directory.

 3 `.tex2page.hdir` in the user’s `HOME` directory.

The first line of the first of these files that exists is taken to be the name of the target directory. If none of these files exist, the current working directory is the target directory.

The `.hdir` file may contain the TeX control sequence `\jobname`, which expands to the basename of the input TeX document.