Usage
Author: Luc Maranget

## C.1 Usage

- HEVEA usage
- HACHA usage
- esponja usage
- bibhva usage
- imagen usage
- Invoking hevea, hacha and imagen
- Using make

### C.1.1 HEVEA usage

The hevea command has two operating modes, normal mode and filter mode. Operating mode is determined by the nature of the last command-line argument.

#### C.1.1.1 Command line arguments

The hevea command interprets its arguments as names of files and attempts to process them. Given an argument filename there are two cases:

- If filename is base.tex or base.hva, then a single attempt to open filename is made.
- In other cases, a first attempt to open filename.tex is made. In case of failure, a second attempt to open filename is made.

In all attempts, implicit filenames are searched along hevea search path, which consist in:

1. the current directory “.”,
2. user-specified directories (with the -I command-line option),
3. hevea library directory.
4. one of the sub-directories html, text or info from hevea library directory, depending upon hevea output format,

The hevea library directory is fixed at compile-time (this is where hevea library files are installed) and typically is /usr/local/lib/hevea. However, this compile-time value can be overridden by setting the HEVEADIR shell environment variable. In all cases, the value of hevea library directory can be accessed from the processed document as the value of the command `\@hevealibdir`.

#### C.1.1.2 Normal mode

If the last argument has an extension that is different from .hva or has no extension, then it is interpreted as the name of the main input file. The main input file is the document to be translated and normally contains the `\documentclass` command. In that case two basenames are defined:

- The input basename, basein, is defined as the main input file name, with extension removed when present.
- The output basename, baseout, is basein with leading directories omitted. However the output basename can be changed, using the `-o` option (see below).

HEVEA will attempt to load the main input file. Ancillary files from a previous run of LATEX (i.e. .aux, .bll and .idx files) will be searched as basein`.`ext. The output base name governs all files produced by HEVEA. That is, html output of HEVEA normally goes to the file baseout.html, while cross-referencing information goes into baseout.haux. Furthemore, if an image file is generated (cf. section 6), its name will be baseout.image.tex.

Thus, in the simple case where the hevea command is invoked as:

    # hevea file.tex

The input basename is file and the output basename also is file. The main input file is searched once along hevea search path as file.tex. html output goes into file file.html, in the current directory. In the more complicated case where the hevea command is invoked as:

    # hevea ./dir/file

The input base name is ./dir/file and the output basename is file. The main input file is loaded by first attempting to open file ./dir/file.tex, then file ./dir/file. html output goes into file file.html, in the current directory.

Finally, the output base name can be a full path, but you have to use option -o. For instance, we consider:

    # hevea -o out/out.html file.tex

Then, html output goes into out/out.html — notice that directory out must exist. Furthermore, hevea output base name is out/out. This means that hevea generates files out/out.haux, out/out.image.tex etc.

The article.hva, seminar.hva, book.hva and report.hva base style files from HEVEA library are special. Only the first base style file is loaded and the `\documentclass` command has no effect when a base style file is already loaded. This feature allows to override the document base style. Thus, a document file.tex can be translated using the article base style as follows:

    # hevea article.hva file.tex

#### C.1.1.3 Filter mode

If there is no command-line argument, or if the last command-line argument has the extension .hva, then there is neither input base name nor output base name, the standard input is read and output normally goes to the standard output. Output starts immediately, whithout waiting for `\begin{document}`. In other words hevea acts as a filter.

Please note that this operating mode is just for translating isolated LATEX constructs. The normal way to translate a full document file`.tex` being “`hevea` file`.tex`” and not “`hevea <` file`.tex >` file`.html`”.

