JezK
Edit File: qsort.rb
require 'ffi' module LibC extend FFI::Library ffi_lib FFI::Library::LIBC callback :qsort_cmp, [ :pointer, :pointer ], :int attach_function :qsort, [ :pointer, :ulong, :ulong, :qsort_cmp ], :int end p = FFI::MemoryPointer.new(:int, 2) p.put_array_of_int32(0, [ 2, 1 ]) puts "ptr=#{p.inspect}" puts "Before qsort #{p.get_array_of_int32(0, 2).join(', ')}" LibC.qsort(p, 2, 4) do |p1, p2| i1 = p1.get_int32(0) i2 = p2.get_int32(0) puts "In block: comparing #{i1} and #{i2}" i1 < i2 ? -1 : i1 > i2 ? 1 : 0 end puts "After qsort #{p.get_array_of_int32(0, 2).join(', ')}"