UNIX File Types

Indicator in ls(1) Get file descriptor Create on file system
Regular File - open(2) open(2)
Directory d open(2) mkdir(2)
Symbolic Link l - 1) symlink(2)
Block or Character Device b or c open(2) mknod(2)
Pipe p open(2), pipe(2) mknod(2) or mkfifo(2) 2)
Socket s socket(2), accept(2), socketpair(2) bind(2)
1)
Linux does supports open(2) symbolic links by specifying flags O_NOFOLLOW and O_PATH, since version 2.6.39
2)
Some kernels having mkfifo(2) system call to create named pipes, thus mknod(2) can't be used