Linux Files and Permissions

By the end of this lesson you can read an ls -l line, name the owner, group and "everyone else" classes, explain read, write and execute for files and for folders, convert a permission string to its three-digit number and back, and spot a permission that puts a file at risk. There is no lab in this lesson: every command is shown together with the exact result it prints, so you can read along and answer the questions without typing anything. The one change you see made is to a file the learner owns in their own home folder, and nothing else on the machine is touched.