gopher file server

gopher-server.rb

@@ -0,0 +1,169 @@
+#!/usr/bin/env ruby -w
+
+require 'socket'
+require 'optparse'
+
+
+
+TEXT = {
+    ".c" => true,
+    ".h" => true,
+    ".txt" => true,
+    ".text" => true,
+    ".rb" => true
+}
+
+def do_error(client, message)
+
+    client.write("i#{message}\r\n")
+    client.write(".\r\n")
+    
+end
+
+def get_type(path)
+
+    ext = File.extname(path).downcase
+        
+    return 0 if TEXT[ext]
+    return 9
+    
+end
+
+def dd(client, name, path, type)
+
+  hostname = Thread.current[:hostname]
+  port = Thread.current[:port]
+  
+  client.write("#{type}#{name}\t#{path}\t#{hostname}\t#{port}\r\n")
+  
+end
+
+def do_directory(client, dir, root)
+
+    dir.each do |file|
+        next if file =~ /^\./
+        type = nil
+        
+        path = dir.path + '/' + file
+        st = File::Stat.new(path)
+        if st.directory?
+            dd(client, file + '/', root + file + '/', '1')      
+            next
+        end
+        if st.file?
+            type = get_type(file)
+            dd(client, file, root + file, type)      
+        end    
+    end
+    
+    client.write(".\r\n")
+end
+
+def do_request(client)
+
+    req = client.gets("\r\n").chomp()
+    
+    if req == nil || req == ""
+        do_directory(client, Dir.new('.'), '/')
+        return
+    end
+    
+    # remove leading /
+    req.sub!(%r{^/*},'')
+    
+    return do_error(client, 'Invalid request') if req =~ /\.\./
+    
+    begin
+        st = File::Stat.new(req) or return do_error(client, 'Invalid Request')
+    rescue SystemCallError
+        return do_error(client, 'Invalid Request')
+    end
+    
+    if st.directory?
+        # check for /../
+        req = '/' + req + '/'
+        req.gsub!(%r{//}, "/")
+        req.gsub!(%r{/./}, "/")
+        
+        do_error(client, "Invalid resource") if req =~ /\.\./
+        
+        do_directory(client, Dir.new('.' + req), req)
+        return
+    end
+    
+    return unless st.file?
+    
+    if get_type(req) == 0
+        # text
+        IO.foreach(req, "\n") {|x|
+            x.chomp!
+            x = "." + x if x =~ /^\./ 
+            client.write(x)
+            client.write("\r\n")
+        }
+        client.write(".\r\n")
+    else
+        # binary
+        client.binmode()
+        File.open(req, "rb") do |io|
+        
+            loop do
+                x = io.read(256) or break
+                client.write(x)
+            end
+        
+        end
+    end
+end
+
+# main
+
+
+
+hostname = "imac.local"
+port = 7070
+
+OptionParser.new { |opts|
+
+    opts.banner = "Usage: gopher-server [-p port]"
+    
+    opts.on('-p P', '--port P', Integer, 'Port') do |x|
+        port = x
+        puts "port = #{port}"
+    end
+    
+    opts.on_tail('-h', '--help', 'Help') do
+        puts opts
+        exit
+    end
+
+
+}.parse!
+
+
+server = TCPServer.new("0.0.0.0", port)
+loop do
+    Thread.start(server.accept) do |client|
+        begin
+            addr = client.getpeername() # client.remote_address()  # client.peeraddr(false)
+            addr = addr.unpack("C*")
+            peer = addr[4,4].join('.')
+            
+            Thread.current[:hostname] = hostname
+            Thread.current[:port] = port
+            
+            puts("accept from #{addr.join(' ')}")
+            
+            do_request(client)
+            client.flush()
+            sleep(1) # for marinetti
+        
+        rescue Exception => error
+            puts("Error: #{error}")
+            print error.backtrace.join("\n")
+        end
+        
+        client.close()
+    end
+end
+