[user@centos-vm ~]$ jruby -S irb
irb(main):001:0> require 'ffi'
=> true
irb(main):002:0>
irb(main):003:0* module Foo
irb(main):004:1>   extend FFI::Library
irb(main):005:1>   ffi_lib 'xml2', 'xslt', 'exslt'
irb(main):006:1> end
LoadError: Failed to load library 'xml2': Could not open library 'libxml2.so' : libxml2.so: cannot open shared object file: No such file or directory\nFailed to load library 'xslt': Could not open library 'libxslt.so' : libxslt.so: cannot open shared object file: No such file or directory\nFailed to load library 'exslt': Could not open library 'libexslt.so' : libexslt.so: cannot open shared object file: No such file or directory
        from /usr/local/jruby/lib/ruby/site_ruby/shared/ffi/library.rb:24:in `ffi_lib'
        from (irb):6
irb(main):007:0>
irb(main):008:0* p Foo.ffi_libraries.collect { |lib| lib.name }
[nil]
=> nil
irb(main):009:0>

# CentOS 5.4 doesn't have just "libxml2.so" for some reason.

[user@centos-vm ~]$ cd /usr/lib
[user@centos-vm lib]$ su
Password:
[root@centos-vm lib]# ln -s libxml2.so.2 libxml2.so
[root@centos-vm lib]# exit


[user@centos-vm lib]$ jruby -S irb
irb(main):001:0> require 'ffi'
=> true
irb(main):002:0>
irb(main):003:0* module Foo
irb(main):004:1>   extend FFI::Library
irb(main):005:1>   ffi_lib 'xml2', 'xslt', 'exslt'
irb(main):006:1> end
=> [#<FFI::DynamicLibrary:0x174f02c>]
irb(main):007:0>
irb(main):008:0* p Foo.ffi_libraries.collect { |lib| lib.name }
["libxml2.so"]
=> nil
irb(main):009:0>