jc JSONifies the output of many CLI tools, file-types, and common strings for easier parsing in scripts. See the Parsers section for supported commands, file-types, and strings.

dig example.com | jc --dig

[{"id":38052,"opcode":"QUERY","status":"NOERROR","flags":["qr","rd","ra"],
"query_num":1,"answer_num":1,"authority_num":0,"additional_num":1,
"opt_pseudosection":{"edns":{"version":0,"flags":[],"udp":4096}},"question":
{"name":"example.com.","class":"IN","type":"A"},"answer":[{"name":
"example.com.","class":"IN","type":"A","ttl":39049,"data":"93.184.216.34"}],
"query_time":49,"server":"2600:1700:bab0:d40::1#53(2600:1700:bab0:d40::1)",
"when":"Fri Apr 16 16:09:00 PDT 2021","rcvd":56,"when_epoch":1618614540,
"when_epoch_utc":null}]

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

$ dig example.com | jc --dig | jq -r '.[].answer[].data'
93.184.216.34

or using the alternative "magic" syntax:

$ jc dig example.com | jq -r '.[].answer[].data'
93.184.216.34

jc can also be used as a python library. In this case the returned value will be a python dictionary, a list of dictionaries, or even a lazy iterable of dictionaries instead of JSON:

>>> import subprocess
>>> import jc
>>>
>>> cmd_output = subprocess.check_output(['dig', 'example.com'], text=True)
>>> data = jc.parse('dig', cmd_output)
>>>
>>> data[0]['answer']
[{'name': 'example.com.', 'class': 'IN', 'type': 'A', 'ttl': 29658, 'data':
'93.184.216.34'}]

For jc Python package documentation, use help('jc'), help('jc.lib'), or see the online documentation.

Two representations of the data are available. The default representation uses a strict schema per parser and converts known numbers to int/float JSON values. Certain known values of None are converted to JSON null, known boolean values are converted, and, in some cases, additional semantic context fields are added.

To access the raw, pre-processed JSON, use the -r cli option or the raw=True function parameter in parse() when using jc as a python library.

Schemas for each parser can be found at the documentation link beside each Parser below.

Release notes can be found here.

Why Would Anyone Do This!?

For more information on the motivations for this project, please see my blog post on Bringing the Unix Philosophy to the 21st Century and my interview with Console.

Installation

There are several ways to get jc. You can install via pip, OS package repositories, or by downloading the correct binary for your architecture and running it anywhere on your filesystem.

Pip (macOS, linux, unix, Windows)

pip3 install jc

OS Package Repositories

OS	Command
Debian/Ubuntu linux	`apt-get install jc`
Fedora linux	`dnf install jc`
openSUSE linux	`zypper install jc`
Arch linux	`pacman -S jc`
NixOS linux	`nix-env -iA nixpkgs.jc` or `nix-env -iA nixos.jc`
Guix System linux	`guix install jc`
Gentoo Linux	`emerge dev-python/jc`
macOS	`brew install jc`
FreeBSD	`portsnap fetch update && cd /usr/ports/textproc/py-jc && make install clean`
Ansible filter plugin	`ansible-galaxy collection install community.general`
FortiSOAR connector	Install from FortiSOAR Connector Marketplace

For more OS Packages, see https://repology.org/project/jc/versions.

Binaries

For precompiled binaries, see Releases on Github.

Usage

jc accepts piped input from STDIN and outputs a JSON representation of the previous command's output to STDOUT.

COMMAND | jc [SLICE] [OPTIONS] PARSER
cat FILE | jc [SLICE] [OPTIONS] PARSER
echo STRING | jc [SLICE] [OPTIONS] PARSER

Alternatively, the "magic" syntax can be used by prepending jc to the command to be converted or in front of the absolute path for Proc files. Options can be passed to jc immediately before the command or Proc file path is given. (Note: command aliases and shell builtins are not supported)

jc [SLICE] [OPTIONS] COMMAND
jc [SLICE] [OPTIONS] /proc/<path-to-procfile>

The JSON output can be compact (default) or pretty formatted with the -p option.

