Rack::File serves files below the root
directory given, according to the path info of the Rack request. e.g. when ::new(“/etc”) is used, you can access
‘passwd’ file as localhost:9292/passwd
Handlers can detect if bodies are a Rack::File, and
use mechanisms like sendfile on the path
.
# File lib/rack/file.rb, line 20 def initialize(root) @root = root end
# File lib/rack/file.rb, line 30 def _call(env) @path_info = Utils.unescape(env["PATH_INFO"]) return forbidden if @path_info.include? ".." @path = F.join(@root, @path_info) begin if F.file?(@path) && F.readable?(@path) serving else raise Errno::EPERM end rescue SystemCallError not_found end end
# File lib/rack/file.rb, line 24 def call(env) dup._call(env) end
# File lib/rack/file.rb, line 84 def each F.open(@path, "rb") { |file| while part = file.read(8192) yield part end } end
# File lib/rack/file.rb, line 47 def forbidden body = "Forbidden\n" [403, {"Content-Type" => "text/plain", "Content-Length" => body.size.to_s, "X-Cascade" => "pass"}, [body]] end
# File lib/rack/file.rb, line 76 def not_found body = "File not found: #{@path_info}\n" [404, {"Content-Type" => "text/plain", "Content-Length" => body.size.to_s, "X-Cascade" => "pass"}, [body]] end
NOTE:
We check via File::size? whether this file provides size info via stat (e.g. /proc files often don't), otherwise we have to figure it out by reading the whole file into memory. And while we're at it we also use this as body then.
# File lib/rack/file.rb, line 61 def serving if size = F.size?(@path) body = self else body = [F.read(@path)] size = Utils.bytesize(body.first) end [200, { "Last-Modified" => F.mtime(@path).httpdate, "Content-Type" => Mime.mime_type(F.extname(@path), 'text/plain'), "Content-Length" => size.to_s }, body] end