Fast code grepper

In preliminary tests, this appears to run about ten times as fast as Ack. This is my attempt at a programming grep tool that is as fast as possible.

Indexing is done on triplets of ASCII characters. These are used to build a search tree for each directory in the code base, which becomes a hidden subdirectory called ".codegrep.index". The contents of this subdirectory are a list of the files searched, and the search tree split out into individual files by the decimal ASCII value of first character.

To use this, do the following.

• Put cgrep in your path.
• Set the environment variable CODEGREPROOT to the root of the directory tree you want to search.
• Run build_c.sh to build a C module that accelerates the indexer.
• Run indexer.py to index the files to be searched. For a large code base this is going to take some time.
• Now you can do searches like this:

cgrep foobar