Today I Learned

Table of Contents

• Today I Learned
  • Table of Contents
  • Categories
    • ack
    • afplay
    • ag also known as the Silversurfer - fast alternative to ack and grep
    • Bash
    • Bootstrap
    • carton
    • chezmoi - dot filer manager
    • chrome
    • clang
    • colortail - colorfull variation of tail
    • CPAN - Perl Packages
    • cpanm
    • crates - Rust packages
    • css
    • curl
    • Dash.app
    • date
    • Debian
    • diff-so-fancy
    • DigitalOcean
    • Docker
    • DockerHub
    • Dropbox
    • dzil
    • EditorConfig
    • entr - run arbitrary commands when files change
    • exa - an alternative to the ls command
    • FileMerge.app
    • find
    • Git
    • git-delta - an commandline diff tool, also known as delta
    • GitHub
    • GitHub Actions - automate your GitHub work and repositories
    • GnuPG
    • Go
    • grep - see also ag also known as silversurfer
    • Hacking
    • Homebrew
    • HTML
    • httpie - an alternative to curl
    • irssi - for all your IRC needs
    • iTerm.app - an alternative to Terminal.app
    • JavaScript
    • Jenkins
    • Jira
    • jq - a lightweight and flexible command-line JSON processor
    • JSON - see also XML and YAML
    • Kali
    • Liquid Prompt - see also Starship
    • Mail.app
    • Markdown
    • markdownlint
    • Mermaid
    • Mojolicious
    • MySQL
    • Oracle
    • OpenSSL
    • OSX
    • Perl
    • Perlbrew
    • Perltidy - tidy all your Perl
    • Postgresql
    • Programming
    • Probot
    • Prolog
    • Python
    • qalc - an easy to use command line calculator
    • REST
    • rm
    • Ruby
    • Rust
    • sed
    • shellcheck
    • Slack
    • smartcd
    • Sublime Text 3 - see also VSCode
    • Subversion - do see Git
    • SQL
    • SQL Developer
    • SQLite
    • sqlplus - the CLI tool for Oracle
    • SSH
    • Starship - nifty prompt and an alternative to Liquid Prompt
    • Swift
    • tar
    • Terminal.app - do see iTerm.app
    • tldr - Too Long; Didn't Read, so use tldr
    • tmux - an alternative to screen
    • tokei - language statistics - fast
    • Ubuntu
    • VSCode / Visual Studio Code
    • VMware Fusion
    • Vue
    • WSL 1/2
    • wtf util
    • XML - see also YAML and JSON
    • YAML - see also XML and JSON
    • z - for jumping around in the commandline
    • zsh - another shell than bash
  • About
  • Additional TIL Collections
  • License

Categories

ack

• Install ack
• Define a custom search filetype scope

afplay

• RTFM

ag also known as the Silversurfer - fast alternative to ack and grep

• Use ag

Bash

• Use bash
• Implement tab completions
• Inputting danish characters
• Repeating an executable continuously
• Slimming history
• Reading arguments from the command line
• Copy a file to multiple directories
• Replace a file in multiple directories
• Create directory for own bash completions
• Edit Complex CLI in Editor
• Use fzf
• Use Colours In Terminal Output
• How to get last return value
• Getting Process-id of a Child Proces
• Grep STDERR
• Use Bashmarks
• Use z
• Write safe shell scripts
• Glob expanding to all files in current directory recursively

Bootstrap

• Prevent wrapping of contents of code tags

carton

• Use carton
• Pass flags to arguments to exec
• Update snapshot cpanfile
• Use PERL_CARTON_MIRROR

chezmoi - dot filer manager

• Install chezmoi
• Use chezmoi

chrome

• Add search shortcuts

clang

• Diagnostic flags in Clang

colortail - colorfull variation of tail

• use colortail

CPAN - Perl Packages

• Use CPAN
• Data::FormValidator
• File::Find
• Test::Pretty
• Parsing Gitignore

cpanm

• Use cpanm
• Use cpanm with cpanfile
• Use cpanm with Module::Build
• Use cpanm with CPAN::Mini
• Use cpanm with carton
• Tailing cpanm build log file

crates - Rust packages

• colored

css

• Making sure you are using alt tags
• CSS Properties

curl

• More POST Parameters
• Handling shell sensitive characters in URL
• Pipe output to less
• Use a cheatsheet
• Using curl with Graphql server
• Specify method
• Get statuscode

Dash.app

• Query Dash from the CLI

date

• Getting time in another timezone

Debian

• How to enquire version
• Add user to sudoers group
• Resolve conflicting values in Debian package
• Install unauthenticated package
• Translate release names

diff-so-fancy

• use diff-so-fancy
• One-time Disable of diff-so-fancy for Git

- a hosting provider, caring about open source

DigitalOcean

• Monitor billing
• Use doctl
• Serving Static Files From a Go App

Docker

• Use Docker
• Mount shared folder
• Use shell to inspect filesystem of layer
• How to read files and stdout from a running docker container
• Use ctop
• Define default network addresses used for containers
• Copy a file from your container to the host operating system
• Caching Docker build step
• Show layers of Docker image
• What is the difference between RUN and CMD
• Automatically Clean up after Docker Daily
• Customize your docker ps output
• Use docker-compose-wait
• Silence Warnings from Postgres
• Debugging a b0rken Docker build step
• exec error
• Docker on Windows

