cheatsheet apolzek

Cheatsheet

commands and tricks for day to day

Delete All Commit History on GitHub gitgithub

Reset a repository's commit history by creating an orphan branch

git checkout --orphan latest_branch
git add -A
git commit -am "reset configs"
git branch -D main
git branch -m main
git push -f origin main

Send Text using ICMP networkicmp

Encode and send text payload via ping, receive and decode with tshark

# Send
payload=$(echo -n "Hello" | xxd -p)
echo $payload
len=$(($(echo $payload | wc -c | tr -s " ") + 2))
echo $len
ping -s$len -c4 -p$payload 127.0.0.1
# Receive
tshark -l -i lo0 -Y "icmp" -T fields -e data | xxd -r

Chrome Bookmarks (filter by folder) chromejqlinux

Extract URLs from a specific Chrome bookmark folder using jq

cat ~/.config/google-chrome/Default/Bookmarks \
  | jq -r '.roots.bookmark_bar.children[]
      | select(.name == "tree")
      | .children[]
      | select(.name == "blogs")
      | .children[]
      | .url'

Post-install Docker dockerlinux
Add current user to docker group after installation
```
sudo usermod -aG docker $USER
exec su -l $USER
groups $USER
docker ps
```

k6 Load Testing k6testingperformance

Basic k6 script with ramp-up, sustained load, and ramp-down stages

import http from 'k6/http';
import { sleep } from 'k6';

export const options = {
    stages: [
        { duration: '10s', target: 100 },
        { duration: '30s', target: 100 },
        { duration: '10s', target: 0 }
    ]
}

export default function () {
    http.get('http://192.168.68.108:3000');
    sleep(1);
}

ntfy Send Notification curlnotification
Send a push notification via ntfy.sh using curl
```
curl -d "Backup successful" ntfy.sh/mytopic
```
Convert Video for DaVinci Resolve ffmpegvideo
Convert MP4 to ProRes format compatible with DaVinci Resolve
```
ffmpeg -i input.mp4 -c:v prores -profile:v 3 -c:a pcm_s16le output.mov
```

Generate OpenTelemetry Traces opentelemetryobservability

Generate 200 traces in a loop using telemetrygen

for i in $(seq 1 200); do
  echo $i
  telemetrygen traces --otlp-insecure --traces 1 --service telemetrygen
  sleep 0.5
done

curl with --resolve curlnetwork

Force curl to resolve a hostname to a specific IP address, bypassing DNS

curl --resolve meuservidor.com:8080:192.168.0.100 http://meuservidor.com:8080
curl --resolve google.com:8888:127.0.0.1 https://google.com:8888

Chrome Internals Pages chromedebug
Useful chrome:// internal pages for debugging DNS, events, and proxy settings
```
chrome://net-internals/#dns
chrome://net-internals/#events
chrome://net-internals/#proxy
```

Write to Container stdout/stderr dockerlinuxdebug

Send a message directly to a container's stdout or stderr via /proc

# stderr (fd/2) or stdout (fd/1)
echo '2025/03/09 07:55:58 [emerg] 12345#0: unexpected "}" in /etc/nginx/nginx.conf:25' > /proc/1/fd/2

Windows Activation (massgrave) windowspowershell
Activate Windows using the massgrave open-source script
```
irm https://massgrave.dev/get | iex
```

View WiFi Passwords linuxwifinetwork

Retrieve saved WiFi passwords on Linux using NetworkManager

ls /etc/NetworkManager/system-connections/
sudo cat /etc/NetworkManager/system-connections/[network-name]
nmcli device wifi list
sudo nmcli connection show "" --show-secrets

Encrypt / Decrypt File with Password opensslsecuritylinux

Use OpenSSL AES-256-CBC with PBKDF2 to encrypt and decrypt files

# Encrypt
echo "Este é um arquivo de teste" > original.txt
openssl enc -aes-256-cbc -salt -pbkdf2 -in original.txt -out secreto.enc

# Decrypt
openssl enc -aes-256-cbc -d -salt -pbkdf2 -in secreto.enc

# Decrypt from remote URL
curl -s https://raw.githubusercontent.com/apolzek/apolzek.github.io/main/secreto.enc \
  | openssl enc -aes-256-cbc -d -salt -pbkdf2

Chrome Bookmarks (list all) chromejqlinux

List all bookmarks from Chrome's JSON file showing name and URL

cat ~/.config/google-chrome/Default/Bookmarks \
  | jq '.roots.bookmark_bar.children[] | {name: .name, url: .url}'

Linux Network Connections linuxnetwork
View all saved NetworkManager connection configs
```
sudo cat /etc/NetworkManager/system-connections/*
```