Create a autoinstaller file as ruby script

autoinstaller.rb

#!/usr/bin/ruby
#################################################################################
#  autopatch.rb : Create a autoinstallable script
#
# use 'tar czf' and base64 for serialize a directory in ascii data, embedded it in a ruby script.
# Executing this script will untar the data in current directory
#
#--------------------------------------------------------------------------------
# Create autoinstaller :
#  > ruby autopatch.rb /opt/foo
#
# Use it :
#  > cd other-directory
#  > ruby ..../patch-XXXX.rb
#  > ls opt
#################################################################################
require "base64"

####################### Script code embedded....

$patchScript=<<'EEND'
#!/usr/bin/ruby
require "base64"

$DATA=<<'REALYENDOFBIGDOCUMENT123435678'
therdataREALYENDOFBIGDOCUMENT123435678

puts "data :\nsize=#{$DATA.size}\nencoding=#{$DATA.encoding}\nroot directory ==>  DIRNAME"
print "Ok (y/n) : " ; rep=gets 
exit(-1) if rep.strip !~ /[oy]/
puts "ok, install..."
name="patch#{(rand*100000).to_i}.tgz"
File.open(name,"wb") { |f| f.write(Base64.decode64($DATA)) }
%x{tar xf #{name}}
File.delete(name)
puts "Done."
EEND

##################### Code for make the scipt...

dirname=ARGV.first
if ! File.exist?(dirname)
  puts "directory '#{dirname}' existe pas !" 
  exit(-1) 
end
puts "tar #{dirname}..."
tarname="newpatch#{(rand*100000).to_i}.tgz"
%x{tar czf #{tarname} #{dirname} }
puts "File tar size= #{File.size(tarname)}"
puts "make patch file..."
namefile="patch-"+Time.now.strftime("%Y-%m-%d-%Hh%M")+".rb"
File.open(namefile,"wb") { |f| f.write($patchScript.sub("DIRNAME",dirname).sub("therdata",Base64.encode64(IO.binread(tarname)))) }
File.delete(tarname)
puts "autoinstaller file is '#{namefile}' , size=#{File.size(namefile)} !"
system("chmod 777 #{namefile}")  unless Gem.win_platform?