Siva Dhayalan

These are just reminders/documentation for me because I don’t want to remember them. It is not a guide for anything, it just has commands and tricks I use when reinstalling OS or fixing someone’s computer. Please don’t copy/paste commands without knowing what they do.

• GNU/Linux

  • install and setup nnn, a cli file manager

      sudo apt install nnn
      sudo apt install moreutils
      sudo apt install renameutils
    
      nano ~/.bashrc
    
      # add the following
      export EDITOR='nano'
      export VISUAL='nano'
      export NNN_USE_EDITOR=1
    

  • Remap right alt key with context menu button (I miss the context button on my ThinkPad)

      // add this to your startup script to make it permanent
      xmodmap -e "keycode  108 = Menu"
    

  • wordpress: fix file permission issues

      sudo find . -type f -exec chmod 644 {} \;
      sudo find . -type d -exec chmod 755 {} \;
      sudo chown -R www-data:www-data .
    

  • awk

      awk '/regex/'
      awk '!/regex/'
    
      awk 'BEGIN{a=5; b=2.5; print a+b}'
      awk '{sub(/:/, "-")} 1' // substitution
      awk '{gsub(/:/, "-")} 1'
    

  • Rename files in bulk using regex

      for f in *.ttf; do mv "$f" "$(echo "$f" | sed s/findthis/replacewiththis/)"; done
    

  • Make VS Code remember Github credentials; Easier if you are working with multiple accounts for work and personal.

      git config credential.helper store
    

  • Print exit code of previous-run program

      echo $?
    

  • if dpkg breaks while updating

      sudo dpkg --configure -a
      sudo apt --fix-broken install
    

  • to force remove a package

      sudo dpkg -P --force-depends <pkg-name>
    

  • copy from terminal to clipboard

      sudo apt install xsel
      echo "Hello" | xsel -ib
    

  • share files between devices on same network

      python3 -m  http.server
    

  • open editor to edit a command

      Ctrl+X Ctrl+E
    

  • get your IP

      curl ifconfig.me
    

  • raspberry pi - resolve wifi issue

      sudo killall wpa_supplicant
      sudo wpa_supplicant -c/boot/octopi-wpa-supplicant.txt -iwlan0
    

    if that doesn’t work

      sudo nano etc/wpa_supplicant/wpa_supplicant.conf
    
      	country=CA
    
      	ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
      	update_config=1
    
      	network={
      		ssid="**SSID**"
      		psk="**PASS**"
      	}
    
      sudo nano /etc/network/interfaces
    
      auto lo
      iface lo inet loopback
    
      iface eth0 inet manual
    
      auto wlan0
      allow-hotplug wlan0
      iface wlan0 inet manual
      	wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf
    
      sudo systemctl enable wpa_supplicant.service
    

    Thats it, reboot.

  • Play noise

    • pinknoise

        play -t sl -r48000 -c2 -n synth -1 pinknoise .1 60
      

    • whitenoise

        play -n synth 00:00:05 whitenoise
      

    • brownnoise as ocean waves

        play -n synth brownnoise synth pinknoise mix synth sine amod 0.3 10
      

• Android

  • unlock bootloader

      fastboot devices
      fastboot oem unlock
      fastboot flash recovery twrp.img
      fastboot reboot
    

• Windows

  • Flush DNS

      ipconfig /flushdns
      ipconfig /registerdns
      ipconfig /release
      ipconfig /renew
      netsh winsock reset
    

  • Power usage info

      powercfg -energy
    

  • PATH manipulation

      env | grep PATH
      echo $PATH
      export PATH=<previous-paths>:<new-path>
    

  • List network devices

      arp -a
    

  • Virtual Box issue on Windows 10 If you are not able to get Virtual Box in Windows, try running the following (as admin)

      dism.exe /Online /Disable-Feature:Microsoft-Hyper-V
    
      bcdedit /set hypervisorlaunchtype off
    

    Also make sure to remove the following from Windows Program and Features:

      * Hyper-V
      * Virtualizing Platform
    

  • Restart to UEFI settings

      shutdown -o -r -t 0
    

  • Restart graphics driver

      ctrl + shift + win + b
    

• nodejs

  • Installing NPM

      curl -L https://npmjs.org/install.sh | sudo sh
    

  • Clear node modules cache and install dependencies

      rm node_modules -r
      npm cache clean --force
      npm cache verify
      npm install
    

• common CLI

  • youtube-dl - best audio

      youtube-dl -f bestaudio --extract-audio --audio-format mp3 --audio-quality 0
    

  • termux - setting up, etc

    • settings file ~/.termux/termux.properties

    • add extra touch keyboard buttons

        extra-keys = [ \
        	['ESC','|','/','HOME','UP','END','PGUP','DEL'], \
        	['TAB','CTRL','ALT','LEFT','DOWN','RIGHT','PGDN','BKSP'] \
        ]
      

    • reload settings

        termux-reload-settings