Linux Notes

Menu

• shell
• raspberry pi
• apt
• X11

shell

bash

• remove double quotes.
  • all "${opt//\"}"
  • suffix "${opt%\"}"
  • prefix "${opt#\"}"

zsh

• Prompt only displays the basename of the current directory.
  Change %~ to %1~
  Reference

raspberry pi

• headless wifi
  wpa_supplicant.conf

   country=US
   ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
   update_config=1
  
   network={
       ssid="your_real_wifi_ssid"
       scan_ssid=1
       psk="your_real_password"
       key_mgmt=WPA-PSK
   }
  

• headless ip address setup
  add a line in cmdline.txt
  ip=192.168.0.10

apt

• sudo dpkg -i –force-overwrite /var/cache/apt/archives/apport_2.20.1-0ubuntu2.4_all.deb

X11

Solution for Warning: No xauth data; using fake authentication data for X11 forwarding.

• at local(client) machine.

    touch ~/.Xauthority
    xauth generate $DISPLAY .
  

Issues

• Local sites running in WSL2 not accessible in browser
  • the windows docker edits the host file. it works well after reseting the host file.

    asdf with brew

• echo -e "\n. $(brew --prefix asdf)/libexec/asdf.sh" >> ${ZDOTDIR:-~}/.myshell.sh
• failed to use asdf zsh plugin

Emacs

The emacs daemon can be started automatically in a very simple manner. export ALTERNATE_EDITOR=""

ulimit -n in WSL2:

problem: https://askubuntu.com/a/1327539 walkaround: https://github.com/microsoft/WSL/discussions/6226

sudo

• How to make sudo preserve $PATH?