JC

JSON CLI output utility

jc is used to JSONify the output of many standard linux cli tools for easier parsing in scripts. Parsers for ls, ifconfig, and netstat are currently included and more can be added via modules.

This allows further command line processing of output with tools like jq simply by piping commands:

$ ls -l /usr/bin | jc --ls | jq .[] | jq 'select(.bytes > 50000000)'
{
  "filename": "emacs",
  "flags": "-r-xr-xr-x",
  "links": 1,
  "owner": "root",
  "group": "wheel",
  "bytes": 117164432,
  "date": "May 3 22:26"
}

Installation

$ pip3 install jc

Usage

jc accepts piped input from STDIN and outputs a JSON representation of the previous command's output to STDOUT. The JSON output can be compact or pretty formatted.

The first argument is required and identifies the command that is piping output to jc input. For example:

• --ls enables the ls parser
• --ifconfig enables the ifconfig parser
• --netstat enables the netstat parser
• --ps enables the ps parser
• --route enables the route parser

The second -p argument is optional and specifies whether to pretty format the JSON output.

Examples

ls

$ ls -l /bin | jc --ls -p
[
  {
    "filename": "bash",
    "flags": "-r-xr-xr-x",
    "links": 1,
    "owner": "root",
    "group": "wheel",
    "bytes": 618416,
    "date": "May 3 22:26"
  },
  {
    "filename": "cat",
    "flags": "-rwxr-xr-x",
    "links": 1,
    "owner": "root",
    "group": "wheel",
    "bytes": 23648,
    "date": "May 3 22:26"
  },
  {
    "filename": "chmod",
    "flags": "-rwxr-xr-x",
    "links": 1,
    "owner": "root",
    "group": "wheel",
    "bytes": 30016,
    "date": "May 3 22:26"
  },
  ...
]

ifconfig

$ ifconfig | jc --ifconfig -p
[
  {
    "name": "docker0",
    "flags": "4099",
    "state": "UP,BROADCAST,MULTICAST",
    "mtu": "1500",
    "ipv4_addr": "172.17.0.1",
    "ipv4_mask": "255.255.0.0",
    "ipv4_bcast": "0.0.0.0",
    "mac_addr": "02:42:53:18:31:cc",
    "type": "Ethernet",
    "rx_packets": "0",
    "rx_errors": "0",
    "rx_dropped": "0",
    "rx_overruns": "0",
    "rx_frame": "0",
    "tx_packets": "0",
    "tx_errors": "0",
    "tx_dropped": "0",
    "tx_overruns": "0",
    "tx_carrier": "0",
    "tx_collisions": "0",
    "ipv6_addr": null,
    "ipv6_mask": null,
    "ipv6_scope": null,
    "metric": null
  },
  {
    "name": "ens33",
    "flags": "4163",
    "state": "UP,BROADCAST,RUNNING,MULTICAST",
    "mtu": "1500",
    "ipv4_addr": "192.168.71.135",
    "ipv4_mask": "255.255.255.0",
    "ipv4_bcast": "192.168.71.255",
    "ipv6_addr": "fe80::c1cb:715d:bc3e:b8a0",
    "ipv6_mask": "64",
    "ipv6_scope": "link",
    "mac_addr": "00:0c:29:3b:58:0e",
    "type": "Ethernet",
    "rx_packets": "26348",
    "rx_errors": "0",
    "rx_dropped": "0",
    "rx_overruns": "0",
    "rx_frame": "0",
    "tx_packets": "5308",
    "tx_errors": "0",
    "tx_dropped": "0",
    "tx_overruns": "0",
    "tx_carrier": "0",
    "tx_collisions": "0",
    "metric": null
  },
  {
    "name": "lo",
    "flags": "73",
    "state": "UP,LOOPBACK,RUNNING",
    "mtu": "65536",
    "ipv4_addr": "127.0.0.1",
    "ipv4_mask": "255.0.0.0",
    "ipv4_bcast": null,
    "ipv6_addr": "::1",
    "ipv6_mask": "128",
    "ipv6_scope": "host",
    "mac_addr": null,
    "type": "Local Loopback",
    "rx_packets": "64",
    "rx_errors": "0",
    "rx_dropped": "0",
    "rx_overruns": "0",
    "rx_frame": "0",
    "tx_packets": "64",
    "tx_errors": "0",
    "tx_dropped": "0",
    "tx_overruns": "0",
    "tx_carrier": "0",
    "tx_collisions": "0",
    "metric": null
  }
]

netstat

$ netstat -p | jc --netstat -p
{
  "client": {
    "tcp": {
      "ipv4": [
        {
          "local_address": "localhost.localdo",
          "local_port": "34480",
          "foreign_address": "lb-192-30-255-113",
          "foreign_port": "https",
          "state": "ESTABLISHED",
          "pid": 53550,
          "program_name": "git-remote-ht",
          "receive_q": 0,
          "send_q": 0
        },
        {
          "local_address": "localhost.localdo",
          "local_port": "34478",
          "foreign_address": "lb-192-30-255-113",
          "foreign_port": "https",
          "state": "ESTABLISHED",
          "pid": 53550,
          "program_name": "git-remote-ht",
          "receive_q": 0,
          "send_q": 0
        }
      ]
    }
  }
}

