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Accepted
KK Patel
Asked: 2013-03-26 22:23:47 +0800 CST

Bash script that convert any output (text) to json form

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I want to create bash script that it converts output of other scripts (Normally simple text) in a valid json form. How can I do this ?

Example:

awk '/^Mem/ {printf("%u%%", 100*$3/$2);}' <(free -m)

command give me used memory. I want to get output in valid jason form.

Desired output:

 {“Memory”:”80”}
bash

3 Answers

  1. free -k | { read 
    read TITLE TOTAL USED REST
    echo "{\"Memory\":\"$(( 100 * $USED / $TOTAL ))\"}"
}

    The output of free is piped to a compound command consisting of:
    A first "read" which skips the first output line of "free".
    A second "read" which reads the line we need, we need only the second and third value.
    An echo which prints the line in the format you want including the calculation

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  2. Best Answer

    Here's an example for memory:

    echo {\"Memory\":\"$(awk '/^Mem/ {printf("%u", 100*$3/$2);}' <(free -m))\"} > mem.json

    Putting that new file name into json:

    echo {\"file\":\"$(ls mem.json)\"} > filename.json

    Or:

    echo {\"<paramName-here>\":\"$(<value-of-param-from-command-here>)\"} > mem.json

    When it gets more complicated than this, you can continue to write line by line or more likely build strings in a variable.

    • 3

  3. I created a tool called jc that converts the output of many command line tools, inclduing free to json:

    $ jc free | jq
[
  {
    "type": "Mem",
    "total": 3993360,
    "used": 293248,
    "free": 3185992,
    "shared": 1196,
    "buff_cache": 514120,
    "available": 3465280
  },
  {
    "type": "Swap",
    "total": 2097148,
    "used": 0,
    "free": 2097148
  }
]

    https://github.com/kellyjonbrazil/jc

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