#### C.1.1.4 Options

The hevea command recognises the following options:

-version
  Show hevea version and exit.
-v
  Verbose flag, can be repeated to increase verbosity. However, this is mostly for debug.
-dv
  Add border around some of the block-level elements issued. Specifically, all `div` and `p` are bordered, while the structure of displayed material is also shown.
-s
  Suppress warnings.
-I dirname
  Add dirname to the search path.
-o name
  Make name the output basename. However, if name is base.html, then the output basename is base. Besides, -o - makes HEVEA output to standard output.
-e filename
  Prevent hevea from loading any file whose name is filename. Note that this option applies to all files, including hevea.hva and base style files.
-fix
  Iterate HEVEA until a fixpoint is found. Additionally, images get generated automatically.
-O
  Optimise html by calling esponja (see section C.1.3).
-exec prog
  Execute file prog and read the output. The file prog must have execution permission and is searched by following the searching rules of hevea.
-francais
  Deprecated by babel support. This option issues a warning message.
-help
  Print version number and a short help message.

The following options control the html code produced by hevea. By default, hevea outputs a page encoded in US-ASCII with most symbols rendered as html or numerical Unicode entities.

-entities
  Render symbols by using entities. This is the default.
-textsymbols
  Render symbols by English text.
-moreenties
  Enable the output of some infrequent entities. Use this option to target browsers with wide entities support.
-mathml
  Produces MathML output for equations, very experimental.
-pedantic
  Be strict in interpreting html definition. In particular, this option disable size and color changes inside `<PRE>`… `</PRE>`, which are otherwise performed.

The following options select and control alternative output formats (see section 11):

-text
  Output plain text. Output file extension is .txt.
-info
  Output info format. Output file extension is .info.
-w width
  Set the line width for text or info output, defaults to 72.

Part A of this document is a tutorial introduction to HEVEA, while Part B is the reference manual of HEVEA.

### C.1.2 HACHA usage

The hacha command interprets its argument base.html as the name of a html source file to cut into pieces.

It also recognises the following options:

-v
  Be a little verbose.
-o filename
  Make HACHA output go into file filename (defaults to index.html). Additionally, if filename is a composite filename, dir/base, then all files outputted by HACHA will reside in directory dir.
-tocbis
  Another style for table of contents: sub-tables are replicated at the beginning of every file.
-tocter
  Like -tocbis above, except that sub-tables do not appear in the main table of contents (see Section 7.2.3).
-no-svg-arrows
  Use GIF arrows for the Previous/Up/Next links, in place of the default SVG arrows.
-nolinks
  Do not insert Previous/Up/Next links in generated pages.
-hrf
  Output a base.hrf file, showing in which output files are the anchors from the input file gone. The format of this summary is one “anchor`\t`file” line per anchor. This information may be needed by other tools.
-help
  Print version number and a short help message.

Section 7 of the user manual explains how to alter HACHA default behaviour.

### C.1.3 esponja usage

The program esponja is part of HEVEA and is designed to optimise hevea output. However, esponja can also be used alone to optimise text-level elements in html files. Since esponja fails to operate when it detects incorrect html, it can be used as a partial html validator.

#### C.1.3.1 Operating mode

The program esponja interprets its arguments as names of files and attempt to process them. It is important to notice that esponja will replace files by their optimised versions, unless instructed not to do so with option -n.

Invoking esponja as

    # esponja foo.html

will alter foo.html. Of course, if esponja does not succeed in making foo.html any smaller or if esponja fails, the original foo.html is left unchanged. Note that this feature allows to optimise all html files in a given directory by:

    # esponja *.html

#### C.1.3.2 Options

The command esponja recognises the following options:

-v
  Be verbose, can be repeated to increase verbosity.
-n
  Do not alter input files. Instead, esponja output for file input.html goes to file input.esp. Option -n implies option -v.
-u
  Output esponja intermediate version of html. In most occasions, this amounts to pessimize instead of to optimise. It may yield challenging input for other html optimisers.

### C.1.4 bibhva usage

The program bibhva is a simple wrapper, which basically forces bibtex into accepting a .haux file as input and producing a .hbbl file as output. Usage is bibhva bibtex-options basename.

### C.1.5 imagen usage

The command imagen is a simple shell script that translates a LATEX document into many .png images. The imagen script relies on much software to be installed on your computer, see Section C.4.1.

