diff -r 1b096869b568 -r 1d3cfd4837a8 rake/helpers.rb
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/rake/helpers.rb	Wed May 07 18:22:04 2008 +0000
@@ -0,0 +1,353 @@
+#####################################################################
+###	G L O B A L   H E L P E R   F U N C T I O N S
+#####################################################################
+
+require 'pathname'
+require 'readline'
+require 'open3'
+
+# Set some ANSI escape code constants (Shamelessly stolen from Perl's
+# Term::ANSIColor by Russ Allbery <rra@stanford.edu> and Zenin <zenin@best.com>
+ANSI_ATTRIBUTES = {
+	'clear'      => 0,
+	'reset'      => 0,
+	'bold'       => 1,
+	'dark'       => 2,
+	'underline'  => 4,
+	'underscore' => 4,
+	'blink'      => 5,
+	'reverse'    => 7,
+	'concealed'  => 8,
+
+	'black'      => 30,   'on_black'   => 40, 
+	'red'        => 31,   'on_red'     => 41, 
+	'green'      => 32,   'on_green'   => 42, 
+	'yellow'     => 33,   'on_yellow'  => 43, 
+	'blue'       => 34,   'on_blue'    => 44, 
+	'magenta'    => 35,   'on_magenta' => 45, 
+	'cyan'       => 36,   'on_cyan'    => 46, 
+	'white'      => 37,   'on_white'   => 47
+}
+
+
+CLEAR_TO_EOL       = "\e[K"
+CLEAR_CURRENT_LINE = "\e[2K"
+
+
+### Output a logging message
+def log( *msg )
+	output = colorize( msg.flatten.join(' '), 'cyan' )
+	$deferr.puts( output )
+end
+
+
+### Output a logging message if tracing is on
+def trace( *msg )
+	return unless $trace
+	output = colorize( msg.flatten.join(' '), 'yellow' )
+	$deferr.puts( output )
+end
+
+
+### Run the specified command +cmd+ with system(), failing if the execution
+### fails.
+def run( *cmd )
+	cmd.flatten!
+
+	log( cmd.collect {|part| part =~ /\s/ ? part.inspect : part} ) 
+	if $dryrun
+		$deferr.puts "(dry run mode)"
+	else
+		system( *cmd )
+		unless $?.success?
+			fail "Command failed: [%s]" % [cmd.join(' ')]
+		end
+	end
+end
+
+
+### Open a pipe to a process running the given +cmd+ and call the given block with it.
+def pipeto( *cmd )
+	$DEBUG = true
+
+	cmd.flatten!
+	log( "Opening a pipe to: ", cmd.collect {|part| part =~ /\s/ ? part.inspect : part} ) 
+	if $dryrun
+		$deferr.puts "(dry run mode)"
+	else
+		open( '|-', 'w+' ) do |io|
+		
+			# Parent
+			if io
+				yield( io )
+
+			# Child
+			else
+				exec( *cmd )
+				fail "Command failed: [%s]" % [cmd.join(' ')]
+			end
+		end
+	end
+end
+
+
+### Download the file at +sourceuri+ via HTTP and write it to +targetfile+.
+def download( sourceuri, targetfile )
+	oldsync = $defout.sync
+	$defout.sync = true
+	require 'net/http'
+	require 'uri'
+
+	targetpath = Pathname.new( targetfile )
+
+	log "Downloading %s to %s" % [sourceuri, targetfile]
+	targetpath.open( File::WRONLY|File::TRUNC|File::CREAT, 0644 ) do |ofh|
+	
+		url = URI.parse( sourceuri )
+		downloaded = false
+		limit = 5
+		
+		until downloaded or limit.zero?
+			Net::HTTP.start( url.host, url.port ) do |http|
+				req = Net::HTTP::Get.new( url.path )
+
+				http.request( req ) do |res|
+					if res.is_a?( Net::HTTPSuccess )
+						log "Downloading..."
+						res.read_body do |buf|
+							ofh.print( buf )
+						end
+						downloaded = true
+						puts "done."
+		
+					elsif res.is_a?( Net::HTTPRedirection )
+						url = URI.parse( res['location'] )
+						log "...following redirection to: %s" % [ url ]
+						limit -= 1
+						sleep 0.2
+						next
+				
+					else
+						res.error!
+					end
+				end
+			end
+		end
+	end
+	
+	return targetpath
+ensure
+	$defout.sync = oldsync
+end
+
+
+### Return the fully-qualified path to the specified +program+ in the PATH.
+def which( program )
+	ENV['PATH'].split(/:/).
+		collect {|dir| Pathname.new(dir) + program }.
+		find {|path| path.exist? && path.executable? }
+end
+
+
+### Create a string that contains the ANSI codes specified and return it
+def ansi_code( *attributes )
+	attributes.flatten!
+	attributes.collect! {|at| at.to_s }
+	# $deferr.puts "Returning ansicode for TERM = %p: %p" %
+	# 	[ ENV['TERM'], attributes ]
+	return '' unless /(?:vt10[03]|xterm(?:-color)?|linux|screen)/i =~ ENV['TERM']
+	attributes = ANSI_ATTRIBUTES.values_at( *attributes ).compact.join(';')
+
+	# $deferr.puts "  attr is: %p" % [attributes]
+	if attributes.empty? 
+		return ''
+	else
+		return "\e[%sm" % attributes
+	end
+end
+
+
+### Colorize the given +string+ with the specified +attributes+ and return it, handling 
+### line-endings, color reset, etc.
