web2c: Runtime options

 
 2.5 Runtime options
 ===================
 
 Besides the configure- and compile-time options described in the
 previous sections, you can control a number of parameters (in
 particular, array sizes) in the 'texmf.cnf' runtime file read by
 Kpathsea (See(kpathsea)Config files).
 
    Rather than exhaustively listing them here, please see the last
 section of the distributed 'kpathsea/texmf.cnf'.  Some of the more
 interesting values:
 
 'main_memory'
      Total words of memory available, for TeX, Metafont, and MetaPost.
      Must remake the format file after changing.
 
 'extra_mem_bot'
      Extra space for "large" TeX data structures: boxes, glue,
      breakpoints, et al.  If you use PiCTeX, you may well want to set
      this.
 
 'font_mem_size'
      Words of font info available for TeX; this is approximately the
      total size of all TFM files read.
 
 'hash_extra'
      Additional space for the hash table of control sequence names.
      Approximately 10,000 control sequences can be stored in the main
      hash table; if you have a large book with numerous
      cross-references, this might not be enough, and thus you will want
      to set 'hash_extra'.
 
    Of course, ideally all arrays would be dynamically expanded as
 necessary, so the only limiting factor would be the amount of swap space
 available.  Unfortunately, implementing this is extremely difficult, as
 the fixed size of arrays is assumed in many places throughout the source
 code.  These runtime limits are a practical compromise between the
 compile-time limits in previous versions, and truly dynamic arrays.  (On
 the other hand, the Web2c BibTeX implementation does do dynamic
 reallocation of some arrays.)