DockerHub

• Publish an image to DockerHub
• Use Long Names for Your Base Images
• Use hub-tool

Dropbox

• Download instead of playing multimedia file from Dropbox
• Ignore certain files

dzil

• Make coverage tests
• Use cpanfile
• Run a single test

EditorConfig

• Use EditorConfig
• Enforce EditorConfig using eclint
• Perl
• XML
• Markdown

entr - run arbitrary commands when files change

• Run arbitrary commands when files change using entry

exa - an alternative to the ls command

• Use exa

FileMerge.app

• User Filemerge from the commandline

find

• Searching Found Files in Found Directories

Git

• Resolve conflicts involving binary files
• Delete local and remote branch
• Set your email for a repository
• Delete local and remote tags
• Create a branch from a tag
• Correct a commit message
• Update a branch from master
• Rename branch
• Get a cheatsheet
• Update fork from original repository
• Tag a specific revision
• Make a branch new master
• List merged branches
• Git Alias to Show Affected Files in Last N Commits
• Output your branches and tags as a tree on the command line
• Compare a single file between branches
• Rollback a repository to a specific commit
• Avoid being prompted for password
• Rename a tag
• Rewrite the last commit message
• Use Git Repository Viewer: grv
• Use tig
• Update submodule
• Squash merge
• Maintain Multiple Git Identities
• Find Out Who Created a Branch
• See a given file at a given commit
• Create a branch from an older commit
• Get Name of Current Branch
• Use pre-commit
• Ignore Git

git-delta - an commandline diff tool, also known as delta

• Use git-delta

GitHub

• Ignore whitespace changes
• Test Markdown rendering before making public
• How to get the email address of a github user
• Use hub
• Use emojis
• GitHub Action Badges
• Use dependabot
• Providing Suggestions in Reviews
• Use CLI

GitHub Actions - automate your GitHub work and repositories

• Use spellcheck
• Use macOS
• Use EditorConfig
• Schedule runs
• Use Dependabot for GitHub Actions
• Use Dependabot for Docker
• Use Dependabot for Ruby
• Use Dependabot for Python

GnuPG

• Homebrew GnuPG vs. GPG Mail

Go

• Learn Go
• Go Resources
• Reading Documentation
• Reading benchmark results
• Skipping tests
• Colorful test output
• How to sleep
• Test Main Function
• Get to know the standard library
• structs
• Running specific tests
• Read from STDIN
• Use gocritic
• Working with local packages
• Panic: Flag redefined

grep - see also ag also known as silversurfer

• Add colour to grep output

Hacking

• Change password on Window 7 Using Kali Linux
• Wipe a Hard Drive Using Kali Linux

Homebrew

• Stop brew from calling home
• Cleaning your homebrew cellar
• Installing bash
• Migrate installation
• Remove tap

HTML

• Add and Remove classes using JavaScript
• Execute JavaScript from a button
• How Can I Get HTML value using JavaScript

httpie - an alternative to curl

• Use httpie
• Using httpie with Graphql server

irssi - for all your IRC needs

• Use password authentication on Freenode

iTerm.app - an alternative to Terminal.app

• Use themes

JavaScript

• Use a styleguide
• Beware of eval
• Default Parameters for Functions
• Learn JavaScript

Jenkins

• Use a script for freestyle projects

Jira

• Get a List of Linked Issues
• How to escape curly brackets within code tags

jq - a lightweight and flexible command-line JSON processor

• Use jq

JSON - see also XML and YAML

• Beware of eval
• Check out JSON Schema
• Prettify JSON on the command line

Kali

• Set Keyboard Layout

Liquid Prompt - see also Starship

• Install Liquid Prompt

Mail.app

• Mail file from the commandline

Markdown

• Use Markdown
• How do I escape a backtick
• How do I escape a numbersign
• How do I escape asterisk and other characters
• Read Markdown in terminal
• Use Markdownlint

markdownlint

• Issue with enabledrules

Mermaid

• Diagram with Mermaid

Mojolicious

• Redirecting from one URL to another
• Setting up a new application
• Enable logging
• Mojolicious::Controller respond_to and template parameter
• Enable syntax highlighting for configuration files

MySQL

• Setting the prompt

Oracle

• Convert string to date
• ORA-21561: OID generation failed
• Beware of force for creation
• How to see Oracle version
• Executing a function or procedure
• Comments in tnsnames.ora
• See grants for a specific user
• See What a Record Looked Like

