## 19.2 Format with `tex` and `texindex`

Format the Texinfo file with the shell command `tex` followed by the name of the Texinfo file. For example:

    tex foo.texi

TeX will produce a DVI file as well as several auxiliary files containing information for indices, cross references, etc. The DVI file (for DeVice Independent file) can be printed on virtually any device (see the following sections).

The `tex` formatting command itself does not sort the indices; it writes an output file of unsorted index data. (The `texi2dvi` command automatically generates indices; see section Format with `texi2dvi`.) To generate a printed index after running the `tex` command, you first need a sorted index to work from. The `texindex` command sorts indices. (The source file ‘`texindex.c`’ comes as part of the standard Texinfo distribution, among other places.)

The `tex` formatting command outputs unsorted index files under names that obey a standard convention: the name of your main input file with any ‘`.tex`’ (or similar, see tex invocation in Web2c) extension removed, followed by the two letter names of indices. For example, the raw index output files for the input file ‘`foo.texinfo`’ would be ‘`foo.cp`’, ‘`foo.vr`’, ‘`foo.fn`’, ‘`foo.tp`’, ‘`foo.pg`’ and ‘`foo.ky`’. Those are exactly the arguments to give to `texindex`.

Instead of specifying all the unsorted index file names explicitly, you can use ‘`??`’ as shell wildcards and give the command in this form:

    texindex foo.??

This command will run `texindex` on all the unsorted index files, including any that you have defined yourself using `@defindex` or `@defcodeindex`. (You may execute ‘`texindex foo.??`’ even if there are similarly named files with two letter extensions that are not index files, such as ‘`foo.el`’. The `texindex` command reports but otherwise ignores such files.)

For each file specified, `texindex` generates a sorted index file whose name is made by appending ‘`s`’ to the input file name. The `@printindex` command looks for a file with that name (see section Printing Indices and Menus). `texindex` does not alter the raw index output file.

After you have sorted the indices, you need to rerun the `tex` formatting command on the Texinfo file. This regenerates the DVI file, this time with up-to-date index entries.

Finally, you may need to run `tex` one more time, to get the page numbers in the cross-references correct.

To summarize, this is a five step process:

1. Run `tex` on your Texinfo file. This generates a DVI file (with undefined cross-references and no indices), and the raw index files (with two letter extensions).
2. Run `texindex` on the raw index files. This creates the corresponding sorted index files (with three letter extensions).
3. Run `tex` again on your Texinfo file. This regenerates the DVI file, this time with indices and defined cross-references, but with page numbers for the cross-references from last time, generally incorrect.
4. Sort the indices again, with `texindex`.
5. Run `tex` one last time. This time the correct page numbers are written for the cross-references.

Alternatively, it’s a one-step process: run `texi2dvi` (see section Format with `texi2dvi`).

You need not run `texindex` each time after you run `tex`. If you do not, on the next run, the `tex` formatting command will use whatever sorted index files happen to exist from the previous use of `texindex`. This is usually ok while you are debugging.

Sometimes you may wish to print a document while you know it is incomplete, or to print just one chapter of a document. In that case, the usual auxiliary files that TeX creates and warnings TeX gives when cross-references are not satisfied are just nuisances. You can avoid them with the `@novalidate` command, which you must give before the `@setfilename` command (see section `@setfilename`). Thus, the beginning of your file would look approximately like this:

    \input texinfo
    @novalidate
    @setfilename myfile.info
    …

`@novalidate` also turns off validation in `makeinfo`, just like its `--no-validate` option (see section Pointer Validation).

This document was generated on a sunny day using texi2html.