Provided by: jc_1.25.1-1_all 
NAME
jc - JSON Convert JSONifies the output of many CLI tools, file-types, and strings
SYNOPSIS
Standard syntax:
COMMAND | jc [SLICE] [OPTIONS] PARSER
cat FILE | jc [SLICE] [OPTIONS] PARSER
echo STRING | jc [SLICE] [OPTIONS] PARSER
Magic syntax:
jc [SLICE] [OPTIONS] COMMAND
jc [SLICE] [OPTIONS] /proc/<path-to-procfile>
DESCRIPTION
jc JSONifies the output of many CLI tools, file-types, and common strings 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
--asciitable
ASCII and Unicode table parser
--asciitable-m
multi-line ASCII and Unicode table parser
--blkid
`blkid` command parser
--bluetoothctl
`bluetoothctl` command parser
--cbt `cbt` (Google Bigtable) command parser
--cef CEF string parser
--cef-s
CEF string streaming parser
--certbot
`certbot` command parser
--chage
`chage --list` command parser
--cksum
`cksum` and `sum` command parser
--clf Common and Combined Log Format file parser
--clf-s
Common and Combined Log Format file streaming 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
--curl-head
`curl --head` command parser
--date `date` command parser
--datetime-iso
ISO 8601 Datetime string parser
--debconf-show
`debconf-show` 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
--efibootmgr
`efibootmgr` command parser
--email-address
Email Address string parser
--env `env` command parser
--file `file` command parser
--find `find` command parser
--findmnt
`findmnt` command parser
--finger
`finger` command parser
--free `free` command parser
--fstab
`/etc/fstab` file parser
--git-log
`git log` command parser
--git-log-s
`git log` command streaming parser
--git-ls-remote
`git ls-remote` command parser
--gpg `gpg --with-colons` command 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
--host `host` command parser
--hosts
`/etc/hosts` file parser
--http-headers
HTTP headers parser
--id `id` command parser
--ifconfig
`ifconfig` command parser
--ini INI file parser
--ini-dup
INI with duplicate key file parser
--iostat
`iostat` command parser
--iostat-s
`iostat` command streaming parser
--ip-address
IPv4 and IPv6 Address string parser
--iptables
`iptables` command parser
--ip-route
`ip route` command parser
--iw-scan
`iw dev [device] scan` command parser
--iwconfig
`iwconfig` command parser
--jar-manifest
Java MANIFEST.MF file parser
--jobs `jobs` command parser
--jwt JWT string parser
--kv Key/Value file and string parser
--kv-dup
Key/Value with duplicate key file and string parser
--last `last` and `lastb` command parser
--ls `ls` command parser
--ls-s `ls` command streaming parser
--lsattr
`lsattr` command parser
--lsb-release
`lsb_release` command parser
--lsblk
`lsblk` command parser
--lsmod
`lsmod` command parser
--lsof `lsof` command parser
--lspci
`lspci -mmv` command parser
--lsusb
`lsusb` command parser
--m3u M3U and M3U8 file parser
--mdadm
`mdadm` command parser
--mount
`mount` command parser
--mpstat
`mpstat` command parser
--mpstat-s
`mpstat` command streaming parser
--netstat
`netstat` command parser
--nmcli
`nmcli` command parser
--nsd-control
`nsd-control` command parser
--ntpq `ntpq -p` command parser
--openvpn
openvpn-status.log file parser
--os-prober
`os-prober` command parser
--os-release
`/etc/os-release` file parser
--passwd
`/etc/passwd` file parser
--path POSIX path string parser
--path-list
POSIX path list string parser
--pci-ids
`pci.ids` file parser
--pgpass
PostgreSQL password file parser
--pidstat
`pidstat -H` command parser
--pidstat-s
`pidstat -H` command streaming 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
--pkg-index-apk
Alpine Linux Package Index file parser
--pkg-index-deb
Debian Package Index file parser
--plist
PLIST file parser
--postconf
`postconf -M` command parser
--proc `/proc/` file parser
--proc-buddyinfo
`/proc/buddyinfo` file parser
--proc-cmdline
`/proc/cmdline` file parser
--proc-consoles
`/proc/consoles` file parser
--proc-cpuinfo
`/proc/cpuinfo` file parser
--proc-crypto
`/proc/crypto` file parser
--proc-devices
`/proc/devices` file parser