OpenSSL

• How to get information from a P12 file

OSX

• Lock screen shortcuts
• Speak when long running job is done
• List available voices for speechsynthesis
• Set hostname permanently
• Access iCloud from the cli
• Install Homebrew
• Debugging Issues with Dynamic Libraries
• Uninstall MacPorts
• Scheduling Timed Jobs
• Enabling at
• Playing Sound from the Command Line
• Keyboard Symbols
• Use JavaScript
• Set Default Browser From the Command Line
• No telnet use netcat
• What ports are listened on
• Reset Bluetooth
• Inspecting dynamic libraries
• Install OpenSSL using MacPorts

Perl

• View generated SQL when using DBIx::Class
• Create Test Coverage Report Using Dist::Zilla
• Avoid issues with META.yml with Module::Install
• Install XML::LibXML on MacOS
• Get ExtUtils::MakeMaker to install in local/ like carton
• Mojolicious::Plugin::OpenAPI Tutorial
• Read Input via Pipe
• Find out if a given Perl distribution is included in core
• Find out what your perl minimum version requirement is

Perlbrew

• Install perlbrew
• Eliminate compilation warnings on OSX
• Uninstall perlbrew
• Install a new perl and clone modules from an existing installation

Perltidy - tidy all your Perl

• Tidy a file inline

Postgresql

• Setting the prompt

Programming

• Round float to 2 decimals

Probot

• Probot: auto-assign
• Probot: delete merged branch
• Probot: todo

Prolog

• Prolog resources

Python

• Old-school string formatting
• What is wheel

qalc - an easy to use command line calculator

• Calculate Download Time
• Eliminate Locale Warnings

REST

• Prototype with dummy APIs
• Use proper headers
• Check out OpenAPI
• Use verbs

rm

• Delete files with names resembling cli options

Ruby

• Dump objects attributes

Rust

• Setting Up a Rust Development Environment
• What is an empty parens
• Get a Cheatsheet
• Installing Dependencies
• Learn Rust
• Formatting code
• Declaring a constant

sed

• Test Command Using echo
• Remove empty lines
• Remove comments
• Chaining actions

shellcheck

• Use shellcheck
• Ignore shellcheck error

Slack

• Mark all as read

smartcd

• Install smartcd
• Use smartcd with tabs
• Silence smartcd

Sublime Text 3 - see also VSCode

• Set colour scheme per language

Subversion - do see Git

• Do something with every repository
• See in what revision a branch was created
• Use Filemerge as diff tool
• Use commit message from file

SQL

• Counting NULL and non-NULL values in a single query
• How to group by month in a year
• How to query data where you are unsure of the casing

SQL Developer

• Setting UI fontsize
• Setting dateformat
• View Compilation Log
• Creating folders
• View text instead of Worksheet

SQLite

• Emulate schemas
• Inserting dates
• Defaulting to now for date

sqlplus - the CLI tool for Oracle

• Output to a file
• How to pass hostname and port parameters

SSH

• Permissions on SSH folder and files

Starship - nifty prompt and an alternative to Liquid Prompt

• Use Starship
• Increase Interval for Slow Commands

Swift

• Learn Swift

tar

• Using tar

Terminal.app - do see iTerm.app

• Opening files in an application from the command line

tldr - Too Long; Didn't Read, so use tldr

• use tldr

tmux - an alternative to screen

• Use tmux
• Install tmux
• Standard Layouts
• Use tmux Resurrect
• Use tmux plugin manager

tokei - language statistics - fast

• use tokei

Ubuntu

• Install updates via command line
• How to enquire version
• Translate release names

VSCode / Visual Studio Code

• Stop vscode from calling home
• Integrate vscode with Shell / CLI
• Synchronize Setttings across machines
• Use Markdownlint
• Todo Tree Extension
• Issue with integrated terminal on macOS
• Themes

VMware Fusion

• Install VMware Tools
• Configure Debian 7

Vue

• Get Started with Vue

WSL 1/2

• Configure Git
• Developing in Visual Studio Code
• Up and Downgrade WSL
• bashrc not being sourced

wtf util

• Play around with wtf

XML - see also YAML and JSON

• Avoid entity expansion
• Fast XML/XSD validation on the command line

YAML - see also XML and JSON

• How to syntax check a YAML file

z - for jumping around in the commandline

• Jumping Around Using z

zsh - another shell than bash

• Use zsh
• Set Environment from File

About

I have for a long time maintained notes in a public wiki, finding the TIL of Josh Branchaud jbranchaud/til was an eye-opener and I immiediately wanted to try it out, so after a few months I have finally set it up.

I plan to migrate my earlier notes, so they are more easily accessible here as TIL snippets, this will be done when I have the time, one TIL at a time :-)

Additional TIL Collections

• Today I Learned by Hashrocket
• jwworth/til
• thoughtbot/til

License

© 2016-2022 jonasbn

This repository is licensed under the MIT license. See LICENSE file for details. Much is lifted from elsewhere and might by copyrighted under other licenses by the respective authors. I will mention this where applicable and I will link to original sources when and if possible.