Add bin and edit workflow

bin/gems/ffi-1.17.1-x86_64-linux-gnu/samples/qsort.rb

@@ -0,0 +1,20 @@
+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(', ')}"