Parsers

| Argument | Command or Filetype | Documentation | |-------------------|---------------------------------------------------------|----------------------------------------------------------------------------| | ` --acpi` | `acpi` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/acpi) | | ` --airport` | `airport -I` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/airport) | | ` --airport-s` | `airport -s` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/airport_s) | | ` --arp` | `arp` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/arp) | | ` --asciitable` | ASCII and Unicode table parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/asciitable) | | ` --asciitable-m` | multi-line ASCII and Unicode table parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/asciitable_m) | | ` --blkid` | `blkid` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/blkid) | | ` --cbt` | `cbt` (Google Bigtable) command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/cbt) | | ` --cef` | CEF string parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/cef) | | ` --cef-s` | CEF string streaming parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/cef_s) | | ` --chage` | `chage --list` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/chage) | | ` --cksum` | `cksum` and `sum` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/cksum) | | ` --clf` | Common and Combined Log Format file parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/clf) | | ` --clf-s` | Common and Combined Log Format file streaming parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/clf_s) | | ` --crontab` | `crontab` command and file parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/crontab) | | ` --crontab-u` | `crontab` file parser with user support | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/crontab_u) | | ` --csv` | CSV file parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/csv) | | ` --csv-s` | CSV file streaming parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/csv_s) | | ` --date` | `date` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/date) | | ` --datetime-iso` | ISO 8601 Datetime string parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/datetime_iso) | | ` --df` | `df` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/df) | | ` --dig` | `dig` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/dig) | | ` --dir` | `dir` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/dir) | | ` --dmidecode` | `dmidecode` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/dmidecode) | | ` --dpkg-l` | `dpkg -l` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/dpkg_l) | | ` --du` | `du` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/du) | | `--email-address` | Email Address string parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/email_address) | | ` --env` | `env` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/env) | | ` --file` | `file` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/file) | | ` --findmnt` | `findmnt` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/findmnt) | | ` --finger` | `finger` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/finger) | | ` --free` | `free` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/free) | | ` --fstab` | `/etc/fstab` file parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/fstab) | | ` --git-log` | `git log` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/git_log) | | ` --git-log-s` | `git log` command streaming parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/git_log_s) | | `--git-ls-remote` | `git ls-remote` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/git_ls_remote) | | ` --gpg` | `gpg --with-colons` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/gpg) | | ` --group` | `/etc/group` file parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/group) | | ` --gshadow` | `/etc/gshadow` file parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/gshadow) | | ` --hash` | `hash` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/hash) | | ` --hashsum` | hashsum command parser (`md5sum`, `shasum`, etc.) | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/hashsum) | | ` --hciconfig` | `hciconfig` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/hciconfig) | | ` --history` | `history` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/history) | | ` --hosts` | `/etc/hosts` file parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/hosts) | | ` --id` | `id` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/id) | | ` --ifconfig` | `ifconfig` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/ifconfig) | | ` --ini` | INI file parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/ini) | | ` --ini-dup` | INI with duplicate key file parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/ini_dup) | | ` --iostat` | `iostat` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/iostat) | | ` --iostat-s` | `iostat` command streaming parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/iostat_s) | | ` --ip-address` | IPv4 and IPv6 Address string parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/ip_address) | | ` --iptables` | `iptables` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/iptables) | | ` --iw-scan` | `iw dev [device] scan` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/iw_scan) | | ` --iwconfig` | `iwconfig` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/iwconfig) | | ` --jar-manifest` | Java MANIFEST.MF file parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/jar_manifest) | | ` --jobs` | `jobs` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/jobs) | | ` --jwt` | JWT string parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/jwt) | | ` --kv` | Key/Value file and string parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/kv) | | ` --last` | `last` and `lastb` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/last) | | ` --ls` | `ls` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/ls) | | ` --ls-s` | `ls` command streaming parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/ls_s) | | ` --lsblk` | `lsblk` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/lsblk) | | ` --lsmod` | `lsmod` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/lsmod) | | ` --lsof` | `lsof` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/lsof) | | ` --lspci` | `lspci -mmv` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/lspci) | | ` --lsusb` | `lsusb` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/lsusb) | | ` --m3u` | M3U and M3U8 file parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/m3u) | | ` --mdadm` | `mdadm` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/mdadm) | | ` --mount` | `mount` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/mount) | | ` --mpstat` | `mpstat` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/mpstat) | | ` --mpstat-s` | `mpstat` command streaming parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/mpstat_s) | | ` --netstat` | `netstat` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/netstat) | | ` --nmcli` | `nmcli` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/nmcli) | | ` --ntpq` | `ntpq -p` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/ntpq) | | ` --openvpn` | openvpn-status.log file parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/openvpn) | | ` --os-prober` | `os-prober` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/os_prober) | | ` --passwd` | `/etc/passwd` file parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/passwd) | | ` --pci-ids` | `pci.ids` file parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/pci_ids) | | ` --pgpass` | PostgreSQL password file parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/pgpass) | | ` --pidstat` | `pidstat -H` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/pidstat) | | ` --pidstat-s` | `pidstat -H` command streaming parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/pidstat_s) | | ` --ping` | `ping` and `ping6` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/ping) | | ` --ping-s` | `ping` and `ping6` command streaming parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/ping_s) | | ` --pip-list` | `pip list` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/pip_list) | | ` --pip-show` | `pip show` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/pip_show) | | ` --plist` | PLIST file parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/plist) | | ` --postconf` | `postconf -M` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/postconf) | | ` --proc` | `/proc/` file parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/proc) | | ` --ps` | `ps` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/ps) | | ` --route` | `route` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/route) | | ` --rpm-qi` | `rpm -qi` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/rpm_qi) | | ` --rsync` | `rsync` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/rsync) | | ` --rsync-s` | `rsync` command streaming parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/rsync_s) | | ` --semver` | Semantic Version string parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/semver) | | ` --sfdisk` | `sfdisk` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/sfdisk) | | ` --shadow` | `/etc/shadow` file parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/shadow) | | ` --ss` | `ss` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/ss) | | ` --ssh-conf` | `ssh` config file and `ssh -G` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/ssh_conf) | | ` --sshd-conf` | `sshd` config file and `sshd -T` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/sshd_conf) | | ` --stat` | `stat` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/stat) | | ` --stat-s` | `stat` command streaming parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/stat_s) | | ` --sysctl` | `sysctl` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/sysctl) | | ` --syslog` | Syslog RFC 5424 string parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/syslog) | | ` --syslog-s` | Syslog RFC 5424 string streaming parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/syslog_s) | | ` --syslog-bsd` | Syslog RFC 3164 string parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/syslog_bsd) | | ` --syslog-bsd-s` | Syslog RFC 3164 string streaming parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/syslog_bsd_s) | | ` --systemctl` | `systemctl` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/systemctl) | | ` --systemctl-lj` | `systemctl list-jobs` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/systemctl_lj) | | ` --systemctl-ls` | `systemctl list-sockets` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/systemctl_ls) | | `--systemctl-luf` | `systemctl list-unit-files` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/systemctl_luf) | | ` --systeminfo` | `systeminfo` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/systeminfo) | | ` --time` | `/usr/bin/time` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/time) | | ` --timedatectl` | `timedatectl status` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/timedatectl) | | ` --timestamp` | Unix Epoch Timestamp string parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/timestamp) | | ` --toml` | TOML file parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/toml) | | ` --top` | `top -b` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/top) | | ` --top-s` | `top -b` command streaming parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/top_s) | | ` --tracepath` | `tracepath` and `tracepath6` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/tracepath) | | ` --traceroute` | `traceroute` and `traceroute6` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/traceroute) | | ` --udevadm` | `udevadm info` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/udevadm) | | ` --ufw` | `ufw status` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/ufw) | | ` --ufw-appinfo` | `ufw app info [application]` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/ufw_appinfo) | | ` --uname` | `uname -a` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/uname) | | `--update-alt-gs` | `update-alternatives --get-selections` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/update_alt_gs) | | ` --update-alt-q` | `update-alternatives --query` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/update_alt_q) | | ` --upower` | `upower` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/upower) | | ` --uptime` | `uptime` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/uptime) | | ` --url` | URL string parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/url) | | ` --ver` | Version string parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/ver) | | ` --vmstat` | `vmstat` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/vmstat) | | ` --vmstat-s` | `vmstat` command streaming parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/vmstat_s) | | ` --w` | `w` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/w) | | ` --wc` | `wc` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/wc) | | ` --who` | `who` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/who) | | ` --x509-cert` | X.509 PEM and DER certificate file parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/x509_cert) | | ` --xml` | XML file parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/xml) | | ` --xrandr` | `xrandr` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/xrandr) | | ` --yaml` | YAML file parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/yaml) | | ` --zipinfo` | `zipinfo` command parser | [details](https://kellyjonbrazil.github.io/jc/docs/parsers/zipinfo) |

