1. Are you tired of entering your password for sshing into a remote server?
2. Are you tired of verifying host fingerprint changes every time?

Use this golden ssh command and save your valuable time

ssh -o "StrictHostKeyChecking no" -i ~/Documents/identify root@ip
echo "y\n" | HOSTNAME=`hostname` ssh-keygen -t rsa -C "$HOSTNAME" -f "$HOME/.ssh/id_rsa" -P ""
# copy key to remote
ssh-copy-id userid@hostname
sshpass -p pass ssh root@ip

You can use the @reboot keyword in crontab to start a shell script at system startup but here is why this isn’t a very good solution to do that.

The problem is that if you don’t shut down the system cleanly on the next startup this message will pop up and cron will simply skip over running your command.

"Skipping @reboot jobs -- not system startup"

The solution is easy, just use a systemd service.

/etc/systemd/system/service_name.service
------------------------------------------
[Unit]
Description=some description
After=network.target
StartLimitIntervalSec=0

[Service]
Type=simple
User=root
ExecStart=/home/user/script.sh

[Install]
WantedBy=multi-user.target

UnixDaemon – How Does Cron Reboot Work

Regex, Sed, and AWK are freaks in programming but they are pretty simple, well not at the beginning though.

Here I summarize some of the most amazing ones for RegEx

1. To Be or Not To Be, is possible with: LookAround
2. Stop Worrying! Regex101 is all you need to know

Here I list cool bash tricks I learned:

– Bash Heredoc

Ok the title is a bit long but why google create such a nice debug interface and make it so difficult to access it.

1. open chrome with remote debug enabled

chromium --remote-debugging-port=9222 https://github.com/

2. Install websocat to create websocket to chrome

sudo pacman -S websocat

3. Find magic chrome ws url. To do that visit following url

http://127.0.0.1:9222/json/list

4. Connect to the websocket

websocat ws://127.0.0.1:9222/devtools/browser/<GUID>

5. Execute magic command. Here just scrolling the page

{"id": 1, "method": "Runtime.evaluate", "params": {"expression": "document.documentElement.scrollTop = 600"}}

Few Notes

• Websocket URL directly from chrome(stdout) don’t address any target page. Stick to http://127.0.0.1:9222/json/list or see cdp tutorial for further information.
• For automated command execution in debug session you can use following scripting

  chrome_loop.sh
  inotifywait -q -m -e close_write cmd | 
  while read -r filename event; do 
       cat cmd | websocat -n1 ws://127.0.0.1:9222/devtools/page/<GUID>
  done

  cmd
  {"id": 1, "method": "Runtime.evaluate" , "params": {"expression": "alert('hi')"}}