Shell – How to edit a JSON file using shell

jsonsedshellshell-scriptzsh

I am building a shell script that uses a JSON file.

{
  "property1": true,
  "list": [
    {
      "id": 1,
      "name": "APP1"
    },
    {
      "id": 2,
      "name": "APP2"
    }
  ],
  "property2": false
}

I need to use shell script to read the name from the list and remove its parent object from list. Basically I need to remove the object with name APP1 from the list using shell. Editing JSON structure is not an option.

Best Answer

Using the del function in jq:

jq 'del(.list[] | select(.name=="APP1"))'

If you wanted to pass the app name as a shell variable to jq you can use the --arg option:

jq --arg name "$name" 'del(.list[] | select(.name==$name))'

Related Solutions

Bash – Section wise Variable Accessing from Config File

You can create a shell function like this:

printSection()
{
  section="$1"
  found=false
  while read line
  do
    [[ $found == false && "$line" != "[$section]" ]] &&  continue
    [[ $found == true && "${line:0:1}" = '[' ]] && break
    found=true
    echo "$line"
  done
}

You can then use printSection like a command, and pass in the section as a parameter like:

printSection APP2

To get your parameter, you can use a much simpler sed now, like:

printSection APP2 | sed -n 's/^name=//p'

This will be operating on stdin and writing to stdout. So if your example config file were called named /etc/application.conf, and you wanted to store the name of APP2 in a variable app2name, you could write this:

app2name=$(printSection APP2 | sed -n 's/^name//p/' < /etc/applications.conf)

Or, you could build the parameter part into the function and skip sed altogether, like this:

printValue()
{
  section="$1"
  param="$2"
  found=false
  while read line
  do
    [[ $found == false && "$line" != "[$section]" ]] &&  continue
    [[ $found == true && "${line:0:1}" = '[' ]] && break
    found=true
    [[ "${line%=*}" == "$param" ]] && { echo "${line#*=}"; break; }
  done
}

Then you would assign your var like this:

app2name=$(printValue APP2 name < /etc/applications.conf)

Best Answer

Related Solutions

Bash – Section wise Variable Accessing from Config File

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