Awesome

Monaλog

Monalog is terminal logs observer.

Demo

Installation

Clone the repo
run cabal install exe:monalog
Enjoy

Running

monalog --help
Usage: monalog [COMMAND | [FILE] [-f|--format FORMAT] [-d|--default-field FIELD]
                 [-c|--config CONFIG] [-i|--ignore-config ARG]]

Available options:
  FILE                     The format can be derived from the file format. If
                           the file format is .csv, the output will be csv,
                           otherwise it will be json.
  -f,--format FORMAT       Supported formats: json, csv. In the case of csv, the
                           first line is considered the header.
  -i,--ignore-config ARG   Expected values: global, local, all
  -h,--help                Show this help text

Available commands:
  config                   Work with config

monalog my_logs.json
# or 
monalog my_logs.csv
# or
run_logging_server | monalog --format=csv 
# or
run_logging_server | monalog --format=json

Usage

Hot key	Action
`Ctrl + q`	Cleanup logs
`Ctrl + d`	Exit
`t`	Go to top
`b`	Go to bottom
`g`	Go to
`h`, `left`	Shift left
`H`, `Shift + left`	Long shift left
`l`, `right`	Shift right
`L`, `Shift + right`	Log shift right
`j`, `up`	Shift up
`J`, `Shift + up`	Long shift up
`k`, `down`	Shift down
`K`, `Shift + down`	Long shift down
`s`	Select top line log
`scroll`	Shift up/down
`Ctrl + scroll`	Shift left/right

NOTE: some combinations with Ctrl and Shift can be handled by your terminal

Mouse is fully supported. You can

click buttons (all text within [..])
move fields and log entry view bounds.
move columns with < > buttons around header
activate query / jsonpath / editors
move horizontal view ports

Query language

Operators	Details
`=` , `!=`
`>`, `<`	Compares `number` with `number`, `string` with `string`, `bool` with `bool`. Otherwise returns `false`
`>=`, `<=`	Exactly `>`/`<` or `=`
`&&`, `\|\|`	Works with `bool`. For operands of other types returns `false`
`not`	Negates argument
`like`	Fuzzy text comparison
`in`	Checks if left operand is element of list in right operand`

Literal	Example
number	`5`, `34.2`, `-42`
string	`"foo"`, `"foo \"hello\""`
bool	`true`, `false`
array	`[1, true, "bar"]`
key	`_42foo`, `fOooBar`, `$"any \"string\" 1"`

Copying

Monalog supports two way to copy data:

Native. Monalog calls platform specific commands (which can be overwritten with config). Default commands:
OS Command
Macos pbcopy
Windows clip
Linux xclip -sel clip
Osc52. Check out if your terminal supports OSC52

OS	Command
`Macos`	`pbcopy`
`Windows`	`clip`
`Linux`	`xclip -sel clip`

Copying is available in log entry view using [Copy] button

Log view

Log view supports jsonpath queries. Jsonpath filter can be disabled/enabled with checkbox

Fields view

Monalog automatically detects fields appear in your logs. Fields view supports 2 display mods

Flatten
Nested

which can be toggled with button [Nested]/[Flatten]

Input formats

Format	Details
json	Means `jsonlines`. If line is not valid JSON then line is put to default field of JSON ( `{ "message": "some invalid json" }` ). Default field is `message` but can it be overwritten via cli or config
csv	The first line is supposed to be header

Config

By default monalog tries load config monalog.yaml from $PWD. You can disable it with -i or --ignore-config You can also specify path to config with -c or --config Here is example of monalog config:

fields:
  - "@timestamp" # builtin field. Indicates the time when monalog get log line
  - "@raw" # builtin field. Indicates whole log json
  - foo.bar 
format: csv # csv / json
defaultField: data.msg # useful for json only 
copyMethod: native # native / osc52
copyCommand: "xclip -sel clip"

Monalog can create config automatically

monalog config create --global # creates global config
monalog config create # creates local config

To find out where is config located use the following command

monalog config path global

To get more info use --help

Thanks to @ShrykeWindgrace for help with Windows support implementation