prefix

README

prefix

🔴 prepend numbers, stats, dates, durations to streams

Usage

foo@bar:~$ prefix -h
USAGE
  prefix [flags] file

FLAGS
  -format string
    	format string (default "{{DEFAULT}} ")

SYNTAX
  {{.Duration | short_duration}}      {{.Duration}} displayed in a pretty & short format (len<=7)
  {{.Duration}}                       time since previous line was started
  {{.Format}}                         the value you set with -format
  {{.LineNumber3}}                    alias for {{printf "%-3d" .LineNumber}}
  {{.LineNumber4}}                    alias for {{printf "%-4d" .LineNumber}}
  {{.LineNumber5}}                    alias for {{printf "%-5d" .LineNumber}}
  {{.LineNumber}}                     display line number
  {{.ShortDuration}}                  alias for {{.Duration | short_duration}}
  {{.ShortUptime}}                    alias for {{.Uptime | short_duration}}
  {{.Uptime | short_duration}}        {{.Uptime}} displayed in a pretty & short format (len<=7)
  {{.Uptime}}                         time since the the prefixer was initialized
  {{env "USER"}}                      replace with content of the $USER env var
  {{now | unixEpoch}}                 current timestamp
  {{now}}                             current date (format: 2006-01-02 15:04:05.999999999 -0700 MST)
  {{uuidv4}}                          UUID of the v4 (randomly generated) type

  the following helpers are also available:
  - from the text/template library    https://golang.org/pkg/text/template/
  - from the sprig project            https://github.com/masterminds/sprig#usage

PRESETS
  {{DEFAULT}}          {{.LineNumber3}} up={{.ShortUptime}} d={{.ShortDuration}} |
  {{SHORT_DATE}}       {{now | date "06/02/01 15:04:05"}}
  {{SLOW_LINES}}       {{if (gt .Duration 1000000000)}}SLOW{{else}}    {{end}} {{.Duration | short_duration}} 

EXAMPLES
  prefix apache.log
  prefix -format=">>>" apache.log
  tail -f apache.log | prefix -
  my-cool-program 2>&1 | prefix -format="#{{.LineNumber5}} " -

foo@bar:~$ generate-fake-data | prefix -format="#{{.LineNumber3}} {{.ShortUptime}} {{.ShortDuration}} | "
#1   73.6µs  80.9µs  | At illum ut est sit soluta nulla numquam.
#2   112ms   111.9ms | Sunt quaerat ea dolores facere deleniti culpa numquam.
#3   327.1ms 215.1ms | Distinctio maxime consequatur est qui corporis sunt officia.
#4   605.3ms 278.2ms | Et quia odit molestias voluptas porro repellendus magnam.
#5   897.7ms 292.3ms | Corporis eos rem non hic esse optio quisquam.
#6   1.1s    211.7ms | Natus earum molestias iste architecto porro et blanditiis.
#7   1.3s    238.2ms | Eum repellendus nostrum qui eius suscipit fugit quia.
#8   1.4s    50.6ms  | Et nesciunt quod fuga ut vel pariatur libero.
#9   1.6s    209.6ms | Rerum omnis soluta facilis voluptatem possimus et voluptas.
#10  1.9s    274.7ms | Possimus harum voluptatibus aperiam voluptatibus qui autem quam.

foo@bar:~$ generate-fake-data | prefix -format="{{.LineNumber3}} "
1   At illum ut est sit soluta nulla numquam.
2   Nobis sunt quaerat ea dolores facere deleniti culpa.
3   Numquam ut distinctio maxime consequatur est qui corporis.
4   Sunt officia odit et quia odit molestias voluptas.
5   Porro repellendus magnam ipsa corporis eos rem non.
6   Hic esse optio quisquam hic natus earum molestias.
7   Iste architecto porro et blanditiis iste eum repellendus.
8   Nostrum qui eius suscipit fugit quia quo et.
9   Nesciunt quod fuga ut vel pariatur libero sequi.
10  Rerum omnis soluta facilis voluptatem possimus et voluptas.

foo@bar:~$ generate-fake-data | prefix -format=">>> "
>>> At illum ut est sit soluta nulla numquam.
>>> Nobis sunt quaerat ea dolores facere deleniti culpa.
>>> Numquam ut distinctio maxime consequatur est qui corporis.
>>> Sunt officia odit et quia odit molestias voluptas.
>>> Porro repellendus magnam ipsa corporis eos rem non.
>>> Hic esse optio quisquam hic natus earum molestias.
>>> Iste architecto porro et blanditiis iste eum repellendus.
>>> Nostrum qui eius suscipit fugit quia quo et.
>>> Nesciunt quod fuga ut vel pariatur libero sequi.
>>> Rerum omnis soluta facilis voluptatem possimus et voluptas.

foo@bar:~$ generate-fake-data | prefix -format="{{SLOW_LINES}} up={{.ShortUptime}} | "
     876.7µs  up=892.6µs | Rerum natus quo quo explicabo tempore et delectus.
SLOW 1s       up=1.1s    | Dolor blanditiis voluptas dolorum sint laudantium eveniet amet.
SLOW 1.3s     up=2.4s    | Qui asperiores molestiae est quia est eum omnis.
SLOW 1.3s     up=3.6s    | Illum explicabo aut illum iste pariatur aut laudantium.
     982.2ms  up=4.6s    | Quibusdam asperiores consequatur est dolores quas dolor ipsam.
     185.5ms  up=4.8s    | Possimus qui non rem qui cum sit temporibus.
     167.5ms  up=5s      | Ea debitis sit deleniti cum ut adipisci in.
     520.3ms  up=5.5s    | Eveniet molestias voluptatem voluptatem deserunt nisi tempora iusto.
     215ms    up=5.7s    | Fugiat minus quam eos voluptatem labore sit velit.
SLOW 1s       up=6.7s    | Enim aut autem tenetur fugit minima quo atque.

