sazwqa

Well I have to handle multiple ruby versions for different apps and change them frequently too.

So created a nifty script to change ruby versions on the fly.

# find installed ruby
Dir.chdir("C:/")
versions = Dir.glob("ruby*")[1..-1]
versions.each{|v| v.gsub!('ruby','')}
current_version = `ruby -v`
current_version_suffix = current_version.split[1].gsub('.','')
# handle mingw
if current_version =~ /mingw/
  current_version_suffix = 'win'
end

# generate menu
puts("current version: " + `ruby -v`)
puts("Installed ruby versions:")
versions.each_with_index { |v, i| p("#{i+1}. #{v}") }
print("Select number to change version, or enter to exit: ")
choice = gets.chop!
exit if choice.empty?

# rename
File.rename('c:\ruby', "ruby"+current_version_suffix)
File.rename("ruby"+versions[choice.to_i-1], 'c:\ruby')
puts("\n") if current_version_suffix =~ /19/ # for ruby 1.9
puts("changed version: " + `ruby -v`)

The above script is also available on pastie, http://pastie.org/334773

You can call it by creating shortcut for windows, like:

@ruby e:\shortcuts\change.rb

Update: Updated the script to take patchlevel in consideration:

# find installed ruby versions
Dir.chdir("c:/")
ruby_versions = Dir.glob("ruby*")[1..-1].each{|v| v.gsub!('ruby','')}
current_version_string = `ruby -v`
current_version_number = current_version_string.split[1].gsub('.','')
current_version_patchlevel = current_version_string.scan(/patchlevel\s?(\d+)/)
current_version = "#{current_version_number}p#{$1}"

# generate menu
puts("current version: #{current_version_string}")
puts("Installed ruby versions:")
ruby_versions.each_with_index { |v, i| puts("#{i+1}. #{v}") }
print("Select number to change version, or enter to exit: ")
choice = gets.chop!
exit if choice.empty?

# rename
File.rename('c:\ruby', "ruby"+current_version)
File.rename("ruby"+ruby_versions[choice.to_i-1], 'c:\ruby')
puts("changed version: #{`ruby -v`}")