Options

Short	Long	Description
`-a`	`--about`	About `jc`. Prints information about `jc` and the parsers (in JSON or YAML, of course!)
`-C`	`--force-color`	Force color output even when using pipes (overrides `-m` and the `NO_COLOR` env variable)
`-d`	`--debug`	Debug mode. Prints trace messages if parsing issues are encountered (use`-dd` for verbose debugging)
`-h`	`--help`	Help. Use `jc -h --parser_name` for parser documentation. Use twice to show hidden parsers (e.g. `-hh`)
`-m`	`--monochrome`	Monochrome output
`-M`	`--meta-out`	Add metadata to output including timestamp, parser name, magic command, magic command exit code, etc.
`-p`	`--pretty`	Pretty format the JSON output
`-q`	`--quiet`	Quiet mode. Suppresses parser warning messages (use `-qq` to ignore streaming parser errors)
`-r`	`--raw`	Raw output. Provides more literal output, typically with string values and no additional semantic processing
`-u`	`--unbuffer`	Unbuffer output
`-v`	`--version`	Version information
`-y`	`--yaml-out`	YAML output
`-B`	`--bash-comp`	Generate Bash shell completion script (more info)
`-Z`	`--zsh-comp`	Generate Zsh shell completion script (more info)

Slice

Line slicing is supported using the START:STOP syntax similar to Python slicing. This allows you to skip lines at the beginning and/or end of the STDIN input you would like jc to convert.

START and STOP can be positive or negative integers or blank and allow you to specify how many lines to skip and how many lines to process. Positive and blank slices are the most memory efficient. Any negative integers in the slice will use more memory.

