问如何使用jq更新json文档中的单个整数？

EN

{
  "containerDefinitions": [
    {
      "cpu": 128,
      "image": "...",
      "memory": 512
      ...
    }
  ]
}

export TASK_DEFINITION_MEMORY=256
jq '.containerDefinitions[0].memory = env.TASK_DEFINITION_MEMORY' task_definition.json > tmp.$$.json && mv tmp.$$.json task_definition.json

{
  "containerDefinitions": [
    {
      "cpu": 128,
      "image": "...",
      "memory": 256
      ...
    }
  ]
}

{
  "containerDefinitions": [
    {
      "cpu": 128,
      "image": "...",
      "memory": "256"
      ...
    }
  ]
}