extconf.rb

gistfile1.txt

Here's part of extconf.rb from OB after some edits to add support for --prefix. Unfortunately, this doesn't work (see discussion of mkmf2 which tries to fix some of these problems)

require 'getoptlong'
makeopts = {}
opts = GetoptLong.new(["--prefix", "-p", GetoptLong::OPTIONAL_ARGUMENT],
          ["--with-openbabel-lib", "-L", GetoptLong::OPTIONAL_ARGUMENT],
          ["--with-openbabel-include", "-I", GetoptLong::OPTIONAL_ARGUMENT]
          ).each{|o, a| makeopts[o[%r/[^-].*/]] = a}
prefix = makeopts.delete('prefix') || nil
oblib = makeopts.delete('with-openbabel-lib') || nil
obinclude = makeopts.delete('with-openbabel-include') || nil
ARGV.push "--with-openbabel-lib=#{oblib}"
ARGV.push "--with-openbabel-include=#{obinclude}"

require 'mkmf'

dir_config('openbabel')

# Find a trivial header in order to add the proper include path
# to the build flags.
here = File.dirname(__FILE__)
find_header('inchi_api.h', '/usr/include/inchi', '/usr/include', here + '/../../include')

# Prevent Ruby 1.8.x from trying to compile and link the extension
# using gcc.
if RUBY_VERSION < "1.9"
  cxx = ''
  begin
    File.open('../Makefile', 'r').each_line do |line|
      if line =~ /CXX = /
        cxx = Regexp.last_match.post_match.chomp
      end
    end
  rescue Errno::ENOENT
    puts 'Please configure Open Babel before compiling the Ruby extension'
  end
  cpp_command(cxx)
end

if have_library('openbabel')
  with_ldflags("#$LDFLAGS -dynamic -flat_namespace") do #Enables cc to handle linking better.
  create_makefile('openbabel')
end
else
  puts "Install Open Babel first. If you've already compiled and installed Open Babel, you may need to run ldconfig."
end