For example, to skip the first and last line of the following text, you could express the slice in a couple ways:

$ cat table.txt
      ### We want to skip this header ###
          col1       col2
          foo        1
          bar        2
      ### We want to skip this footer ###
$ cat table.txt | jc 1:-1 --asciitable
[{"col1":"foo","col2":"1"},{"col1":"bar","col2":"2"}]
$ cat table.txt | jc 1:4 --asciitable
[{"col1":"foo","col2":"1"},{"col1":"bar","col2":"2"}]

In this example 1:-1 and 1:4 line slices provide the same output.

When using positive integers the index location of STOP is non-inclusive. Positive slices count from the first line of the input toward the end starting at 0 as the first line. Negative slices count from the last line toward the beginning starting at -1 as the last line. This is also the way Python's slicing feature works.

Here is a breakdown of line slice options:

Slice Notation	Input Lines Processed
`START:STOP`	lines `START` through `STOP - 1`
`START:`	lines `START` through the rest of the output
`:STOP`	lines from the beginning through `STOP - 1`
`-START:STOP`	`START` lines from the end through `STOP - 1`
`START:-STOP`	lines `START` through `STOP` lines from the end
`-START:-STOP`	`START` lines from the end through `STOP` lines from the end
`-START:`	`START` lines from the end through the rest of the output
`:-STOP`	lines from the beginning through `STOP` lines from the end
`:`	all lines

Exit Codes

Any fatal errors within jc will generate an exit code of 100, otherwise the exit code will be 0.

When using the "magic" syntax (e.g. jc ifconfig eth0), jc will store the exit code of the program being parsed and add it to the jc exit code. This way it is easier to determine if an error was from the parsed program or jc.

Consider the following examples using ifconfig:

`ifconfig` exit code	`jc` exit code	Combined exit code	Interpretation
`0`	`0`	`0`	No errors
`1`	`0`	`1`	Error in `ifconfig`
`0`	`100`	`100`	Error in `jc`
`1`	`100`	`101`	Error in both `ifconfig` and `jc`

When using the "magic" syntax you can also retrieve the exit code of the called program by using the --meta-out or -M option. This will append a _jc_meta object to the output that will include the magic command information, including the exit code.

Here is an example with ping:

$ jc --meta-out -p ping -c2 192.168.1.252
{
  "destination_ip": "192.168.1.252",
  "data_bytes": 56,
  "pattern": null,
  "destination": "192.168.1.252",
  "packets_transmitted": 2,
  "packets_received": 0,
  "packet_loss_percent": 100.0,
  "duplicates": 0,
  "responses": [
    {
      "type": "timeout",
      "icmp_seq": 0,
      "duplicate": false
    }
  ],
  "_jc_meta": {
    "parser": "ping",
    "timestamp": 1661357115.27949,
    "magic_command": [
      "ping",
      "-c2",
      "192.168.1.252"
    ],
    "magic_command_exit": 2
  }
}
$ echo $?
2

Setting Custom Colors via Environment Variable

You can specify custom colors via the JC_COLORS environment variable. The JC_COLORS environment variable takes four comma separated string values in the following format:

JC_COLORS=<keyname_color>,<keyword_color>,<number_color>,<string_color>

Where colors are: black, red, green, yellow, blue, magenta, cyan, gray, brightblack, brightred, brightgreen, brightyellow, brightblue, brightmagenta, brightcyan, white, or default

For example, to set to the default colors:

JC_COLORS=blue,brightblack,magenta,green

JC_COLORS=default,default,default,default

Disable Colors via Environment Variable

You can set the NO_COLOR environment variable to any value to disable color output in jc. Note that using the -C option to force color output will override both the NO_COLOR environment variable and the -m option.

Streaming Parsers

Most parsers load all of the data from STDIN, parse it, then output the entire JSON document serially. There are some streaming parsers (e.g. ls-s and ping-s) that immediately start processing and outputting the data line-by-line as JSON Lines (aka NDJSON) while it is being received from STDIN. This can significantly reduce the amount of memory required to parse large amounts of command output (e.g. ls -lR /) and can sometimes process the data more quickly. Streaming parsers have slightly different behavior than standard parsers as outlined below.