--proc-diskstats
`/proc/diskstats` file parser
--proc-filesystems
`/proc/filesystems` file parser
--proc-interrupts
`/proc/interrupts` file parser
--proc-iomem
`/proc/iomem` file parser
--proc-ioports
`/proc/ioports` file parser
--proc-loadavg
`/proc/loadavg` file parser
--proc-locks
`/proc/locks` file parser
--proc-meminfo
`/proc/meminfo` file parser
--proc-modules
`/proc/modules` file parser
--proc-mtrr
`/proc/mtrr` file parser
--proc-pagetypeinfo
`/proc/pagetypeinfo` file parser
--proc-partitions
`/proc/partitions` file parser
--proc-slabinfo
`/proc/slabinfo` file parser
--proc-softirqs
`/proc/softirqs` file parser
--proc-stat
`/proc/stat` file parser
--proc-swaps
`/proc/swaps` file parser
--proc-uptime
`/proc/uptime` file parser
--proc-version
`/proc/version` file parser
--proc-vmallocinfo
`/proc/vmallocinfo` file parser
--proc-vmstat
`/proc/vmstat` file parser
--proc-zoneinfo
`/proc/zoneinfo` file parser
--proc-driver-rtc
`/proc/driver/rtc` file parser
--proc-net-arp
`/proc/net/arp` file parser
--proc-net-dev
`/proc/net/dev` file parser
--proc-net-dev-mcast
`/proc/net/dev_mcast` file parser
--proc-net-if-inet6
`/proc/net/if_inet6` file parser
--proc-net-igmp
`/proc/net/igmp` file parser
--proc-net-igmp6
`/proc/net/igmp6` file parser
--proc-net-ipv6-route
`/proc/net/ipv6_route` file parser
--proc-net-netlink
`/proc/net/netlink` file parser
--proc-net-netstat
`/proc/net/netstat` file parser
--proc-net-packet
`/proc/net/packet` file parser
--proc-net-protocols
`/proc/net/protocols` file parser
--proc-net-route
`/proc/net/route` file parser
--proc-net-tcp
`/proc/net/tcp` and `/proc/net/tcp6` file parser
--proc-net-unix
`/proc/net/unix` file parser
--proc-pid-fdinfo
`/proc/<pid>/fdinfo/<fd>` file parser
--proc-pid-io
`/proc/<pid>/io` file parser
--proc-pid-maps
`/proc/<pid>/maps` file parser
--proc-pid-mountinfo
`/proc/<pid>/mountinfo` file parser
--proc-pid-numa-maps
`/proc/<pid>/numa_maps` file parser
--proc-pid-smaps
`/proc/<pid>/smaps` file parser
--proc-pid-stat
`/proc/<pid>/stat` file parser
--proc-pid-statm
`/proc/<pid>/statm` file parser
--proc-pid-status
`/proc/<pid>/status` file parser
--ps `ps` command parser
--resolve-conf
`/etc/resolve.conf` file parser
--route
`route` command parser
--rpm-qi
`rpm -qi` command parser
--rsync
`rsync` command parser
--rsync-s
`rsync` command streaming parser
--semver
Semantic Version string parser
--sfdisk
`sfdisk` command parser
--shadow
`/etc/shadow` file parser
--srt SRT file parser
--ss `ss` command parser
--ssh-conf
`ssh` config file and `ssh -G` command parser
--sshd-conf
`sshd` config file and `sshd -T` command parser
--stat `stat` command parser
--stat-s
`stat` command streaming parser
--swapon
`swapon` command parser
--sysctl
`sysctl` command parser
--syslog
Syslog RFC 5424 string parser
--syslog-s
Syslog RFC 5424 string streaming parser
--syslog-bsd
Syslog RFC 3164 string parser
--syslog-bsd-s
Syslog RFC 3164 string streaming 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
--timestamp
Unix Epoch Timestamp string parser
--toml TOML file parser
--top `top -b` command parser
--top-s
`top -b` command streaming parser
--tracepath
`tracepath` and `tracepath6` command parser
--traceroute
`traceroute` and `traceroute6` command parser
--tune2fs
`tune2fs -l` command parser
--udevadm
`udevadm info` command parser
--ufw `ufw status` command parser
--ufw-appinfo
`ufw app info [application]` command parser
--uname
`uname -a` command parser
--update-alt-gs
`update-alternatives --get-selections` command parser
--update-alt-q
`update-alternatives --query` command parser
--upower
`upower` command parser
--uptime
`uptime` command parser
--url URL string parser
--ver Version string parser
--veracrypt
`veracrypt` command parser
--vmstat
`vmstat` command parser
--vmstat-s
`vmstat` command streaming parser
--w `w` command parser
--wc `wc` command parser
--who `who` command parser
--x509-cert
X.509 PEM and DER certificate file parser
--x509-csr
X.509 PEM and DER certificate request file parser
