Provided by: jc_1.17.3-1_all 
NAME
jc - JSONifies the output of many CLI tools and file-types
SYNOPSIS
COMMAND | jc PARSER [OPTIONS]
or "Magic" syntax:
jc [OPTIONS] COMMAND
DESCRIPTION
jc JSONifies the output of many CLI tools and file-types for easier parsing in scripts. jc accepts piped
input from STDIN and outputs a JSON representation of the previous command's output to STDOUT.
Alternatively, the "Magic" syntax can be used by prepending jc to the command to be converted. Options
can be passed to jc immediately before the command is given. (Note: "Magic" syntax does not support shell
builtins or command aliases)
OPTIONS
Parsers:
--acpi `acpi` command parser
--airport
`airport -I` command parser
--airport-s
`airport -s` command parser
--arp `arp` command parser
--blkid
`blkid` command parser
--cksum
`cksum` and `sum` command parser
--crontab
`crontab` command and file parser
--crontab-u
`crontab` file parser with user support
--csv CSV file parser
--csv-s
CSV file streaming parser
--date `date` command parser
--df `df` command parser
--dig `dig` command parser
--dir `dir` command parser
--dmidecode
`dmidecode` command parser
--dpkg-l
`dpkg -l` command parser
--du `du` command parser
--env `env` command parser
--file `file` command parser
--finger
`finger` command parser
--free `free` command parser
--fstab
`/etc/fstab` file parser
--group
`/etc/group` file parser
--gshadow
`/etc/gshadow` file parser
--hash `hash` command parser
--hashsum
hashsum command parser (`md5sum`, `shasum`, etc.)
--hciconfig
`hciconfig` command parser
--history
`history` command parser
--hosts
`/etc/hosts` file parser
--id `id` command parser
--ifconfig
`ifconfig` command parser
--ini INI file parser
--iostat
`iostat` command parser
--iostat-s
`iostat` command streaming parser
--iptables
`iptables` command parser
--iw-scan
`iw dev [device] scan` command parser
--jobs `jobs` command parser
--kv Key/Value file parser
--last `last` and `lastb` command parser
--ls `ls` command parser
--ls-s `ls` command streaming parser
--lsblk
`lsblk` command parser
--lsmod
`lsmod` command parser
--lsof `lsof` command parser
--lsusb
`lsusb` command parser
--mount
`mount` command parser
--netstat
`netstat` command parser
--ntpq `ntpq -p` command parser
--passwd
`/etc/passwd` file parser
--ping `ping` and `ping6` command parser
--ping-s
`ping` and `ping6` command streaming parser
--pip-list
`pip list` command parser
--pip-show
`pip show` command parser
--ps `ps` command parser
--route
`route` command parser
--rpm-qi
`rpm -qi` command parser
--sfdisk
`sfdisk` command parser
--shadow
`/etc/shadow` file parser
--ss `ss` command parser
--stat `stat` command parser
--sysctl
`sysctl` command parser
--systemctl
`systemctl` command parser
--systemctl-lj
`systemctl list-jobs` command parser
--systemctl-ls
`systemctl list-sockets` command parser
--systemctl-luf
`systemctl list-unit-files` command parser
--systeminfo
`systeminfo` command parser
--time `/usr/bin/time` command parser
--timedatectl
`timedatectl status` command parser
--tracepath
`tracepath` and `tracepath6` command parser
--traceroute
`traceroute` and `traceroute6` command parser
--ufw `ufw status` command parser
--ufw-appinfo
`ufw app info [application]` command parser
--uname
`uname -a` command parser
--upower
`upower` command parser
--uptime
`uptime` command parser
--vmstat
`vmstat` command parser
--vmstat-s
`vmstat` command streaming parser
--w `w` command parser
--wc `wc` command parser
--who `who` command parser
--xml XML file parser
--yaml YAML file parser
Options:
-a about jc (JSON output)
-d debug - show traceback (use -dd for verbose traceback)
-h help (-h --parser_name for parser documentation)
-m monochrome output
-p pretty print output
-q quiet - suppress warnings (use -qq to ignore streaming parser errors)
-r raw JSON output
-u unbuffer output (useful for slow streaming data with streaming parsers)
-v version information
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 = 0, jc exit code = 0, combined exit code = 0 (no errors)
ifconfig exit code = 1, jc exit code = 0, combined exit code = 1 (error in ifconfig)
ifconfig exit code = 0, jc exit code = 100, combined exit code = 100 (error in jc)
ifconfig exit code = 1, jc exit code = 100, combined exit code = 101 (error in both ifconfig and
jc)
ENVIRONMENT
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
or
JC_COLORS=default,default,default,default
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 outputing
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.
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","response_ip":"1.1.1.1","icmp_seq":"1","ttl":"128","time_ms":"24.6","duplicate":false}
{"type":"reply","pattern":null,"timestamp":null,"bytes":"64","response_ip":"1.1.1.1","icmp_seq":"2","ttl":"128","time_ms":"26.8","duplicate":false}
etc...
Note: Unbuffered output can be slower for large data streams.
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 parser as a template and
simply place a .py file in the jcparsers subfolder.
Local plugin filenames must be valid python module names, therefore must consist entirely of
alphanumerics and start with a letter. Local plugins may override default plugins.
Note: The application data directory follows the XDG Base Directory Specification
CAVEATS
Locale: For best results set the LANG locale environment variable to C or en_US.UTF-8. For example,
either by setting directly on the command-line:
$ LANG=C date | jc --date
or by exporting to the environment before running commands:
$ export LANG=C
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.
EXAMPLES
Standard Syntax:
$ dig www.google.com | jc --dig -p
Magic Syntax:
$ jc -p dig www.google.com
For parser documentation:
$ jc -h --dig
AUTHOR
Kelly Brazil (kellyjonbrazil@gmail.com)
https://github.com/kellyjonbrazil/jc
COPYRIGHT
Copyright (c) 2019-2021 Kelly Brazil
License: MIT License
1.17.3 2021-12-02 jc(1)