foo@bar:~$ generate-fake-data | prefix -format="{{SHORT_DATE}} "
20/19/09 00:02:43 At illum ut est sit soluta nulla numquam.
20/19/09 00:02:44 Sunt quaerat ea dolores facere deleniti culpa numquam.
20/19/09 00:02:45 Distinctio maxime consequatur est qui corporis sunt officia.
20/19/09 00:02:46 Et quia odit molestias voluptas porro repellendus magnam.
20/19/09 00:02:48 Corporis eos rem non hic esse optio quisquam.
20/19/09 00:02:49 Natus earum molestias iste architecto porro et blanditiis.
20/19/09 00:02:50 Eum repellendus nostrum qui eius suscipit fugit quia.
20/19/09 00:02:50 Et nesciunt quod fuga ut vel pariatur libero.
20/19/09 00:02:51 Rerum omnis soluta facilis voluptatem possimus et voluptas.
20/19/09 00:02:53 Possimus harum voluptatibus aperiam voluptatibus qui autem quam.

Install

Using go

$ go get -u moul.io/prefix

Releases

See https://github.com/moul/prefix/releases

Contribute

I really welcome contributions. Your input is the most precious material. I'm well aware of that and I thank you in advance. Everyone is encouraged to look at what they can do on their own scale; no effort is too small.

Everything on contribution is sum up here: CONTRIBUTING.md

Contributors ✨

Thanks goes to these wonderful people (emoji key):

Manfred Touron 🚧 📖 ⚠️ 💻

moul-bot 🚧

This project follows the all-contributors specification. Contributions of any kind welcome!

Stargazers over time

License

© 2020-2021 Manfred Touron

Licensed under the Apache License, Version 2.0 (LICENSE-APACHE) or the MIT license (LICENSE-MIT), at your option. See the COPYRIGHT file for more details.

SPDX-License-Identifier: (Apache-2.0 OR MIT)

Documentation

Overview

message from the author:

+--------------------------------------------------------------+
| * * * ░░░░░░░░░░░░░░░░░░░░  Hello  ░░░░░░░░░░░░░░░░░░░░░░░░░░|
+--------------------------------------------------------------+
|                                                              |
|     ++              ______________________________________   |
|     ++++           /                                      \  |
|      ++++          |                                      |  |
|    ++++++++++      |   Feel free to contribute to this    |  |
|   +++       |      |       project or contact me on       |  |
|   ++         |     |    manfred.life if you like this     |  |
|   +  -==   ==|     |               project!               |  |
|  (   <*>   <*>     |                                      |  |
|   |          |    /|                  :)                  |  |
|   |         _)   / |                                      |  |
|   |      +++    /  \______________________________________/  |
|    \      =+   /                                             |
|     \      +                                                 |
|     |\++++++                                                 |
|     |  ++++      ||//                                        |
|  ___|   |___    _||/__                                     __|
| /    ---    \   \|  |||                   __ _  ___  __ __/ /|
|/  |       |  \    \ /                    /  ' \/ _ \/ // / / |
||  |       |  |    | |                   /_/_/_/\___/\_,_/_/  |
+--------------------------------------------------------------+

Index

• Variables
• type LinePrefixer
  • func New(format string) LinePrefixer

Variables

var AvailablePatterns = map[string]string{
	`{{.LineNumber}}`:                `display line number`,
	`{{.LineNumber3}}`:               `alias for {{printf "%-3d" .LineNumber}}`,
	`{{.LineNumber4}}`:               `alias for {{printf "%-4d" .LineNumber}}`,
	`{{.LineNumber5}}`:               `alias for {{printf "%-5d" .LineNumber}}`,
	`{{.Format}}`:                    `the value you set with -format`,
	`{{.Uptime}}`:                    `time since the the prefixer was initialized`,
	`{{.Duration}}`:                  `time since previous line was started`,
	`{{.Uptime | short_duration}}`:   `{{.Uptime}} displayed in a pretty & short format (len<=7)`,
	`{{.Duration | short_duration}}`: `{{.Duration}} displayed in a pretty & short format (len<=7)`,
	`{{now}}`:                        `current date (format: 2006-01-02 15:04:05.999999999 -0700 MST)`,
	`{{now | unixEpoch}}`:            `current timestamp`,
	`{{uuidv4}}`:                     `UUID of the v4 (randomly generated) type`,
	`{{env "USER"}}`:                 `replace with content of the $USER env var`,
	`{{.ShortDuration}}`:             `alias for {{.Duration | short_duration}}`,
	`{{.ShortUptime}}`:               `alias for {{.Uptime | short_duration}}`,
}

AvailablePatterns is the list of available patterns to be used by the user.

This variable is only used to generate usage.

var AvailablePresets = map[string]string{
	"{{DEFAULT}}":    `{{.LineNumber3}} up={{.ShortUptime}} d={{.ShortDuration}} |`,
	"{{SLOW_LINES}}": `{{if (gt .Duration 1000000000)}}SLOW{{else}}    {{end}} {{.Duration | short_duration}} `,
	"{{SHORT_DATE}}": `{{now | date "06/02/01 15:04:05"}}`,
}

AvailablePresets is the list of available presets.

Those presets are automatically replaced during the initialization of the prefixer.

Types

type LinePrefixer

type LinePrefixer interface {
	PrefixLine(string) string
}

func New

func New(format string) LinePrefixer

New returns an initialized LinePrefixer.