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Creating Symbolic Links

Symbolic links were created to overcome the two disadvantages of hard links: Hard links cannot span physical devices and hard links cannot reference directories, only files. Sym- bolic links are a special type of file that contains a text pointer to the target file or direc- tory.

Creating symbolic links is similar to creating hard links:

[me@linuxbox playground]$ ln -s fun fun-sym [me@linuxbox playground]$ ln -s ../fun dir1/fun-sym [me@linuxbox playground]$ ln -s ../fun dir2/fun-sym

[me@linuxbox playground]$ ln -s fun fun-sym [me@linuxbox playground]$ ln -s ../fun dir1/fun-sym [me@linuxbox playground]$ ln -s ../fun dir2/fun-sym

The first example is pretty straightforward, we simply add the “-s” option to create a symbolic link rather than a hard link. But what about the next two? Remember, when we create a symbolic link, we are creating a text description of where the target file is rela - tive to the symbolic link. It's easier to see if we look at the ls output:

[me@linuxbox playground]$ ls -l dir1

[me@linuxbox playground]$ ls -l dir1

The listing for fun-sym in dir1 shows that it is a symbolic link by the leading “l” in the first field and that it points to “../fun”, which is correct. Relative to the location of fun-sym, fun is in the directory above it. Notice too, that the length of the symbolic link file is 6, the number of characters in the string “../fun” rather than the length of the file to which it is pointing.

When creating symbolic links, you can either use absolute pathnames:

[me@linuxbox playground]$ ln -s /home/me/playground/fun dir1/fun-sym

[me@linuxbox playground]$ ln -s /home/me/playground/fun dir1/fun-sym

or relative pathnames, as we did in our earlier example. In most cases, using relative pathnames is more desirable because it allows a directory tree containing symbolic links and their referenced files to be renamed and/or moved without breaking the links.

In addition to regular files, symbolic links can also reference directories:

[me@linuxbox playground]$ ln -s dir1 dir1-sym

[me@linuxbox playground]$ ls -l

total 16

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