johnjohndoe · December 16, 2012 17:46 · Dec 16, 2012 · Mar 26, 2012 · Mar 26, 2012
diff --git a/download.rb b/download.rb
@@ -174,7 +174,7 @@ def self.ftp_download(parsed_uri, full_path)
 if __FILE__ == $0
   usage = <<-EOU
 
-usage: ruby download.rb URL FILE
+usage: ruby #{File.basename($0)} URL FILE
 
   URL   http/https/ftp location of the file to download
   FILE  full local path at which to save downloaded file

diff --git a/download.rb b/download.rb
@@ -4,7 +4,7 @@
 #
 # Author: Jon Maken
 # License: 3-clause BSD
-# Revision: 2012-03-25 21:09:01 -0600
+# Revision: 2012-03-25 21:18:59 -0600
 
 require 'net/http'
 require 'net/https' if RUBY_VERSION < '1.9'
@@ -77,7 +77,6 @@ def self.http_download(url, full_path, count)
         end
       end
 
-      message "Downloading #{filename} "
       http.request_get(uri.path) do |response|
         case response
         when Net::HTTPNotFound

diff --git a/download.rb b/download.rb
@@ -0,0 +1,192 @@
+#!/usr/bin/env ruby
+# An HTTP/HTTPS/FTP file downloader library/CLI based upon MiniPortile's
+# HTTP implementation.
+#
+# Author: Jon Maken
+# License: 3-clause BSD
+# Revision: 2012-03-25 21:09:01 -0600
+
+require 'net/http'
+require 'net/https' if RUBY_VERSION < '1.9'
+require 'net/ftp'
+require 'fileutils'
+require 'tempfile'
+
+class Downloader
+
+  @logger = STDOUT.binmode
+  @max_ca_verify_depth = 5
+
+  def self.download_file(url, full_path, count = 3)
+    return if File.exist?(full_path)
+
+    uri = URI.parse(url)
+    case uri.scheme.downcase
+    when /ftp/
+      ftp_download(uri, full_path)
+    when /http|https/
+      http_download(url, full_path, count)
+    end
+  end
+
+
+private
+  def self.message(text)
+    @logger.print text
+    @logger.flush
+  end
+
+  def self.output(text = '')
+    @logger.puts text
+    @logger.flush
+  end
+
+  def self.http_download(url, full_path, count)
+    filename = File.basename(full_path)
+
+    begin
+      uri = URI.parse(url)
+
+      if ENV['HTTP_PROXY']
+        protocol, userinfo, proxy_host, proxy_port  = URI::split(ENV['HTTP_PROXY'])
+        proxy_user, proxy_pass = userinfo.split(/:/) if userinfo
+        http = Net::HTTP.new(uri.host, uri.port, proxy_host, proxy_port, proxy_user, proxy_pass)
+      else
+        http = Net::HTTP.new(uri.host, uri.port)
+      end
+
+      if uri.scheme.downcase == 'https'
+        http.use_ssl = true
+        if ENV['CA_CERT_FILE']
+          cert_file = ENV['CA_CERT_FILE'].dup
+          cert_file.gsub!(File::ALT_SEPARATOR, File::SEPARATOR) if File::ALT_SEPARATOR
+        end
+        if cert_file && File.exist?(cert_file)
+          http.ca_file = cert_file
+          http.verify_mode = OpenSSL::SSL::VERIFY_PEER
+          http.verify_depth = @max_ca_verify_depth
+        else
+          raise <<-EOT
+To download using HTTPS you must first set the CA_CERT_FILE
+environment variable to the path of a valid CA certificate file.
+A file of bundled public CA certs may be downloaded from:
+
+   http://curl.haxx.se/ca/cacert.pem
+
+          EOT
+        end
+      end
+
+      message "Downloading #{filename} "
+      http.request_get(uri.path) do |response|
+        case response
+        when Net::HTTPNotFound
+          output "404 - Not Found"
+          return false
+
+        when Net::HTTPClientError
+          output "Error: Client Error: #{response.inspect}"
+          return false
+
+        when Net::HTTPRedirection
+          raise "Too many redirections for the original URL, halting." if count <= 0
+          url = response["location"]
+          return download_file(url, full_path, count - 1)
+
+        when Net::HTTPOK
+          temp_file = Tempfile.new("download-#{filename}")
+          temp_file.binmode
+
+          size = 0
+          progress = 0
+          total = response.header["Content-Length"].to_i
+
+          response.read_body do |chunk|
+            temp_file << chunk
+            size += chunk.size
+            new_progress = (size * 100) / total
+            unless new_progress == progress
+              message "\rDownloading %s (%3d%%) " % [filename, new_progress]
+            end
+            progress = new_progress
+          end
+
+          output
+
+          temp_file.close
+          File.unlink full_path if File.exists?(full_path)
+          FileUtils.mkdir_p File.dirname(full_path)
+          FileUtils.mv temp_file.path, full_path, :force => true
+        end
+      end
+
+    rescue Exception => e
+      File.unlink full_path if File.exists?(full_path)
+      output "ERROR: #{e.message}"
+      raise "Failed to download file"
+    end
+  end
+
+  def self.ftp_download(parsed_uri, full_path)
+    filename = File.basename(parsed_uri.path)
+
+    begin
+      temp_file = Tempfile.new("download-#{filename}")
+      temp_file.binmode
+
+      size = 0
+      progress = 0
+
+      # TODO add user/pw support
+      Net::FTP.open(parsed_uri.host) do |ftp|
+        ftp.passive = true
+        ftp.login
+        ftp.chdir(File.dirname(parsed_uri.path))
+        total = ftp.size(filename)
+
+        ftp.getbinaryfile(filename, nil, 8192) do |chunk|
+          temp_file << chunk
+          size += chunk.size
+          new_progress = (size * 100) / total
+          unless new_progress == progress
+            message "\rDownloading %s (%3d%%) " % [filename, new_progress]
+          end
+          progress = new_progress
+        end
+      end
+
+      output
+
+      temp_file.close
+      File.unlink full_path if File.exists?(full_path)
+      FileUtils.mkdir_p File.dirname(full_path)
+      FileUtils.mv temp_file.path, full_path, :force => true
+
+    rescue Exception => e
+      File.unlink full_path if File.exists?(full_path)
+      output "ERROR: #{e.message}"
+      raise "Failed to download file"
+    end
+  end
+
+end  # Downloader
+
+
+if __FILE__ == $0
+  usage = <<-EOU
+
+usage: ruby download.rb URL FILE
+
+  URL   http/https/ftp location of the file to download
+  FILE  full local path at which to save downloaded file
+
+influential environment variables:
+
+  HTTP_PROXY    url to http proxy
+  CA_CERT_FILE  full path to CA certificate file
+  EOU
+
+  abort usage if ARGV.length != 2
+
+  Downloader.download_file(ARGV[0], ARGV[1])
+end