bash 在运行时替换 json 中的值

Replace value in json during run time

提问by Sandeep Sharma

I am trying to replace value on run time in json i.e.

我正在尝试在 json 中替换运行时的值

Old

老的

{
  "containerDefinitions": [{
    "name": "containername",
    "image": "myimage",
    "memory": 512,
    "cpu": 1,
    "essential": true,
    "portMappings": [{
      "hostPort": 80,
      "containerPort": 80,
      "protocol": "tcp"
    }]
  }],
  "volumes": [],
  "family": "containername"
}

New should be

新的应该是

{
  "containerDefinitions": [{
    "name": "containername",
    "image": "new image",
    "memory": 512,
    "cpu": 1,
    "essential": true,
    "portMappings": [{
      "hostPort": 80,
      "containerPort": 80,
      "protocol": "tcp"
    }]
  }],
  "volumes": [],
  "family": "containername"
}

• Old value: - "image": "myimage"
• New Value: - "image": "new image"

• 旧值：-“图像”：“我的图像”
• 新值：-“图像”：“新图像”

I want to do in bash. Is there any best way to do? Can we do through jq?

我想在 bash 中做。有什么最好的办法吗？可以通过jq吗？

回答by 7171u

You can use jq for this:

您可以为此使用 jq：

jq '.containerDefinitions[].image="new image"' old.son

回答by Sandeep Sharma

You should really use a tool or library that understands JSON. But if your input looks as above, you can use sed:

您真的应该使用理解 JSON 的工具或库。但是，如果您的输入看起来如上，则可以使用sed：

$ sed -i '/"image": "myimage"/s/"myimage"/"new image"/' input.json

回答by cb0

This is basically what user suggested, inside a minimalist script! This uses no external programs but depends on bash!

这基本上是用户建议的，在极简脚本中！这不使用外部程序，而是依赖于 bash！

Your new json will be stored in the newStrvariable.

您的新 json 将存储在newStr变量中。

#!/bin/bash

str='
{
  "containerDefinitions": [{
    "name": "containername",
    "image": "myimage",
    "memory": 512,
    "cpu": 1,
    "essential": true,
    "portMappings": [{
      "hostPort": 80,
      "containerPort": 80,
      "protocol": "tcp"
    }]
  }],
  "volumes": [],
  "family": "containername"
}'

replaceValue='"myimage"'
replaceWith='"new image"'
newStr=${str//$replaceValue/$replaceWith}
echo $newStr

Output:

输出：

{ "containerDefinitions": [{ "name": "containername", "image": "new image", "memory": 512, "cpu": 1, "essential": true, "portMappings": [{ "hostPort": 80, "containerPort": 80, "protocol": "tcp" }] }], "volumes": [], "family": "containername" }

{ "containerDefinitions": [{ "name": "containername", "image": "new image", "memory": 512, "cpu": 1, "essential": true, "portMappings": [{ "hostPort ": 80, "containerPort": 80, "protocol": "tcp" }] }], "volumes": [], "family": "containername" }

回答by Mat

Something like this should works for you:

像这样的事情应该适合你：

oldValue='"image": "myimage"'
newValue=${oldValue//myimage/newImage}
echo newValue

In oldValueshould be your json.

在oldValue应该是你的json。

回答by Peter Kahn

If python is reliably present, then you can use embedded python like so:

如果python可靠存在，那么您可以像这样使用嵌入式python：

• setup multiline string

• execute and fail on error

  #!/usr/bin/evn bash
  # python as multi line string
  
  read -r -d '' PYSCRIPT << ENDPY
  import json
  import os
  jsonfile = 'daemon.json'
  data = {}
  if os.path.exists(jsonfile):
      data = json.load(open(jsonfile))
  data["booleanVar"] = True
  data["stringVar"] = "foo"
  with open(jsonfile, 'w') as fp:
      json.dump(data, fp)
  ENDPY
  
  # execute python and fail on error
  
  echo "$PYSCRIPT" |python - || exit 1
  

• 设置多行字符串

• 执行并出错失败

  #!/usr/bin/evn bash
  # python as multi line string
  
  read -r -d '' PYSCRIPT << ENDPY
  import json
  import os
  jsonfile = 'daemon.json'
  data = {}
  if os.path.exists(jsonfile):
      data = json.load(open(jsonfile))
  data["booleanVar"] = True
  data["stringVar"] = "foo"
  with open(jsonfile, 'w') as fp:
      json.dump(data, fp)
  ENDPY
  
  # execute python and fail on error
  
  echo "$PYSCRIPT" |python - || exit 1
  

回答by pkaramol

Given that linuxdoes not by itself allow redirection to the same file, you can use the spongeutility from moreutilspackage

鉴于它linux本身不允许重定向到同一文件，您可以使用包中的sponge实用moreutils程序

- apt update && apt install -y moreutils
- jq '.json_label="json_value"' file.json | sponge file.json

This will truly allow in line replacement;

这将真正允许在线更换；