Display all entries in the current directory including those beginning with a period. Display a long or detailed listing of the current directory, one line of data for each entry. To get a list of all of the other options of ls, use the man command. The standard unix filesystem does this with permissions. Each file has read, write and execute permisssions set for the owner, the group and then all other users.
Users can create links to existing files.
The filesystem keeps track of the number of links. Unix is a multi-user operating system. For each file and directory, the filesystem keeps track of the file owner and group. The date that appears in a standard directory entry is the last modification date. Ordinary users cannot view the contents of some of these directories.