Recursive deletes

Posting this little ruby snippet so i can reference it later. Need to recursively delete directories with a certain name in a large tree? The simplest example is scrubbing those pesky .svn directories in a subversion repository, which can be done like so:

require ‘fileutils’
Dir.glob(“**/.svn/”) {|fname| FileUtils.rm_r(fname) }

another use case I have here at work is to scrub extra maven generated versions of code out of each java project (so as to keep eclipse sane). In this case, we want to delete all directories (and their contents) named “target” except for the target directory at the root (because mvn clean is “too clean” in this instance):

require ‘fileutils’
Dir.glob(“**/target/”) {|fname| FileUtils.rm_r(fname) unless /^target.*/ =~ fname}

It gets a bit more complicated if you want to exclude list of directories from the operation. Here I found Ruby’s Enumerable module detect method quite handy to short circuit evaluate all the directories to exclude regex on each directory.


require 'fileutils'
@exclude= [/^foo.*/ , /^bar.*/ , /^james.*/, /^target.*/]
Dir.glob("**/target/") do |fname|
@erase = @exclude.detect{ |r| r =~ fname }.nil?
if @erase
puts "erasing #{fname}"
FileUtils.rm_r(fname)
else
puts "skipping #{fname}"
end
end

Note: this code won’t copy and paste well because wordpress replaces quotes with smartquotes. I also really need to fix my stylesheet for code samples.