Special file types (GNU Coreutils 9.0)
12 Special file types
This chapter describes commands which create special types of files (and
rmdir, which removes directories, one special file type).
Although Unix-like operating systems have markedly fewer special file types than others, not everything can be treated only as the undifferentiated byte stream of normal files. For example, when a file is created or removed, the system must record this information, which it does in a directory—a special type of file. Although you can read directories as normal files, if you’re curious, in order for the system to do its job it must impose a structure, a certain order, on the bytes of the file. Thus it is a “special” type of file.
Besides directories, other special file types include named pipes (FIFOs), symbolic links, sockets, and so-called special files.
|• link invocation||Make a hard link via the link syscall|
|• ln invocation||Make links between files.|
|• mkdir invocation||Make directories.|
|• mkfifo invocation||Make FIFOs (named pipes).|
|• mknod invocation||Make block or character special files.|
|• readlink invocation||Print value of a symlink or canonical file name.|
|• rmdir invocation||Remove empty directories.|
|• unlink invocation||Remove files via the unlink syscall|