usermod: user weihao is currently used by process 4038

This error message indicates that the user "weihao" is currently running a process (identified by process ID 4038) that is preventing the user from being modified using the usermod command.

To modify the user "weihao", you will need to stop the process that is currently using that user account. You can do this by identifying the process using the "ps" command and then stopping it using the "kill" command.

For example, you can run the following commands to identify and stop the process:

1. Use the "ps" command to list all processes running under the user "weihao":

ps -u weihao

2. Identify the process ID (PID) of the process that is using the user "weihao".

3. Use the "kill" command to stop the process by specifying the PID:

kill PID

Once the process has been stopped, you should be able to modify the user "weihao" using the usermod command without encountering the error message.