What does the permission string lrwxrwxrwx mean?

The leading l indicates that this file is a symlink, in contrast to - which indicates a regular file, d which indicates a directory, and other less common prefixes.

A symlink is type of file which only contains a link to another file. Reading a symlink reads the real file. Writing to a symlink writes to the real file. cding to a symlink that is to a directory results in behaviour almost identical to what would happen if you had cd'd into the real directory.

The permission bits are displayed as rwxrwxrwx. All symlinks show these bits, but they are "dummy permissions". The actual (or effective) permissions of a symlink are the permissions of the real file it links to. You can get the real permissions (and file type) by running stat on the symlink, for example:

$ stat -Lc '%a %A' /initrd.img
644 -rw-r--r--

• stat read file metadata
• -L dereference (follow) symlinks
• -c select output according to specified string
• %a octal permissions
• %A "human readable" permissions