jsonlog

A command line tool that simplifies parsing json data type logs.

usage

# json logs
cat <<EOT > json.log
{ "name": "json", "value": 1 }
{ "name": "log", "value": 3 }
{ "name": "demo", "value": 5}
EOT
# use --disp(-d for short) to define the data output template
# use '{}' curly braces to wrap output field expression
jsonlog json.log -d '{name}\t{value + 1}'
# ---------output---------
# json  2
# log	  4
# demo  6
# ------------------------
# use the pipe operator to get stdin as input
cat json.log | jsonlog -d '{name}\t{value + 1}'
# use --index(-i for short) to jump lines
# use --num(-n for short) to limit lines
jsonlog json.log -d '{name}' -i 1 -n 1
# ---------output---------
# log
# ------------------------
# use the --cond(-c for short) to filter rows that satisfy the condition
jsonlog json.log -d '{name}' -c 'value > 1'
# ---------output---------
# log
# demo
# ------------------------
# use --out-sep(-j for short) to change the default output seperator
jsonlog json.log -d '{name}' -c 'value > 1' -j '\t'
# ---------output---------
# log	demo
# ------------------------

# error handling
echo '{name: "error"}' >> json.log
jsonlog json.log -d '{name}' -e '{data::error}'
# ---------output---------
# json
# log
# demo
# key must be a string at line 1 column 2
# ------------------------
# output only error lines
jsonlog json.log -e '{data::row}'
# ---------output---------
# 4
# ------------------------

installation

On Mac

# use homebrew
brew tap fefit/jsonlog
brew install jsonlog
# donwload the binary file
curl -OL https://github.com/fefit/jsonlog/releases/download/v0.1.0/jsonlog-mac-0.1.0.tar.gz -o jsonlog.tar.gz
tar -zxvf jsonlog.tar.gz
mv jsonlog /usr/local/bin

On linux

curl -OL https://github.com/fefit/jsonlog/releases/download/v0.1.0/jsonlog-linux-0.1.0.tar.gz -o jsonlog.tar.gz
tar -zxvf jsonlog.tar.gz
sudo mv jsonlog /usr/local/bin

cli options

argument	short	description
--disp	-d	The successfully parsed json data item output template, use {} to wrap expressions, in expression, variables with name from the json data's keys can be used.
--cond	-c	Filter the items that satisfy the condition expression.
--err-disp	-e	Error data output template, the error message will be injected in the data::error variable.
--off-err-cond	-o	Do not use condition filter for error data item.
--sep	-s	The seperator of the input json data logs, default is \n, one log per line, if it's not \n, it will parsed as a regex.
--out-sep	-j	The seperator of the output data, default is \n
--sep-max	-m	If the --sep is not \n, it will use it as a regex to split the input json data logs, this parameter specifies the maximum number of characters that can be matched by the split regex, e.g. --sep '\n\t', the \n\t will match a fixed two charcters, then you can set --sep-max 2.
--index	-i	The data item starting number index, default 0, use this argument to jump the starting lines
--num	-n	The maximum number of the input json data log items.

expressions

jsonlog uses the awesome crate evalexpr to provide expression support, so the builtin expression syntax and functions are supported, in addtion, some built-in data-related variables and methods are provided.

keyword	type	--cond	--disp	--err-disp	description
data::has_key(string, ...string)	function	✓	✓	✓	judge if the json data item has the specified keys.
data::row	variable	✓	✓	✓	the row number of the json data item, becareful to use only when needed, it will affect part of the parallel performance.
data::error	variable	x	x	✓	show the json parsing error of the error data item.
string::find(haystack, search, [index])	function	✓	x	x	find the position of the search string in the haystack

More functions please see the crate evalexpr's README

Questions & Bugs?

Welcome to report to us with issue if you meet any question or bug. Issue

License

MIT License.