Now that we have a basic understanding of how filesystems work, we’ll turn our attention to understanding how filesystems influence the security of a Unix system. Nearly all of this discussion will be concerned with the metadata that a filesystem contains—the filenames, permissions, timestamps, and access control attributes.
You can use the ls command to list all of the files in a directory. For instance, to list all the files in your current directory, type:
lsinstructions invoice letter more-stuff notes stats %
Actually, ls alone won’t list all of the files. Files and directories beginning with a dot (“.”) are hidden from the ls command but are shown if you use ls -a:
ls -a. .. .indent instructions invoice letter notes more-stuff stats %
The entries for “.” and “..” refer to the current directory and its parent directory, respectively. The file .indent is a hidden file. If you use ls -A instead of ls -a, you’ll see hidden files, but “.” and “..” will not be shown.
You can get a more detailed listing by using the ls -lF command:
ls -lFtotal 161 -rw-r--r-- 1 sian user 505 Feb 9 13:19 instructions -rw-r--r-- 1 sian user 3159 Feb 9 13:14 invoice -rw-r--r-- 1 sian user 6318 Feb 9 13:14 letter -rw------- 1 sian user 15897 Feb 9 13:20 more-stuff -rw-r----- 1 sian biochem 4320 Feb 9 13:20 notes -rwxr-xr-x 1 sian user 122880 Feb 9 13:26 stats* %
The first line of output generated by the ls
total 161 in the example ...