Explain what the hell is going on

README.md

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+#install via:
+git config --global init.templatedir '~/.git_template'
+
+So, this is a rudimentary set of git hooks which will incrementally update a tags file for your project under .git/tags on basically any branch change.
+
+This is basically directly inspired from @tpope's writeup http://tbaggery.com/2011/08/08/effortless-ctags-with-git.html on automating ctags with git.
+
+My only problem with that idea was that it has to regenerate the whole ctags file on every branch change.  With large repos, this can become a problem, and other attempts (search for inotify+ctags and the like) tend to have poor performance on large amounts of file changes.
+
+#Implementation
+OK, this is the ugly part.  We temporarily write and execute a C program to filter 'removed' files from your ctags, then feed the remainder of changed files as seen by git-diff into a ctags --append.  While this is incredibly ugly, it is orders of magnitude faster than awk/sed/perl, and about 10-20% faster than CPython on my tests involving an approximately 80MB tags file.
+
+#requirements
+
+ * git 1.7.1 or newer
+ * GCC (or a compatible frontend.)
+ * POSIX/BSDish libc (we use `hsearch()`)
+ * zsh or bash (i've attempted to make these scripts use your favorite shell to pull in your environment of choice, but I have not recently tested this stuff under bash.)
+ * logger which supports the -t argument, for syslog output
+
+#caveats
+You probably dont want to run this on untrusted repos -- magic characters in filenames could do bad things to you!  Also, I have only tested this on Linux and ZSH 5.0.5.