You can think of everything in a Linux filesystem as a stream of bytes. This is simply called a file. A directory is also a file that contains other files. Most of the files are located on your computer's hard disk. However, some are in memory, for example, /proc
and /sys
are actually virtual filesystems. Files can also be stored on removable media too such as USB devices, CD/DVDs, and on other machines (that is, NFS mounts).
Every file under a filesystem has a special number called an inode. The inode is where the OS stores the properties of the file and contains the following information:
The file type such as regular, directory, special, link, socket, pipe, or block device
The owner and group information
The permissions of the file (more on this in Chapter 5, Permissions, Access, and Security)
Date and time on which the file was created and when last changed or read
The file size
The inode contains some other information as well
Things that...