# File lib/rake.rb, line 1840
1840:     def do_option(opt, value)
1841:       case opt
1842:       when '--dry-run'
1843:         verbose(true)
1844:         nowrite(true)
1845:         options.dryrun = true
1846:         options.trace = true
1847:       when '--help'
1848:         help
1849:         exit
1850:       when '--libdir'
1851:         $:.push(value)
1852:       when '--nosearch'
1853:         options.nosearch = true
1854:       when '--prereqs'
1855:         options.show_prereqs = true
1856:       when '--quiet'
1857:         verbose(false)
1858:       when '--rakefile'
1859:         @rakefiles.clear
1860:         @rakefiles << value
1861:       when '--rakelibdir'
1862:         options.rakelib = value.split(':')
1863:       when '--require'
1864:         begin
1865:           require value
1866:         rescue LoadError => ex
1867:           begin
1868:             rake_require value
1869:           rescue LoadError => ex2
1870:             raise ex
1871:           end
1872:         end
1873:       when '--silent'
1874:         verbose(false)
1875:         options.silent = true
1876:       when '--tasks'
1877:         options.show_tasks = true
1878:         options.show_task_pattern = Regexp.new(value || '.')
1879:       when '--trace'
1880:         options.trace = true
1881:         verbose(true)
1882:       when '--usage'
1883:         usage
1884:         exit
1885:       when '--verbose'
1886:         verbose(true)
1887:       when '--version'
1888:         puts "rake, version #{RAKEVERSION}"
1889:         exit
1890:       when '--classic-namespace'
1891:         require 'rake/classic_namespace'
1892:         options.classic_namespace = true
1893:       end
1894:     end