Note: Streaming parsers cannot be used with the "magic" syntax

Ignoring Errors

You may want to ignore parsing errors when using streaming parsers since these may be used in long-lived processing pipelines and errors can break the pipe. To ignore parsing errors, use the -qq cli option or the ignore_exceptions=True argument with the parse() function. This will add a _jc_meta object to the JSON output with a success attribute. If success is true, then there were no issues parsing the line. If success is false, then a parsing issue was found and error and line fields will be added to include a short error description and the contents of the unparsable line, respectively:

Successfully parsed line with -qq option:

{
  "command_data": "data",
  "_jc_meta": {
    "success": true
  }
}

Unsuccessfully parsed line with -qq option:

{
  "_jc_meta": {
    "success": false,
    "error": "error message",
    "line": "original line data"
  }
}

Unbuffering Output

Most operating systems will buffer output that is being piped from process to process. The buffer is usually around 4KB. When viewing the output in the terminal the OS buffer is not engaged so output is immediately displayed on the screen. When piping multiple processes together, though, it may seem as if the output is hanging when the input data is very slow (e.g. ping):

$ ping 1.1.1.1 | jc --ping-s | jq
<slow output>

This is because the OS engages the 4KB buffer between jc and jq in this example. To display the data on the terminal in realtime, you can disable the buffer with the -u (unbuffer) cli option:

$ ping 1.1.1.1 | jc --ping-s -u | jq
{"type":"reply","pattern":null,"timestamp":null,"bytes":"64","respons...}
{"type":"reply","pattern":null,"timestamp":null,"bytes":"64","respons...}
...

Note: Unbuffered output can be slower for large data streams.

Using Streaming Parsers as Python Modules

Streaming parsers accept any iterable object and return an iterable object allowing lazy processing of the data. The input data should iterate on lines of string data. Examples of good input data are sys.stdin or str.splitlines().

To use the returned iterable object in your code, simply loop through it or use the next() builtin function:

import jc

result = jc.parse('ls_s', ls_command_output.splitlines())
for item in result:
    print(item["filename"])

Custom Parsers

Custom local parser plugins may be placed in a jc/jcparsers folder in your local "App data directory":

Linux/unix: $HOME/.local/share/jc/jcparsers
macOS: $HOME/Library/Application Support/jc/jcparsers
Windows: $LOCALAPPDATA\jc\jc\jcparsers

Local parser plugins are standard python module files. Use the jc/parsers/foo.py or jc/parsers/foo_s.py (streaming) parser as a template and simply place a .py file in the jcparsers subfolder.

Local plugin filenames must be valid python module names and therefore must start with a letter and consist entirely of alphanumerics and underscores. Local plugins may override default parsers.

Note: The application data directory follows the XDG Base Directory Specification

Caveats

Locale

For best results set the locale environment variables to C or en_US.UTF-8 by modifying the LC_ALL variable:

$ LC_ALL=C date | jc --date

You can also set the locale variables individually:

$ export LANG=C
$ export LC_NUMERIC=C

On some older systems UTF-8 output will be downgraded to ASCII with \\u escape sequences if the C locale does not support UTF-8 encoding.

Timezones

Some parsers have calculated epoch timestamp fields added to the output. Unless a timestamp field name has a _utc suffix it is considered naive. (i.e. based on the local timezone of the system the jc parser was run on).

If a UTC timezone can be detected in the text of the command output, the timestamp will be timezone aware and have a _utc suffix on the key name. (e.g. epoch_utc) No other timezones are supported for aware timestamps.

Use In Other Shells

jc can be used in most any shell. Some modern shells have JSON deserialization and filtering capabilities built-in which makes using jc even more convenient.

For example, the following is possible in NGS (Next Generation Shell):

myvar = ``jc dig www.google.com``[0].answer[0].data

This runs jc, parses the output JSON, and assigs the resulting data structure to a variable in a single line of code.

For more examples of how to use jc in other shells, see this wiki page.

Compatibility

Some parsers like dig, xml, csv, etc. will work on any platform. Other parsers that convert platform-specific output will generate a warning message if they are run on an unsupported platform. To see all parser information, including compatibility, run jc -ap.

You may still use a parser on an unsupported platform - for example, you may want to parse a file with linux lsof output on an macOS or Windows laptop. In that case you can suppress the warning message with the -q cli option or the quiet=True function parameter in parse():

macOS:

cat lsof.out | jc -q --lsof

or Windows:

type lsof.out | jc -q --lsof

Tested on:

Centos 7.7
Ubuntu 18.04
Ubuntu 20.04
Fedora32
macOS 10.11.6
macOS 10.14.6
NixOS
FreeBSD12
Windows 10
Windows 2016 Server
Windows 2019 Server

Contributions

Feel free to add/improve code or parsers! You can use the jc/parsers/foo.py or jc/parsers/foo_s.py (streaming) parsers as a template and submit your parser with a pull request.

Please see the Contributing Guidelines for more information.