It is a companion program of HEVEA, which must have been previously run as:

# hevea… base.tex
or
# hevea… -o base.html…

In both cases, base is HEVEA output basename. When told to do so (see section 6) HEVEA echoes part of its input into the base.image.tex file.

The imagen script should then be run as:

# imagen base

The imagen script produces one basennn.png image file per page in the base.image.tex file.

This is done by first calling latex on base.image.tex, yielding one dvi file. Then, dvips translates this file into one single Postscript file that contains all the images, or into one Postscript file per image, depending upon your version of dvips. Postscript files are interpreted by ghostscript (gs) that outputs ppm images, which are then fed into a series of transformations that change them into .png files.

The imagen script recognises the following options:

-mag nnnn
  Change the enlarging ratio that is applied while translating DVI into Postscript. More precisely, dvips is run with -xnnnn option. Default value for this ration is 1414, this means that, by default, imagen magnifies LATEX output by a factor of 1.414.
-extra command
  Insert command as an additional stage in imagen ppm to png production chain. command is an Unix filter that expects a ppm image in its standard input and outputs a ppm image on its standard output. A sensible choice for command is one command from the netpbm package, several such commands piped together, or various invocations of the convert command from ImageMagick.
-quant number
  Add an extra color quantisation step in imagen ppm image production chain, where number is the maximal number of colors in the produced images. This option may be needed as a response to a failure in the image production chain. It can also help in limiting image files size.
-png
  Output PNG images. This is the default.
-gif
  Output GIF images in place of PNG images. GIF image files have a .gif extension. Note that hevea should have been previously run as hevea gif.hva base.tex (so that the proper .gif filename extension is given to image file references from within the html document).
-svg
  Output SVG images in addition to PNG (or GIF) images. Note that hevea should have been previously run as hevea svg.hva base.tex.
-pnm
  Output PPM images. This option mostly serves debugging purposes. Experimented users can also take advantage of it for performing additional image transformation or adopting exotic image formats.
-t arg
  Pass option “-t arg” to dvips. For instance, using “-t a3” may help when images are truncated on the right.
-pdf
  Have imagen call pdflatex instead of latex.

The first three options enable users to correct some misbehaviours. For instance, when the document base style is seminar, image orientation may be wrong and the images are too small. This can be cured by invoking imagen as:

# imagen -extra "pnmflip -ccw" -mag 2000 base

Notice that hevea calls imagen by itself, when given the command-line option -fix. In that situation, the command-line options of imagen can be controlled from source file by using the command `\@addimagenopt` (see Section 10.7).

### C.1.6 Invoking hevea, hacha and imagen

In this section, we give a few sequence of (Unix) commands to build the html version of a document in various situations. The next section gives a few Makefile’s for similar situations.

We translate a file doc.tex that requires a specific style file doc.hva. The file is first translated into doc.html by hevea, which also reads the specific style file doc.hva. Then, hacha cuts doc.html into several, doc001.html, doc002.html, etc. also producing the table of links file index.html.

    # hevea -fix doc.hva doc.tex
    # hacha doc.html

Thanks to the command-line option -fix, hevea runs the appropriate number of times automatically. In case hevea produces a non-empty doc.image.tex file, then hevea calls imagen by itself (because of option -fix). Hence, the above sequence of two commands is also appropriate in that situation.

In case some problem occurs, it is sometime convenient to run imagen by hand. It is time not to use the option -fix.

    # rm -f doc.image.tex
    # hevea doc.hva doc.tex

Now, hevea normally has shown the imagen command line that it would have run, if it had been given the option -fix. For instance, if doc.hva includes `\input{gif.hva}`, then hevea shows the following warning:

    HeVeA Warning: images may have changed, run 'imagen -gif doc'

Now, one can run imagen as it should be.

It is sometime convenient not to clobber the source directory with numerous target files. It suffices to instruct hevea and hacha to output files in a specific directory, say doc.

    # hevea -fix -o doc/doc.html doc.hva doc.tex
    # hacha -o doc/index.html doc/doc.html

Notice that hevea does not create the target directory doc: it must exist before hevea runs. Again, in case hevea calls imagen, image generation should proceed smoothly and the final files doc001.png, doc002.png, … should go into directory doc.

