Changing TEXMF run-time parameters
| Chapter 5. Advanced Topics |

## Changing TEXMF run-time parameters

You can control a number of run-time parameters (in particular, array sizes) on the command-line or in a configuration file.

Some of the more interesting paramaters:

main_memory

  Total words of memory available, for TeX, METAFONT, and MetaPost. You must remake the format file after changing (see the section called “Managing Memory Dump Files”).

extra_mem_bot

  Extra space for large TeX data structures: boxes, glue, breakpoints, et al.

font_mem_size

  Words of font info available for TeX.

See Chapter 10, TEXMF Run-Time Parameters, for a complete list of the TEXMF run-time parameters.

Here is a typical example of a configuration file:

    main_memory=2000000
    extra_mem_bot=2000000
    font_mem_size=2000000

The name of the configuration file is that of the engine (e.g., pdftex) or format (e.g, pdflatex). You use the `--edit-config-file` option of initexmf to edit the configuration file, e.g.:

    > initexmf --edit-config-file=pdflatex

    >

Managing Memory Dump Files |  | Part II. Reference