Acknowledgments

Local parser plugin feature contributed by Dean Serenevy
CI automation and code optimizations by philippeitis
ifconfig-parser module by KnightWhoSayNi
xmltodict module by Martín Blech
ruamel.yaml module by Anthon van der Neut
trparse module by Luis Benitez
Parsing code from Conor Heine adapted for some parsers
Excellent constructive feedback from Ilya Sher

Examples

Here are some examples of jc output. For more examples, see here or the parser documentation.

arp

arp | jc -p --arp          # or:  jc -p arp

[
  {
    "address": "gateway",
    "hwtype": "ether",
    "hwaddress": "00:50:56:f7:4a:fc",
    "flags_mask": "C",
    "iface": "ens33"
  },
  {
    "address": "192.168.71.1",
    "hwtype": "ether",
    "hwaddress": "00:50:56:c0:00:08",
    "flags_mask": "C",
    "iface": "ens33"
  },
  {
    "address": "192.168.71.254",
    "hwtype": "ether",
    "hwaddress": "00:50:56:fe:7a:b4",
    "flags_mask": "C",
    "iface": "ens33"
  }
]

CSV files

cat homes.csv

"Sell", "List", "Living", "Rooms", "Beds", "Baths", "Age", "Acres", "Taxes"
142, 160, 28, 10, 5, 3,  60, 0.28,  3167
175, 180, 18,  8, 4, 1,  12, 0.43,  4033
129, 132, 13,  6, 3, 1,  41, 0.33,  1471
...

cat homes.csv | jc -p --csv

[
  {
    "Sell": "142",
    "List": "160",
    "Living": "28",
    "Rooms": "10",
    "Beds": "5",
    "Baths": "3",
    "Age": "60",
    "Acres": "0.28",
    "Taxes": "3167"
  },
  {
    "Sell": "175",
    "List": "180",
    "Living": "18",
    "Rooms": "8",
    "Beds": "4",
    "Baths": "1",
    "Age": "12",
    "Acres": "0.43",
    "Taxes": "4033"
  },
  {
    "Sell": "129",
    "List": "132",
    "Living": "13",
    "Rooms": "6",
    "Beds": "3",
    "Baths": "1",
    "Age": "41",
    "Acres": "0.33",
    "Taxes": "1471"
  }
]

/etc/hosts file

cat /etc/hosts | jc -p --hosts

[
  {
    "ip": "127.0.0.1",
    "hostname": [
      "localhost"
    ]
  },
  {
    "ip": "::1",
    "hostname": [
      "ip6-localhost",
      "ip6-loopback"
    ]
  },
  {
    "ip": "fe00::0",
    "hostname": [
      "ip6-localnet"
    ]
  }
]

ifconfig

ifconfig | jc -p --ifconfig          # or:  jc -p ifconfig

[
  {
    "name": "ens33",
    "flags": 4163,
    "state": [
      "UP",
      "BROADCAST",
      "RUNNING",
      "MULTICAST"
    ],
    "mtu": 1500,
    "ipv4_addr": "192.168.71.137",
    "ipv4_mask": "255.255.255.0",
    "ipv4_bcast": "192.168.71.255",
    "ipv6_addr": "fe80::c1cb:715d:bc3e:b8a0",
    "ipv6_mask": 64,
    "ipv6_scope": "0x20",
    "mac_addr": "00:0c:29:3b:58:0e",
    "type": "Ethernet",
    "rx_packets": 8061,
    "rx_bytes": 1514413,
    "rx_errors": 0,
    "rx_dropped": 0,
    "rx_overruns": 0,
    "rx_frame": 0,
    "tx_packets": 4502,
    "tx_bytes": 866622,
    "tx_errors": 0,
    "tx_dropped": 0,
    "tx_overruns": 0,
    "tx_carrier": 0,
    "tx_collisions": 0,
    "metric": null
  }
]

INI files

cat example.ini

foo = fiz
bar = buz

[section1]
fruit = apple
color = blue

[section2]
fruit = pear
color = green

cat example.ini | jc -p --ini

{
  "foo": "fiz",
  "bar": "buz",
  "section1": {
    "fruit": "apple",
    "color": "blue"
  },
  "section2": {
    "fruit": "pear",
    "color": "green"
  }
}

ls

$ ls -l /usr/bin | jc -p --ls          # or:  jc -p ls -l /usr/bin

[
  {
    "filename": "apropos",
    "link_to": "whatis",
    "flags": "lrwxrwxrwx.",
    "links": 1,
    "owner": "root",
    "group": "root",
    "size": 6,
    "date": "Aug 15 10:53"
  },
  {
    "filename": "ar",
    "flags": "-rwxr-xr-x.",
    "links": 1,
    "owner": "root",
    "group": "root",
    "size": 62744,
    "date": "Aug 8 16:14"
  },
  {
    "filename": "arch",
    "flags": "-rwxr-xr-x.",
    "links": 1,
    "owner": "root",
    "group": "root",
    "size": 33080,
    "date": "Aug 19 23:25"
  }
]

