web2c: Creating memory dumps
4.3.1 Creating memory dumps
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The programs all create memory dumps in slightly idiosyncratic (thought
substantially similar) way, so we describe the details in separate
sections (references below). The basic idea is to run the initial
version of the program (⇒Initial and virgin), read the source
file to define the macros, and then execute the '\dump' primitive.
Also, each program uses a different filename extension for its memory
dumps, since although they are completely analogous they are not
interchangeable (TeX cannot read a Metafont memory dump, for example).
Here is a list of filename extensions with references to examples of
creating memory dumps:
TeX
('.fmt') ⇒Initial TeX Initial TeX.
Metafont
('.base') ⇒Initial Metafont.
When making memory dumps, the programs read environment variables and
configuration files for path searching and other values as usual. If
you are making a new installation and have environment variables
pointing to an old one, for example, you will probably run into
difficulties.