Question 109764 in Json Question posted in
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Json – Update fields from string in JQ

I have a bash $string containing the values: abc,def and a file.json looking like this:

[
  {
    "loc": "51.12345, 12.12345",
    "city": "CityName1"
  },
  {
    "loc": "65.12345, 15.12345",
    "city": "CityName2"
  }
]

I’m trying to update the city field with the values from the string to get this result:

[
  {
    "loc": "51.12345, 12.12345",
    "city": "abc"
  },
  {
    "loc": "65.12345, 15.12345",
    "city": "def"
  }
]

I’m trying this code but it doesn’t work, any suggestions?

  string="abc,def"; jq --arg variable "$string" '.city = $string' file.json
Tags:

3

Answers


  1. 0

    With :

    > var json =   [
...     {
...       "loc": "51.12345, 12.12345",
...       "city": "CityName1"
...     },
...     {
...       "loc": "65.12345, 15.12345",
...       "city": "CityName2"
...     }
...   ]
> var c = 0
> ["abc", "def"].forEach(n => json[c++].city = n)
> console.log(JSON.stringify(json, null, 4))
[
    {
        "loc": "51.12345, 12.12345",
        "city": "abc"
    },
    {
        "loc": "65.12345, 15.12345",
        "city": "def"
    }
]

    From a script :

    #!/bin/bash

node<<EOF | sponge file.json
var json = $(< file.json)
var c = 0;
["abc", "def"].forEach(n => json[c++].city = n)
console.log(JSON.stringify(json, null, 4))
EOF

    output file:

    [
    {
        "loc": "51.12345, 12.12345",
        "city": "abc"
    },
    {
        "loc": "65.12345, 15.12345",
        "city": "def"
    }
]
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  2. 0

    You’re looking for something like this:

    $ string=abc,def
$ jq --arg cities "$string" '[., ($cities / ",")] | transpose | map(.[0] + {city: .[1]})' file.json
[
  {
    "loc": "51.12345, 12.12345",
    "city": "abc"
  },
  {
    "loc": "65.12345, 15.12345",
    "city": "def"
  }
]
$
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  3. 0

    Using reduce would be another way. Same lengths provided, it allows iterating over the entries along with their indices, which can then be used to access the input array.

    string="abc,def"
jq --arg var "$string" '
  reduce ($var / "," | to_entries)[] as {$key, $value} (.;
    .[$key].city = $value
  )
'

    I’m getting an error with jq version 1.4

    To make this approach compatible with jq 1.4, replace the variable destructuring with a plain variable, and access its parts later, e.g.

    string="abc,def"
jq --arg var "$string" '
  reduce ($var / "," | to_entries)[] as $item (.;
    .[$item.key].city = $item.value
  )
'

    Output:

    [
  {
    "loc": "51.12345, 12.12345",
    "city": "abc"
  },
  {
    "loc": "65.12345, 15.12345",
    "city": "def"
  }
]
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