How to change a symlink in OS X?

How do I change where a symlink points to, without deleting and creating a new one (with ln -s "/path/to/point/to" "/path/where/symlink/is")?

When I tried doing that to Java's "Current" symlink, Java wouldn't even work (from the command line, at least, said 'Segmentation Fault') but it was back to normal when I restored the old "Current" symlink with Time Machine (but later I found out I should use /Applications/Utilities/Java Preferences.app anyway to change current java version).

mk12

Posted 2009-09-06T12:58:09.120

Reputation: 2 432

Answers

mkdir /path/where/newsymlink
ln -s /path/to/point/to /path/where/newsymlink/is
mv /path/where/newsymlink/is /path/where/symlink/
rmdir /path/where/newsymlink

However, the Java Preferences utility changes more than just a symbolic link; you should use that to ensure that the Java version is changed.

mark4o

Posted 2009-09-06T12:58:09.120

Reputation: 4 729

wouldn't the mv command just rename it..? – mk12 – 2009-09-06T19:17:54.080

.. I tried that, it justs moves the new symlink into the folder that the old one points to. – mk12 – 2009-09-06T19:26:37.570

The first command makes the symlink that points where you want, and the second command replaces the existing pointer to the old place with the pointer to the new place. The mv is atomic so the symlink will always exist. – mark4o – 2009-09-07T00:00:55.660

.. But it still doesn't work.. it moves the new pointer into the folder that the old one points to. – mk12 – 2009-09-07T02:08:07.227

/path/where/symlink/is is the symlink that you are changing. Using these commands will change it to point to /path/to/point/to. The folder that the original symlink points to is not touched at all. – mark4o – 2009-09-07T07:20:43.283

The mv command doesn't make it replace the old one with the new one, it moves the new one into the old one (into the folder it points to). I tried several times. – mk12 – 2009-10-16T12:47:25.897

@Mk12: You're supposed to give the new one the same name as the old one. So it should overwrite it. – Sasha Chedygov – 2009-10-19T21:19:04.890

I did, but it doesn't. It moves it into the directory it points to. – mk12 – 2009-10-25T13:28:56.977

@Mk12: Sorry, you are right. I have fixed my answer to handle this, although it is now 4 commands instead of 2... :-( – mark4o – 2009-10-26T07:45:38.853

Those instructions are very hard to follow. – mk12 – 2009-10-28T20:07:27.537

It is just moving a new link over the old one. The mkdir/rmdir is just there because "mv x y" renames x to y/x instead of just y if y is a directory or a link to a directory. If mv had an option to suppress this behavior then it would be simpler. – mark4o – 2009-10-31T22:36:27.160

ln -hfs newlocation existinglink

ln -nfs newlocation existinglink

will change the existing link to point to newlocation

(the -n and -h are identical in operation)

From 'man ln'

-h If the target_file or target_dir is a symbolic link, do not follow it. This is most useful with the -f option, to replace a symlink which may point to a directory.

-f If the target file already exists, then unlink it so that the link may occur. (The -f option overrides any previous -i options.)

-s Creae a symbolic link

Maxxx

Posted 2009-09-06T12:58:09.120

Reputation: 401

The -nfs version works also on Linux, so it is more portable if anyone cares. – Cromax – 2019-12-15T23:03:35.780

Try:

unlink /path/to/current/link
ln -s /path/to/target /path/to/symbolic/link

mote

Posted 2009-09-06T12:58:09.120

Reputation: 236

1On my late 2013 MacBook Pro with Mavericks, I had to switch the two parameters: ln -s /path/to/symbolic/link /path/to/target – Marius Waldal – 2014-02-11T14:35:39.850

The ln command doesn't let you change links, only create new ones.

mk12

Posted 2009-09-06T12:58:09.120

Reputation: 2 432

Have you compared the permissions on the links and on the targets before and after you change the link? You might just need to follow up with the appropriate chown and chmod commands to get it working.

Josh

Posted 2009-09-06T12:58:09.120

Reputation: 348

Well I don't even know how to change it so no. And I don't know what chown and chmod do. – mk12 – 2009-09-06T13:22:14.923

2chown changes ownership of a file and/or directory. chmod changes permissions of a file and/or directory. These are standard in just about every unix platform. Too much detail to explain each here, so I would recommend googling each for tutorials. You can also do "man chown" or "man chmod" to read the actual manual of the command (hit q to get out of the manual). – churnd – 2009-09-06T13:56:20.937