driver

Driving the Translation of Pictures

Tex4ht outputs a script file (`.lg') describing how the dvi file (extension `.ivd') of pictures should be processed. In the default setting, the script file holds abstract commands of the following form.

--- needs --- source.ivd[i] ==> target.gif ---: An abstract command of this form requests that the i'th page in the dvi file will be translated into target file whose name is provided.
--- characters ---: This abstract command is a comment line identifying the pictorial characters.

A manual brute-force execution of the abstract commands can be a tedious job for large number of pictures. I use a perl script to interpret the abstract commands on a unix platform, and similar interpreters can be designed for other platforms. Another possible approach for automating the process is to request lg scripts in the form of shell scripts or batch files.

Alternatives to `--- needs --- source.ivd[i] ==> target.gif ---'

The default setting is made with a request of the form `--- needs --- %%1.ivd[%%2] ==> %%3.gif ---', where the parameters %%1, %%2, and %%3 respectively represent the name of the source file without its extension, a page number, and a name of the target file. Alternative patterns to these abstract commands can be requested in the following locations, with the order reflecting on the priority given to the requests.

In the command line of tex4ht, where the pattern should be prefixed with `-s'.
In the environment file `tex4ht.env' within a block of consecutive lines, where the lines should be identified with the character `s'.
In tex4ht with the pattern provided through the variable LGPIC of `tex4ht.c'.

The character `%' can be introduced into a pattern through the entry `%%%'. On the other hand, the parameters `%%1', `%%2', and `%%3' can specify, between the first two percentage characters (i.e., `%...%1', `%...%2', and `%...%3'), any format for the outcome that is compatible with the print formats of C.

Alternatives to `--- characters ---'

Substitutions for this abstract command can be requested in the following locations.

In the command line of tex4ht, prefixed with `-b'.
In a line within the environment file `tex4ht.file', where the line should be identified with the character `b'.
In tex4ht with the substitution provided during compilation time through the variable LGSEP of `tex4ht.c'.