From: Michael Orlitzky <michael@orlitzky.com>
Date: Thu, 29 Oct 2009 14:47:47 +0000 (-0400)
Subject: Added GetOpt option parsing.
X-Git-Url: https://gitweb.michael.orlitzky.com/?a=commitdiff_plain;h=9a5310260a276a57c084d07de2bb97d78ce2a8ff;p=dead%2Fwhatever-dl.git

Added GetOpt option parsing.
Take a '--continue' option, passed on to the downloader, which determines whether or not we attempt to continue a previous download.
Modified the downloaders to throw an IOError if the output file already exists and we're not continuing a previous download.
Print the external command used to execute Wget.
---

diff --git a/bin/whatever-dl b/bin/whatever-dl
index fbc84e9..448db85 100755
--- a/bin/whatever-dl
+++ b/bin/whatever-dl
@@ -24,6 +24,9 @@
 # a symlink which points to it.
 require 'pathname'
 
+# And getoptlong to check for our one option, --continue.
+require 'getoptlong'
+
 # This bit of magic adds the parent directory (the
 # project root) to the list of ruby load paths.
 # Thus, our require statements will work regardless of
@@ -53,19 +56,56 @@ EXIT_SUCCESS = 0
 EXIT_NO_URL = 1
 EXIT_INVALID_URL = 2
 EXIT_COULDNT_GET_VIDEO_URL = 3
-EXIT_OUTPUT_FILE_ALREADY_EXISTS = 4
+EXIT_IO_ERROR = 4
 EXIT_ERROR_READING_FROM_VIDEO_URL = 5
 EXIT_CONNECTION_REFUSED = 6
 EXIT_HTTP_ERROR = 7
 EXIT_ACCESS_DENIED = 8
 
+def usage()
+  puts <<EOF
+
+Usage: whatever-dl [options] <url>
+
+Options:
+  -c, --continue        Continue downloading a previously-attempted file.
+
+EOF
+
+end
+
 # Only actually do something if this script was called
 # directly (i.e. not from the tests).
 if (__FILE__ == $0) then
+  # Default options.
+  options = { :continue => false }
+
+  # Parse the command-line options into the options hash.
+  opts = GetoptLong.new(["--continue", "-c", GetoptLong::NO_ARGUMENT],
+                        ["--help", "-h", GetoptLong::NO_ARGUMENT])
+
+  opts.each do |opt, arg|
+    case opt
+    when '--help'
+      usage()
+      Kernel.exit(EXIT_SUCCESS)
+    when '--continue'
+      options[:continue] = true
+    end
+  end
+
+  # Warn about nonsensical options.
+  if options[:continue] and not (Configuration::DOWNLOAD_METHOD == :wget)
+    puts 'WARNING: The --continue flag does nothing unless DOWNLOAD_METHOD is :wget.'
+  end
+
+  # Note that GetoptLong steals its arguments from ARGV, so we don't need
+  # to take optional arguments into account when figuring out whether or not
+  # we were passed a URL.
   if (ARGV.length < 1) then
     # If the user didn't give us a URL, yell
     # at him or her.
-    puts 'Usage: whatever-dl <url>'
+    usage()
     Kernel.exit(EXIT_NO_URL)
   end
 
@@ -83,11 +123,6 @@ if (__FILE__ == $0) then
     puts 'Error retrieving video URL.'
     exit(EXIT_COULDNT_GET_VIDEO_URL)
   end
-    
-  if File.exists?(site.get_video_filename())
-    puts "Error: output file already exists. Please remove #{site.get_video_filename()}, and try again."
-    Kernel.exit(EXIT_OUTPUT_FILE_ALREADY_EXISTS)
-  end
 
   # The Downloader class is a factory; it should decide
   # which subclass we get.
@@ -98,7 +133,9 @@ if (__FILE__ == $0) then
   # naturally not report any of these, since it will die in
   # its own process.
   begin
-    downloader.download(video_url, site.get_video_filename())
+    downloader.download(video_url,
+                        site.get_video_filename(),
+                        continue=options[:continue])
   rescue Errno::ECONNREFUSED => e
     puts 'The connection to the server (to download the video file) was refused. Check your connection, and try again later.'
     Kernel.exit(EXIT_CONNECTION_REFUSED)
@@ -107,6 +144,9 @@ if (__FILE__ == $0) then
   rescue OpenURI::HTTPError => e
     puts "An HTTP error occurred while downloading the video file: #{e.message}."
     Kernel.exit(EXIT_HTTP_ERROR)
+  rescue IOError => e
+    puts "Input/Output Error: #{e.message}"
+    Kernel.exit(EXIT_IO_ERROR)
   end
 
   # Write an empty line at the end for aesthetic reasons.
diff --git a/src/downloader.rb b/src/downloader.rb
index eac7c18..742e792 100644
--- a/src/downloader.rb
+++ b/src/downloader.rb
@@ -30,7 +30,7 @@ class Downloader
 
   
   # Abstract
-  def download(url, outfile)
+  def download(url, outfile, continue=false)
     raise NotImplementedError
   end
   
diff --git a/src/open_uri_downloader.rb b/src/open_uri_downloader.rb
index 44ea037..06c9b3d 100644
--- a/src/open_uri_downloader.rb
+++ b/src/open_uri_downloader.rb
@@ -20,7 +20,11 @@ require 'src/uri_utilities'
 
 class OpenUriDownloader < Downloader
 
-  def download(url, outfile)
+  def download(url, outfile, continue=false)
+    if File.exists?(outfile)
+      raise IOError.new("Output file already exists. Please remove #{outfile}, and try again.")
+    end
+
     uri = URI.parse(url)
     
     uu = UriUtilities.new()
diff --git a/src/wget_downloader.rb b/src/wget_downloader.rb
index 2cbdd45..825ee12 100644
--- a/src/wget_downloader.rb
+++ b/src/wget_downloader.rb
@@ -18,9 +18,21 @@
 
 class WgetDownloader < Downloader
 
-  def download(url, outfile)
+  def download(url, outfile, continue=false)
+    if (continue == false and File.exists?(outfile))
+      raise IOError.new("Output file already exists. Please remove #{outfile}, and try again. If this is a partially-downloaded file, you can use the --continue flag to pick up where it left off.")
+    end
+
+    options = ''
+
+    if continue == true
+      options += '--continue'
+    end
+
     # This one's easy.
-    Kernel.exec("wget -O \"#{outfile}\" \"#{url}\"")
+    cmd = "wget #{options} -O \"#{outfile}\" \"#{url}\""
+    puts "\nExecuting external command: #{cmd}\n\n"
+    Kernel.exec(cmd)
   end
   
 end