# File lib/rake.rb, line 1317
1317:     def do_option(opt, value)
1318:       case opt
1319:       when '--dry-run'
1320:         verbose(true)
1321:         nowrite(true)
1322:         $dryrun = true
1323:         $trace = true
1324:       when '--help'
1325:         help
1326:         exit
1327:       when '--libdir'
1328:         $:.push(value)
1329:       when '--nosearch'
1330:         @nosearch = true
1331:       when '--prereqs'
1332:         $show_prereqs = true
1333:       when '--quiet'
1334:         verbose(false)
1335:       when '--rakefile'
1336:         RAKEFILES.clear
1337:         RAKEFILES << value
1338:       when '--require'
1339:         require value
1340:       when '--silent'
1341:         verbose(false)
1342:         $silent = true
1343:       when '--tasks'
1344:         $show_tasks = true
1345:       when '--trace'
1346:         $trace = true
1347:         verbose(true)
1348:       when '--usage'
1349:         usage
1350:         exit
1351:       when '--verbose'
1352:         verbose(true)
1353:       when '--version'
1354:         puts "rake, version #{RAKEVERSION}"
1355:         exit
1356:       when '--classic-namespace'
1357:         require 'rake/classic_namespace'
1358:       else
1359:         fail "Unknown option: #{opt}"
1360:       end
1361:     end