Fix Missing Username in Linux Terminal

If the Linux terminal does not display the username, it could be due to the following reasons:

1. If the username is set to hide: type the command echo $PS1 in the terminal, if the result does not include \u, then the username is hidden. You can modify the settings of the terminal prompt by editing the ~/.bashrc or ~/.bash_profile file.
2. Issue with terminal theme settings: Some terminal themes may hide the username. Try using a different terminal theme or modify the settings of the current theme.
3. Terminal font configuration issue: Some terminal fonts may not properly display usernames. Try changing the terminal font to one that supports displaying usernames.
4. The user did not successfully log in: If there was no successful login, the username will not be displayed on the terminal. Please make sure to enter the correct username and password.

If the above methods are not effective, it may be necessary to further investigate system configurations or try resetting the user environment.