A third approach is to build an index in background under MultiFinder on the Macintosh. My program “MultIndexer” lets you do just that. It has the unæsthetic command-line UNIX-like interface that qndxr.c suffers from, but once you get it running, you can jump into another memory partition and keep working while the indexing proceeds for you. MultIndexer is usually a bit slower than the other index-building programs, since it doesn't get as much processor time in background and has to work in a smaller memory space. (MultIndexer can run in as little as 160 kB.) If you need to do something else while a large file is being indexed, MultIndexer may be the solution.
Both qndxr.c and MultIndexer are free programs. See the comments on distribution for information about places to get qndxr.c and MultIndexer.