[EN] Linux Tips

Linux Tips

Ubuntu Development environment build commands

Disable Windows ENV:PATH

 
sudo su
echo -e  "[interop] \nappendWindowsPath=false">>/etc/wsl.conf

Necessary software pack

 
sudo apt update
sudo apt install cmake
sudo apt install build-essential
 

Bypass DNS Host Parse

Why? Bypass DNS server parse to avoid domain name pollution by GFW in China.

Find IP of Hostname by DNS lookup

 
nano /etc/hosts
# Format: XXX.XXX.XXX.XXX example.com

Use Windows Proxy

https://zhuanlan.zhihu.com/p/153124468
Get DNS Server IP, which point to windows
Apply only once

 
cat /etc/resolv.conf
export ALL_PROXY="<DNS Server IP Address>"

Persistence the proxy

 
sudo su
echo "host_ip=\$(cat /etc/resolv.conf | grep nameserver | cut -f 2 -d \" \")">>/etc/profile
echo "export ALL_PROXY=\"<Protocol>://\$host_ip:<your proxy port>\"">>/etc/profile
source /etc/profile
 

Install Homebrew

Install and config Oh-my-posh

Install LLVM

 
wget https://apt.llvm.org/llvm.sh
chmod +x llvm.sh
sudo ./llvm.sh <version number> all
 

WSL Commands

 
wsl --install
wsl --list --online
wsl --shutdown
wsl --mount <DiskPath>
wsl --unmount <DiskPath>
 

Environement Variables

https://blog.csdn.net/xjjxjy_2021/article/details/130875975

Common Environement Variables

PATH: Search path of commands.
HOME
LOGNAME
HOSTNAME
SHELL

Usage in Shell

Print environment variable values
echo $<env var name>
Example: echo $PATH

Set a new environment variable
Example:

 
export a_env_var="A Environment Variable"
env | grep a_env_var

Unset a environment variable
Example:

 
unset a_env_var
env | grep a_env_var

Add/Delete a item for $PATH

 
# Add
export PATH=$PATH:<path>

# Delete
echo $PATH # Copy without the path that ready to delete
export PATH=<paths>
 

Persistence environment varibale

 
sudo su
echo "export PATH=\$PATH:<path>">>/etc/profile
source /etc/profile
 

Proxy

Set DNS Server

 
nano /etc/resolv.conf

# Add nameserver below (Google DNS Server)
nameserver 8.8.8.8
nameserver 8.8.4.4

source /etc/resolv.conf

Set proxy alias

 
sudo su
echo -e "\nalias setproxy=\"export ALL_PROXY=socks5://198.18.0.1:16001 && echo \${ALL_PROXY}\"\n">>~/.bashrc
echo -e "\nalias unsetproxy=\"unset ALL_PROXY && echo 'proxy unseted.'\"\n">>~/.bashrc
source ~/.bashrc
 

Commands

update-alternatives

Switch the software version by update-alternatives
https://blog.csdn.net/qq_21367897/article/details/89606953

Add a new alternatives group

 
update-alternatives --install <link> <name> <path> <priority>
# example: sudo update-alternatives --install /usr/bin/clang clang /usr/bin/clang-16 1

Switch the version of software

 
update-alternatives --config <name>
# example: sudo update-alternatives --config clang

Remove alternatives group link

 
update-alternatives --remove <name> <path>
# example: sudo update-alternatives --remove clang /usr/bin/clang-14

alias

Define alias

 
# Example: 
alias print_hello_world="echo 'Hello world!'"
print_hello_world # Output: Hello world!
 

Show alias
alias -p

Persistence alias by put command into shell configuration file

 
sudo su
echo -e "\n <Some commands>">>~/.bashrc
echo -e "\n <Some commands>">>~/.bashrc
source ~/.bashrc
 

source

The Linux source command is a shell command that reads and executes commands from a file in current shell environment. file is typically a shell script, but it can also be any text file containing a series of commands. source command is often used to set environment variables, define functions, and execute initialization scripts.

find

https://www.linuxcool.com/find

Usage: find [path...] [expression]

 
find / -name *.conf     # Find file by name
find /etc -size +1M     # Find file by size
find /home -user user   # Find file own to specific user 
find .                  # List all file, directory
 