Команды

chmod 755 <filename>



chmod +r <fileName> - право на чтение файла всем

chmod calculator

755 means read and execute access for everyone and also write access for the owner of the file. When you perform chmod 755 filename command you allow everyone to read and execute the file, owner is allowed to write to the file as well.

ls -l <имя файла> - даёт описание файла