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