Back-end encounter some problems

1. Permission denied appears

The reason: insufficient privileges
Solution: sudo chmod -R 777 / home / xxx

1. shell脚本报错：-bash: xxx: /bin/sh^M: bad interpreter: No such file or directory

[root@localhost test] apt-get install dos2unix
[root@localhost test] dos2unix test.sh   
dos2unix: converting file test.sh to UNIX format ...  

1. Solve Django run error Error: That port is already in use.

a. Open the terminal. Enter the command ps aux | grep -i manage

The following message appears:

b. Locate PID (process id, as shown in the box part) python manage.py runserver corresponding. Enter the command kill -9 4988
so that you can kill off the process, release the port number (free up port 8000). If a plurality of repeated operations.