+def colorize( *args )
+	string = ''
+	
+	if block_given?
+		string = yield
+	else
+		string = args.shift
+	end
+	
+	ending = string[/(\s)$/] || ''
+	string = string.rstrip
+
+	return ansi_code( args.flatten ) + string + ansi_code( 'reset' ) + ending
+end
+
+
+### Output the specified <tt>msg</tt> as an ANSI-colored error message
+### (white on red).
+def error_message( msg, details='' )
+	$deferr.puts colorize( 'bold', 'white', 'on_red' ) { msg } + details
+end
+alias :error :error_message
+
+
+### Highlight and embed a prompt control character in the given +string+ and return it.
+def make_prompt_string( string )
+	return CLEAR_CURRENT_LINE + colorize( 'bold', 'green' ) { string + ' ' }
+end
+
+
+### Output the specified <tt>prompt_string</tt> as a prompt (in green) and
+### return the user's input with leading and trailing spaces removed.  If a
+### test is provided, the prompt will repeat until the test returns true.
+### An optional failure message can also be passed in.
+def prompt( prompt_string, failure_msg="Try again." ) # :yields: response
+	prompt_string.chomp!
+	prompt_string << ":" unless /\W$/.match( prompt_string )
+	response = nil
+
+	begin
+		prompt = make_prompt_string( prompt_string )
+		response = Readline.readline( prompt ) || ''
+		response.strip!
+		if block_given? && ! yield( response ) 
+			error_message( failure_msg + "\n\n" )
+			response = nil
+		end
+	end while response.nil?
+
+	return response
+end
+
+
+### Prompt the user with the given <tt>prompt_string</tt> via #prompt,
+### substituting the given <tt>default</tt> if the user doesn't input
+### anything.  If a test is provided, the prompt will repeat until the test
+### returns true.  An optional failure message can also be passed in.
+def prompt_with_default( prompt_string, default, failure_msg="Try again." )
+	response = nil
+
+	begin
+		response = prompt( "%s [%s]" % [ prompt_string, default ] )
+		response = default if response.empty?
+
+		if block_given? && ! yield( response ) 
+			error_message( failure_msg + "\n\n" )
+			response = nil
+		end
+	end while response.nil?
+
+	return response
+end
+
+
+### Display a description of a potentially-dangerous task, and prompt
+### for confirmation. If the user answers with anything that begins
+### with 'y', yield to the block, else raise with an error.
+def ask_for_confirmation( description )
+	puts description
+
+	answer = prompt_with_default( "Continue?", 'n' ) do |input|
+		input =~ /^[yn]/i
+	end
+
+	case answer
+	when /^y/i
+		yield
+	else
+		error "Aborted."
+		fail
+	end
+end
+
+
+### Search line-by-line in the specified +file+ for the given +regexp+, returning the
+### first match, or nil if no match was found. If the +regexp+ has any capture groups,
+### those will be returned in an Array, else the whole matching line is returned.
+def find_pattern_in_file( regexp, file )
+	rval = nil
+	
+	File.open( file, 'r' ).each do |line|
+		if (( match = regexp.match(line) ))
+			rval = match.captures.empty? ? match[0] : match.captures
+			break
+		end
+	end
+
+	return rval
+end
+
+
+### Search line-by-line in the output of the specified +cmd+ for the given +regexp+,
+### returning the first match, or nil if no match was found. If the +regexp+ has any 
+### capture groups, those will be returned in an Array, else the whole matching line
+### is returned.
+def find_pattern_in_pipe( regexp, *cmd )
+	output = []
+	
+	Open3.popen3( *cmd ) do |stdin, stdout, stderr|
+		stdin.close
+
+		output << stdout.gets until stdout.eof?
+		output << stderr.gets until stderr.eof?
+	end
+	
+	result = output.find { |line| regexp.match(line) } 
+	return $1 || result
+end
+
+
+### Extract all the non Rake-target arguments from ARGV and return them.
+def get_target_args
+	args = ARGV.reject {|arg| Rake::Task.task_defined?(arg) }
+	return args
+end
+
+
+
+require 'rubygems/dependency_installer'
+require 'rubygems/source_index'
+require 'rubygems/requirement'
+require 'rubygems/doc_manager'
+
+### Install the specified +gems+ if they aren't already installed.
+def install_gems( *gems )
+	gems.flatten!
+	
+	defaults = Gem::DependencyInstaller::DEFAULT_OPTIONS.merge({
+		:generate_rdoc     => true,
+		:generate_ri       => true,
+		:install_dir       => Gem.dir,
+		:format_executable => false,
+		:test              => false,
+		:version           => Gem::Requirement.default,
+	  })
+    
+	# Check for root
+	if Process.euid != 0
+		$stderr.puts "This probably won't work, as you aren't root, but I'll try anyway"
+	end
+
+	gemindex = Gem::SourceIndex.from_installed_gems
+
+	gems.each do |gemname|
+		if (( specs = gemindex.search(gemname) )) && ! specs.empty?
+			log "Version %s of %s is already installed; skipping..." % 
+				[ specs.first.version, specs.first.name ]
+			next
+		end
+
+		log "Trying to install #{gemname.inspect}..."
+		installer = Gem::DependencyInstaller.new
+		installer.install( gemname )
+
+		installer.installed_gems.each do |spec|
+			log "Installed: %s" % [ spec.full_name ]
+		end
+
+	end
+end
+
+