How to remove trailing whitespace of all files recursively?

Question

How can you remove all of the trailing whitespace of an entire project? Starting at a root directory, and removing the trailing whitespace from all files in all folders.

Answer 1

This is what works for me (Mac OS X 10.8, GNU sed installed by Homebrew):

find . -path ./vendor -prune -o \
  \( -name '*.java' -o -name '*.xml' -o -name '*.css' \) \
  -exec gsed -i -E 's/\t/    /' \{} \; \
  -exec gsed -i -E 's/[[:space:]]*$//' \{} \; \
  -exec gsed -i -E 's/\r\n/\n/' \{} \;

Removed trailing spaces, replaces tabs with spaces, replaces Windows CRLF with Unix \n.

What's interesting is that I have to run this 3-4 times before all files get fixed, by all cleaning gsed instructions.