In all situations, while installing files to their final destination, it is important not to forget any relevant files. In particular, in addition to the root file (index.html), contents files (doc001.html, doc002.html, etc.) and images (doc001.png, doc002.png, etc.), one should not forget the arrow images and the style sheet generated by hacha (contents_motif.gif, next_motif.gif, previous_motif.gif and doc.css).

As a consequence, producing all files into the subdirectory doc may be a good idea, since then one easily install all relevant files by copying doc to a public destination.

    # cp -r doc $(HOME)/public_html

However, one then also installs the auxiliary files of hevea, and hevea output file doc.html, which is no longer useful once hacha has run. Hence, those should be erased beforehand.

    # rm -f doc/doc.h{tml,aux,ind,toc} doc/doc.image.tex
    # cp -r doc $(HOME)/public_html

### C.1.7 Using make

Here is a typical Makefile, which is appropriate when no images are produced.

    HEVEA=hevea
    HEVEAOPTS=-fix
    HACHA=hacha
    #document base name
    DOC=doc
    index.html: $(DOC).html
            $(HACHA) -o index.html $(DOC).html

    $(DOC).html: $(DOC).hva $(DOC).tex
            $(HEVEA) $(HEVEAOPTS) $(DOC).hva $(DOC).tex

    clean:
            rm -f $(DOC).html $(DOC).h{toc,aux,ind}
            rm -f index.html $(DOC)[0-9][0-9][0-9].html $(DOC).css

Note that the clean rule removes all the doc001.html, doc002.html, etc. and doc.css files produced by hacha. Also note that make clean also removes the doc.haux, doc.hind and doc.htoc files, which are HEVEA auxiliary files.

When the image file feature is used, one can use the following, extended, Makefile:

    HEVEA=hevea
    HEVEAOPTS=-fix
    HACHA=hacha
    #document base name
    DOC=doc
    index.html: $(DOC).html
            $(HACHA) -o index.html $(DOC).html

    $(DOC).html: $(DOC).hva $(DOC).tex
            $(HEVEA) $(HEVEAOPTS) $(DOC).hva $(DOC).tex

    clean:
            rm -f $(DOC).html $(DOC).h{toc,aux,ind}
            rm -f index.html $(DOC)[0-9][0-9][0-9].html $(DOC).css
            rm -f $(DOC).image.* $(DOC)[0-9][0-9][0-9].png *_motif.gif

Observe that the clean rule now also gets rid of doc.image.tex and of the various files produced by imagen.

With the following Makefile, hevea, imagen, hacha all output their files into a specific directory DIR.

    HEVEA=hevea
    HEVEAOPTS=-fix
    HACHA=hacha
    #document base name
    DOC=doc
    DIR=$(HOME)/public_html/$(DOC)
    BASE=$(DIR)/$(DOC)

    $(DIR)/index.html: $(BASE).html
            $(HACHA) -tocter -o $(DIR)/index.html $(BASE).html

    $(BASE).html: $(DOC).hva $(DOC).tex
            $(HEVEA) $(HEVEAOPTS) $(DOC).hva -o $(BASE).html $(DOC).tex

    partialclean:
            rm -f $(BASE).h{tml,aux,toc,ind} $(BASE).image.*

    clean:
            rm -f $(DIR)/*

The above Makefile directly produces html and PNG files into the final directory `$(HOME)/public_html/$(DOC)`. The new partialclean entry erases files that are not useful anymore, once imagen and hacha have performed their tasks.

However, most often, it is more appropriate to build html and PNG files in a specific directory, and then to copy them to their final destination.

       ...

    #document base name
    DOC=doc
    DIR=$(DOC)
    BASE=$(DIR)/$(DOC)
    INSTALLDIR=$(HOME)/public_html/$(DOC)

      ...

    install: partialclean
            cp $(DIR)/* $(INSTALLDIR)
      ...