Fix “Permission denied” on Linux

Linux gives every file an owner plus read (r), write (w) and execute (x) permissions. The error appears when one of them is missing.

1. Read the file's permissions

   ls -l script.sh

   bashCopy

   The output looks like -rw-r--r-- 1 root root: no x, so it can't run, and root owns it.

2. Make a script executable

   chmod +x script.sh
   ./script.sh

   bashCopy

1. Take ownership of a file

   If root owns a file inside your home folder:

   sudo chown $USER:$USER script.sh

   bashCopy

2. Use sudo for system files

   Files in /etc or /usr need admin rights, for example sudo nano /etc/hosts.

Good to know : Never use chmod 777 to “fix” it: anyone could then modify the file.