Different Types of Unix files

There are mainly three types of Unix files. They are

◈ Regular files
◈ Directories
◈ Special or Device files

Regular Files

Regular files hold data and executable programs. Executable programs are the commands (ls) that you enter on the prompt. The data can be anything and there is no specific format enforced in the way the data is stored.

The regular files can be visualized as the leaves in the UNIX tree.

Directories

Directories are files that contain other files and sub-directories. Directories are used to organize the data by keeping closely related files in the same place. The directories are just like the folders in windows operating system.

The kernel alone can write the directory file. When a file is added to or deleted from this directory, the kernel makes an entry.

A directory file can be visualized as the branch of the UNIX tree.

Special Or Device Files

These files represent the physical devices. Files can also refer to computer hardware such as terminals and printers. These device files can also refer to tape and disk drives, CD-ROM players, modems, network interfaces, scanners, and any other piece of computer hardware. When a process writes to a special file, the data is sent to the physical device associated with it. Special files are not literally files, but are pointers that point to the device drivers located in the kernel. The protection applicable to files is also applicable to physical devices.