What is the difference between fs.link and fs.symlink? Are they platform independent?

Question

What is the difference between fs.link and fs.symlink?

I want to programmatically create a symbolic link to a physical file (or another symlink), and I'm on Linux, but wondered if it was possible to write a OS independant solution? What are the limitations?

Update

From the given answers and comments, Windows seems to support it.

Answer 1

Linux systems have two kinds of links, hard and soft.

fs.link() is creating hard links through the C system call link(). From a terminal the equivalent is ln originalName linkName. A hard link consists of a new directory entry referencing the same file. In listings it appears to be an ordinary file, just like the original file. If the original file is removed, the content is not removed, and the hard link still works. The area of the disk is only freed when all hard links are deleted.

fs.symlink() is creating soft links, a.k.a symbolic links through the C system call symlink(). From a terminal the equivalent is ln -s originalName linkName where the -s tag denotes a soft/symbolic link. A soft link creates a special kind of directory entry that points to another file. The fact that it is a pointer is obvious when listing it, and deleting the original is sufficient to delete the content, and disrupts using the link.

I don't code on MS Windows, but this guide on symbolic links indicates that there is a mklink command for Windows command shell that can create either a hard (mklink /H) or a soft (mklink /D) link. Microsoft Developer's Network -- MSDN -- has entries for system functions CreateSymbolicLink and CreateHardLink which may provide more information about what is happening at a lower level.

On Mac, developer.apple.com's page for ln shows they have the BSD version of the ln link creation terminal command in Mac OSX 10.9, supporting both hard and soft links.