netstat

netstat -apee | jc -p --netstat          # or:  jc -p netstat -apee

[
  {
    "proto": "tcp",
    "recv_q": 0,
    "send_q": 0,
    "local_address": "localhost",
    "foreign_address": "0.0.0.0",
    "state": "LISTEN",
    "user": "systemd-resolve",
    "inode": 26958,
    "program_name": "systemd-resolve",
    "kind": "network",
    "pid": 887,
    "local_port": "domain",
    "foreign_port": "*",
    "transport_protocol": "tcp",
    "network_protocol": "ipv4"
  },
  {
    "proto": "tcp6",
    "recv_q": 0,
    "send_q": 0,
    "local_address": "[::]",
    "foreign_address": "[::]",
    "state": "LISTEN",
    "user": "root",
    "inode": 30510,
    "program_name": "sshd",
    "kind": "network",
    "pid": 1186,
    "local_port": "ssh",
    "foreign_port": "*",
    "transport_protocol": "tcp",
    "network_protocol": "ipv6"
  },
  {
    "proto": "udp",
    "recv_q": 0,
    "send_q": 0,
    "local_address": "localhost",
    "foreign_address": "0.0.0.0",
    "state": null,
    "user": "systemd-resolve",
    "inode": 26957,
    "program_name": "systemd-resolve",
    "kind": "network",
    "pid": 887,
    "local_port": "domain",
    "foreign_port": "*",
    "transport_protocol": "udp",
    "network_protocol": "ipv4"
  },
  {
    "proto": "raw6",
    "recv_q": 0,
    "send_q": 0,
    "local_address": "[::]",
    "foreign_address": "[::]",
    "state": "7",
    "user": "systemd-network",
    "inode": 27001,
    "program_name": "systemd-network",
    "kind": "network",
    "pid": 867,
    "local_port": "ipv6-icmp",
    "foreign_port": "*",
    "transport_protocol": null,
    "network_protocol": "ipv6"
  },
  {
    "proto": "unix",
    "refcnt": 2,
    "flags": null,
    "type": "DGRAM",
    "state": null,
    "inode": 33322,
    "program_name": "systemd",
    "path": "/run/user/1000/systemd/notify",
    "kind": "socket",
    "pid": 1607
  }
]

/etc/passwd file

cat /etc/passwd | jc -p --passwd

[
  {
    "username": "root",
    "password": "*",
    "uid": 0,
    "gid": 0,
    "comment": "System Administrator",
    "home": "/var/root",
    "shell": "/bin/sh"
  },
  {
    "username": "daemon",
    "password": "*",
    "uid": 1,
    "gid": 1,
    "comment": "System Services",
    "home": "/var/root",
    "shell": "/usr/bin/false"
  }
]

ping

ping 8.8.8.8 -c 3 | jc -p --ping          # or:  jc -p ping 8.8.8.8 -c 3

{
  "destination_ip": "8.8.8.8",
  "data_bytes": 56,
  "pattern": null,
  "destination": "8.8.8.8",
  "packets_transmitted": 3,
  "packets_received": 3,
  "packet_loss_percent": 0.0,
  "duplicates": 0,
  "time_ms": 2005.0,
  "round_trip_ms_min": 23.835,
  "round_trip_ms_avg": 30.46,
  "round_trip_ms_max": 34.838,
  "round_trip_ms_stddev": 4.766,
  "responses": [
    {
      "type": "reply",
      "timestamp": null,
      "bytes": 64,
      "response_ip": "8.8.8.8",
      "icmp_seq": 1,
      "ttl": 118,
      "time_ms": 23.8,
      "duplicate": false
    },
    {
      "type": "reply",
      "timestamp": null,
      "bytes": 64,
      "response_ip": "8.8.8.8",
      "icmp_seq": 2,
      "ttl": 118,
      "time_ms": 34.8,
      "duplicate": false
    },
    {
      "type": "reply",
      "timestamp": null,
      "bytes": 64,
      "response_ip": "8.8.8.8",
      "icmp_seq": 3,
      "ttl": 118,
      "time_ms": 32.7,
      "duplicate": false
    }
  ]
}

ps

ps axu | jc -p --ps          # or:  jc -p ps axu

[
  {
    "user": "root",
    "pid": 1,
    "cpu_percent": 0.0,
    "mem_percent": 0.1,
    "vsz": 128072,
    "rss": 6784,
    "tty": null,
    "stat": "Ss",
    "start": "Nov09",
    "time": "0:08",
    "command": "/usr/lib/systemd/systemd --switched-root --system --deseria..."
  },
  {
    "user": "root",
    "pid": 2,
    "cpu_percent": 0.0,
    "mem_percent": 0.0,
    "vsz": 0,
    "rss": 0,
    "tty": null,
    "stat": "S",
    "start": "Nov09",
    "time": "0:00",
    "command": "[kthreadd]"
  },
  {
    "user": "root",
    "pid": 4,
    "cpu_percent": 0.0,
    "mem_percent": 0.0,
    "vsz": 0,
    "rss": 0,
    "tty": null,
    "stat": "S<",
    "start": "Nov09",
    "time": "0:00",
    "command": "[kworker/0:0H]"
  }
]

traceroute

traceroute -m 2 8.8.8.8 | jc -p --traceroute
# or:  jc -p traceroute -m 2 8.8.8.8

