向现有 JSON 数组添加新元素

Question

我如何在“,”后添加逗号来添加"arn:aws:iam::xxxxxxx:role/3"下面的行。"arn:aws:iam::xxxxxxx:role/2""arn:aws:iam::xxxxxxx:role/2"

前：

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Principal": {
        "Service": "ec2.amazonaws.com"
      },
      "Action": "sts:AssumeRole"
    },
    {
      "Effect": "Allow",
      "Principal": {
        "AWS": [
          "arn:aws:iam::xxxxxxx:role/1",
          "arn:aws:iam::xxxxxxx:role/2"
        ]
      },
      "Action": "sts:AssumeRole"
    }
  ]
}

后

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Principal": {
        "Service": "ec2.amazonaws.com"
      },
      "Action": "sts:AssumeRole"
    },
    {
      "Effect": "Allow",
      "Principal": {
        "AWS": [
          "arn:aws:iam::xxxxxxx:role/1",
          "arn:aws:iam::xxxxxxx:role/2",
          "arn:aws:iam::xxxxxxx:role/3"
        ]
      },
      "Action": "sts:AssumeRole"
    }
  ]
}

Answer 1

请勿尝试使用标准文本处理工具（例如awk）sed或不使用 JSON 模块来解析 JSON 文本perl，因为它们不了解 JSON 语法。jq是一个轻量级的 JSON 处理器，可让您即时操作内容。

例如您的要求可以简单地写成

jq --arg new "arn:aws:iam::xxxxxxx:role/3" \
  '.Statement[].Principal.AWS? += [$new]' json

如果有多个元素需要附加，则将参数创建为 JSON blob

jq --argjson new \
  '["arn:aws:iam::xxxxxxx:role/3", "arn:aws:iam::xxxxxxx:role/4"]' \
  '.Statement[].Principal.AWS? += $new'

下载和使用该工具的说明位于下载 jq以及使用教程jq 手册

如果内容在文件中，而你想永久修改此文件，请使用 GNU moreutils 包中提供的就地编辑工具，sponge你可以这样做

jq --arg new "arn:aws:iam::xxxxxxx:role/3" \
  '.Statement[].Principal.AWS? += [$new]' json | sponge json

或者使用类似 POSIX 工具mktemp

temp="$(mktemp)"
jq --arg new "arn:aws:iam::xxxxxxx:role/3" \
  '.Statement[].Principal.AWS? += [$new]' json > "$temp" && mv "$temp" json