--xml XML file parser
--xrandr
`xrandr` command parser
--yaml YAML file parser
--zipinfo
`zipinfo` command parser
--zpool-iostat
`zpool iostat` command parser
--zpool-status
`zpool status` command parser
Options:
-a, --about
About jc (JSON or YAML output)
-C, --force-color
Force color output even when using pipes (overrides -m and the NO_COLOR env variable)
-d, --debug
Debug - show traceback (use -dd for verbose traceback)
-h, --help
Help (--help --parser_name for parser documentation). Use twice to show hidden parsers
(e.g. -hh). Use thrice to show parser categories (e.g. -hhh).
-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 print 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
-s, --slurp
Slurp multiple lines into an array. (use -hhh` to find compatible parsers)
-u, --unbuffer
Unbuffer output (useful for slow streaming data with streaming parsers)
-v, --version
Version information
-y, --yaml-out
YAML output
-B, --bash-comp
Generate Bash shell completion script
-Z, --zsh-comp
Generate Zsh shell completion script
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:
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
SlURP
Some parsers support multi-item input and can output an array of results in a single pass. Slurping works
for string parsers that accept a single line of input. (e.g. url and ip-address) To see a list of parsers
that support the --slurp option, use jc -hhh.
For example, you can send a file with multiple IP addresses (one per line) to jc with the --slurp option
and an array of results will output:
$ cat ip-addresses.txt | jc --slurp --ip-address
[<multiple output objects>]
The magic syntax for /proc files automatically supports slurping of multiple files (no need to use the
--slurp option). For example, you can convert many PID files at once:
$ jc /proc/*/status
[<multiple output objects>]
When the /proc magic syntax is used and multiple files are selected, an additional _file field is
inserted in the output so it is easier to tell what file each output object refers to.
Finally, the --meta-out option can be used in conjunction with slurped output. In this case, the slurped
output is wrapped in an object with the following structure:
{
"result": [<multiple output objects>],
"_jc_meta": {
"parser": "url",
"timestamp": 1706235558.654576,
"slice_start": null,
"slice_end": null,
"input_list": [
"http://www.google.com",
"https://www.apple.com",
"https://www.microsoft.com"
]
}
}
With --meta-out, input_list contains a list of inputs (actual input strings or /proc filenames) so you
can identify which output object relates to each input string or /proc filename.
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)
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
ENVIRONMENT
Custom Colors
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
Disable Color Output
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, ping-s, etc.) 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.
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",...}
{"type":"reply","pattern":null,"timestamp":null,"bytes":"64",...}
etc...
Note: Unbuffered output can be slower for large data streams.
PARSER PLUGINS
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
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. Any
dependencies can be placed in the jc folder above jcparsers and can be imported in the parser code.
Parser 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.
EXAMPLES
Standard Syntax:
$ dig www.google.com | jc -p --dig
$ cat /proc/meminfo | jc --pretty --proc
Magic Syntax:
$ jc --pretty dig www.google.com
$ jc --pretty /proc/meminfo
Line Slicing:
$ cat file.csv | jc :101 --csv # parse first 100 lines
For parser documentation:
$ jc --help --dig
More Help:
$ jc -hh # show hidden parsers
$ jc -hhh # list parsers by category tags
AUTHOR
Kelly Brazil (kellyjonbrazil@gmail.com)
https://github.com/kellyjonbrazil/jc
COPYRIGHT
Copyright (c) 2019-2024 Kelly Brazil
License: MIT License
1.25.1 2024-02-12 jc(1)