$ netstat -lp | jc --netstat -p
{
  "server": {
    "tcp": {
      "ipv4": [
        {
          "local_address": "localhost",
          "local_port": "smtp",
          "foreign_address": "0.0.0.0",
          "foreign_port": "*",
          "state": "LISTEN",
          "pid": 1594,
          "program_name": "master",
          "receive_q": 0,
          "send_q": 0
        },
        {
          "local_address": "0.0.0.0",
          "local_port": "ssh",
          "foreign_address": "0.0.0.0",
          "foreign_port": "*",
          "state": "LISTEN",
          "pid": 21918,
          "program_name": "sshd",
          "receive_q": 0,
          "send_q": 0
        }
      ],
      "ipv6": [
        {
          "local_address": "localhost",
          "local_port": "smtp",
          "foreign_address": "[::]",
          "foreign_port": "*",
          "state": "LISTEN",
          "pid": 1594,
          "program_name": "master",
          "receive_q": 0,
          "send_q": 0
        },
        {
          "local_address": "[::]",
          "local_port": "ssh",
          "foreign_address": "[::]",
          "foreign_port": "*",
          "state": "LISTEN",
          "pid": 21918,
          "program_name": "sshd",
          "receive_q": 0,
          "send_q": 0
        }
      ]
    },
    "udp": {
      "ipv4": [
        {
          "local_address": "0.0.0.0",
          "local_port": "bootpc",
          "foreign_address": "0.0.0.0",
          "foreign_port": "*",
          "pid": 13903,
          "program_name": "dhclient",
          "receive_q": 0,
          "send_q": 0
        },
        {
          "local_address": "localhost",
          "local_port": "323",
          "foreign_address": "0.0.0.0",
          "foreign_port": "*",
          "pid": 30926,
          "program_name": "chronyd",
          "receive_q": 0,
          "send_q": 0
        }
      ],
      "ipv6": [
        {
          "local_address": "localhost",
          "local_port": "323",
          "foreign_address": "[::]",
          "foreign_port": "*",
          "pid": 30926,
          "program_name": "chronyd",
          "receive_q": 0,
          "send_q": 0
        }
      ]
    }
  }
}

ps

$ ps -ef | jc --ps -p
[
  {
    "UID": "root",
    "PID": "1",
    "PPID": "0",
    "C": "0",
    "STIME": "13:58",
    "TTY": "?",
    "TIME": "00:00:05",
    "CMD": "/lib/systemd/systemd --system --deserialize 35"
  },
  {
    "UID": "root",
    "PID": "2",
    "PPID": "0",
    "C": "0",
    "STIME": "13:58",
    "TTY": "?",
    "TIME": "00:00:00",
    "CMD": "[kthreadd]"
  },
  {
    "UID": "root",
    "PID": "4",
    "PPID": "2",
    "C": "0",
    "STIME": "13:58",
    "TTY": "?",
    "TIME": "00:00:00",
    "CMD": "[kworker/0:0H]"
  },
  {
    "UID": "root",
    "PID": "6",
    "PPID": "2",
    "C": "0",
    "STIME": "13:58",
    "TTY": "?",
    "TIME": "00:00:00",
    "CMD": "[mm_percpu_wq]"
  },
  ...
]

route

$ route -n | jc --route -p
[
  {
    "Destination": "0.0.0.0",
    "Gateway": "192.168.71.2",
    "Genmask": "0.0.0.0",
    "Flags": "UG",
    "Metric": "100",
    "Ref": "0",
    "Use": "0",
    "Iface": "ens33"
  },
  {
    "Destination": "172.17.0.0",
    "Gateway": "0.0.0.0",
    "Genmask": "255.255.0.0",
    "Flags": "U",
    "Metric": "0",
    "Ref": "0",
    "Use": "0",
    "Iface": "docker0"
  },
  {
    "Destination": "192.168.71.0",
    "Gateway": "0.0.0.0",
    "Genmask": "255.255.255.0",
    "Flags": "U",
    "Metric": "0",
    "Ref": "0",
    "Use": "0",
    "Iface": "ens33"
  },
  {
    "Destination": "192.168.71.2",
    "Gateway": "0.0.0.0",
    "Genmask": "255.255.255.255",
    "Flags": "UH",
    "Metric": "100",
    "Ref": "0",
    "Use": "0",
    "Iface": "ens33"
  }
]

Contributions

Feel free to add/improve code or parsers!

Acknowledgments

• ifconfig-parser module from https://github.com/KnightWhoSayNi/ifconfig-parser
• Parsing code from Conor Heine at https://gist.github.com/cahna/43a1a3ff4d075bcd71f9d7120037a501