{
  "destination_ip": "8.8.8.8",
  "destination_name": "8.8.8.8",
  "hops": [
    {
      "hop": 1,
      "probes": [
        {
          "annotation": null,
          "asn": null,
          "ip": "192.168.1.254",
          "name": "dsldevice.local.net",
          "rtt": 6.616
        },
        {
          "annotation": null,
          "asn": null,
          "ip": "192.168.1.254",
          "name": "dsldevice.local.net",
          "rtt": 6.413
        },
        {
          "annotation": null,
          "asn": null,
          "ip": "192.168.1.254",
          "name": "dsldevice.local.net",
          "rtt": 6.308
        }
      ]
    },
    {
      "hop": 2,
      "probes": [
        {
          "annotation": null,
          "asn": null,
          "ip": "76.220.24.1",
          "name": "76-220-24-1.lightspeed.sntcca.sbcglobal.net",
          "rtt": 29.367
        },
        {
          "annotation": null,
          "asn": null,
          "ip": "76.220.24.1",
          "name": "76-220-24-1.lightspeed.sntcca.sbcglobal.net",
          "rtt": 40.197
        },
        {
          "annotation": null,
          "asn": null,
          "ip": "76.220.24.1",
          "name": "76-220-24-1.lightspeed.sntcca.sbcglobal.net",
          "rtt": 29.162
        }
      ]
    }
  ]
}

uptime

uptime | jc -p --uptime          # or:  jc -p uptime

{
  "time": "11:35",
  "uptime": "3 days, 4:03",
  "users": 5,
  "load_1m": 1.88,
  "load_5m": 2.0,
  "load_15m": 1.94,
  "time_hour": 11,
  "time_minute": 35,
  "time_second": null,
  "uptime_days": 3,
  "uptime_hours": 4,
  "uptime_minutes": 3,
  "uptime_total_seconds": 273780
}

XML files

cat cd_catalog.xml

<?xml version="1.0" encoding="UTF-8"?>
<CATALOG>
  <CD>
    <TITLE>Empire Burlesque</TITLE>
    <ARTIST>Bob Dylan</ARTIST>
    <COUNTRY>USA</COUNTRY>
    <COMPANY>Columbia</COMPANY>
    <PRICE>10.90</PRICE>
    <YEAR>1985</YEAR>
  </CD>
  <CD>
    <TITLE>Hide your heart</TITLE>
    <ARTIST>Bonnie Tyler</ARTIST>
    <COUNTRY>UK</COUNTRY>
    <COMPANY>CBS Records</COMPANY>
    <PRICE>9.90</PRICE>
    <YEAR>1988</YEAR>
  </CD>
  ...

cat cd_catalog.xml | jc -p --xml

{
  "CATALOG": {
    "CD": [
      {
        "TITLE": "Empire Burlesque",
        "ARTIST": "Bob Dylan",
        "COUNTRY": "USA",
        "COMPANY": "Columbia",
        "PRICE": "10.90",
        "YEAR": "1985"
      },
      {
        "TITLE": "Hide your heart",
        "ARTIST": "Bonnie Tyler",
        "COUNTRY": "UK",
        "COMPANY": "CBS Records",
        "PRICE": "9.90",
        "YEAR": "1988"
      }
    ]
  }
}

YAML files

cat istio.yaml

apiVersion: "authentication.istio.io/v1alpha1"
kind: "Policy"
metadata:
  name: "default"
  namespace: "default"
spec:
  peers:
  - mtls: {}
---
apiVersion: "networking.istio.io/v1alpha3"
kind: "DestinationRule"
metadata:
  name: "default"
  namespace: "default"
spec:
  host: "*.default.svc.cluster.local"
  trafficPolicy:
    tls:
      mode: ISTIO_MUTUAL

cat istio.yaml | jc -p --yaml

[
  {
    "apiVersion": "authentication.istio.io/v1alpha1",
    "kind": "Policy",
    "metadata": {
      "name": "default",
      "namespace": "default"
    },
    "spec": {
      "peers": [
        {
          "mtls": {}
        }
      ]
    }
  },
  {
    "apiVersion": "networking.istio.io/v1alpha3",
    "kind": "DestinationRule",
    "metadata": {
      "name": "default",
      "namespace": "default"
    },
    "spec": {
      "host": "*.default.svc.cluster.local",
      "trafficPolicy": {
        "tls": {
          "mode": "ISTIO_MUTUAL"
        }
      }
    }
  }
]

Description

CLI tool and python library that converts the output of popular command-line tools, file-types, and common strings to JSON, YAML, or Dictionaries. This allows piping of output to tools like jq and simplifying automation scripts.

bash bash-scripting cli command-line command-line-interface command-line-tool convert json linux parsers python python-library scripting serialize shell-scripting yaml

Readme 27 MiB