TIL

Today I Learned

Things I Learned today, found on Simon's Blog, and repo can be found here: Repo

187 TILs so far.

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Recently Added/Updated TILs

• Why All Users Can Write to /tmp

• Limit Upload Download Speeds in Rclone

• Convert String To Uppercase in Go

• Set Metric For A Network Using nmcli

• Docker Fix UFW Security Flaw

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Categories

• Linux

• Ansible

• Caddy

• Cheatsheets

• Docker

• Git

• Github

• Go

• Learning Resources

• Miscellaneous

• Python

• Rclone

• ReactJS

• Vagrant

• VSCode

• WSL

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Linux

• Add Swap Space To System
• Add User To System
• Beautify Logs
• Benchmark System
• Ccze Scrolling Output
• Change Default Shell
• Change Hostname Of A system
• Changing User Password In Shell Script
• Check Group Of A User
• Check If A Package Is Installed Or Not
• Check If A Port Is In Use
• Check If A User Exists
• Check Open Port
• CMake Parallel Build with All Cores
• Create Symbolic Links
• Determine Which Process Is Using a File
• Enable SSH Server
• Fix Permission For Newly Created Partitions
• Fix Windows And Linux Different Time Issue
• Get Arch Of System
• Increase Limit of Inotify Watchers
• Install Latest NodeJS In Linux
• Install Pavucontrol
• Install Postman
• Kill A Process In Linux
• Mount Partition On System Startup
• OpenVPN Server
• Ping over TCP
• Pipe Password to Sudo
• Remove PPA From System
• Remove User Password
• Root Check in Scripts
• Run Go Binaries Without Installing Go
• Set Different Time Zone
• Show Disk Usage By Directories
• Show Public IP
• Show Size of Current Directory
• System Ugprade
• Tar Exclude Directories
• Tar Retain File Permissions
• Why All Users Can Write to /tmp

Alpine Linux

• Adding User On Alpine
• Chaning Timezone On Alpine
• Installing Ansible On Alpine
• Installing Dig On Alpine
• Installing Pip On Alpine
• Installing Python2 On Alpine

Apt

• APT Fix Broken Packages
• APT Hold Packages From Upgrade

Arch Linux

• Install Docker Compose
• Install Docker
• Install Pip

Bash

• Bash List Only Directories
• BashTOP Resource Monitor
• Case Statements
• Concatenate Strings
• Custom Shell Prompt
• Length of String in Variable
• Test Regular Expression Against A String
• Pass Arguments while Piping
• Read Command Output In Reverse Order
• "set -e" In Scripts
• Set MacOS Like Terminal Font
• Set Unlimited Bash History
• Shell Formatter
• Yes

Curl

• Fix Failed Writing Body While Piping
• Use Proxy Server in cURL

Fedora

• Install RPM Packages in Fedora

GPG

• Fix "Inappropriate ioctl for device" Error
• GPG Import Keys
• GPG Test
• GPG Trust Key
• GPG Verify Signature

Grep

• Grep Case Insensitive Search
• Grep Count Occurance
• Grep Exact Match
• Grep Invert Search
• Grep On Continous Stream
• Grep Quiet Mode
• Grep Search For Multiple Strings
• Remove Empty Lines

Journalctl

• Get Errors in Running Services using Journalctl

Networking

• Install Dig
• Install MTR
• Set Metric For A Network Using nmcli
• WireGuard Server

Raspberry Pi

• Disable Swap Memory on SD Card

SSH

• Reconnect To a Disconnected SSH Session
• Run A Local Script On Remote SSH Server
• Screen
• Tmux

Systemd

• Create A Service
• Create A Systemd Timer
• List Systemd Services Of A User
• Prevent Systemd Timers From Overlapping
• Watch Systemd Service Status

Tcpdump

• Capture ICMP Packets
• Capture Traffic By IP Or A Network

Ubuntu Linux

• Get Clipboard History
• Install HMAC256 On Ubuntu
• Obtaining a List of Ubuntu Repository Mirror Servers

Wget

• Basic Authentication

Ansible

• Add Authorized SSH Key to User using Ansible
• Ansible Add User to System
• Ansible Configure Default Inventory File
• Ansible Disable Python Interpreter Warnings
• Ansible Pause Playbook Execution
• Ansible Test Connection
• Run Ansible Playbook Locally
• Setting a Password in Ansible Inventory File

Caddy Server

• Caddy Write Logs to a File
• Return Client IP Address As Plain Text

Cheatsheets

• Bash Cheatsheet
• Grep Cheatsheet
• Markdown Cheatsheet
• MongoDB Cheatsheet
• Networking Cheatsheet
• Python Cheatsheet
• ReactJS Cheatsheet
• Regex Cheatsheet

Docker

• Docker Build Multiple Tags At Once
• Docker Exec
• Docker Publish Port
• Docker Run Without Cache
• Docker Run
• Fix UFW Security Flaw
• Install Docker
• Install Ping in Docker
• Pass Build Time Arguments To Docker Build
• Remove Container When It Exits
• Remove Unused Data
• Run Docker without root
• Setup Docker Buildx For Multi Arch Builds

Git

• Change Last Commit Message
• Delete Tag
• Get Tag Names in Git
• Save Credentials for Remotes in Git
• Show Commit Only From One Author
• View Git Commit Changes

GitHub

GitHub Actions

• Setting An Environment Variable
• Running Jobs in a Container

Go

• Convert String To Uppercase in Go
• List All Possible GOOS And GOARCH
• Print Go Version
• Resolve Hostname To IP Address
• Trim Whitespaces From String
• Update Project Libraries To Latest

Learning Resources

• Algorithms
• DevOps
• Git
• Linux
• Networking
• Programming Languages

Miscellaneous

• Good Reads
• Must Read Sites
• Useful Sites

Python

• Add An Item To Dictionary
• Check If A Key Exists In Dictionary
• Check If a String is Empty
• Check Image Size
• Check Python Version Programmatically
• Convert List To Tuple
• Execute Python Code in Command Shell
• Formatted Strings
• Get IP Address From Hostname
• Limit Floating Point To Two Decimal Places
• Measure Latency Using TCP
• Pass List as Argument to a Function
• Print Tabular Data
• Python Padding Strings
• Read A File Line By Line
• Remove A File
• Remove Trailing Spaces And New Lines From A String
• Run Python Script in Background
• Split String with Delimiter
• Validate IP Address

Pipenv

• Install Dependencies System Wide
• Remove Virtualenv

Rclone

• Limit Upload Download Speeds in Rclone

ReactJS

• ReactJS Resources

Vagrant

• Increase RAM And CPU On Vagrant Machine
• Vagrant Specify Disk Size

VSCode

• Install VS Code on a Linux Server

WSL

• Convert WSL1 to WSL2
• Enable Systemd Support in WSL2