split_tx.rb

require 'json'

count = 10
slice = 0
output = "8JJE8rUrYCG2c7jCozYMtn147bw5WWmoMU" 

unspent = JSON.load(File.read('unspent.json'))
txs = unspent["txs"][slice * count, count]
inputs, amount = txs.reduce([[], 0]) do |(inputs, amount), tx|
  [
    inputs + [{txid: tx["hash"], vout: tx["out_index"]}],
    amount + tx["amount"],
  ]
end
puts [
  "createrawtransaction",
  "'#{inputs.to_json}'",
  "'#{{output => amount}.to_json}'",
].join(" ")