Making a duplicate of a path in Unix

Question

My Unix vocabulary is failing me. I have 5 billion images in /foo/live/images.

For the purposes of developing a new version of the app I'd like to make /foo/dev/images into a working path without making a copy of the images.

Is this a soft link? What's the right term? What's the command-line syntax to create the link?

Mikaveli · Answer 1 · 2011-05-26 22:58:25Z

up vote 9 down vote

Dead simple, it's just a symbolic link:

ln -s /foo/live/images /foo/dev/images

Just watch the directory permissions etc. To view the man page (all available options) for the ln command, enter the following at the prompt:

man ln

answered May 26 '11 at 22:58

Mikaveli

Thank you very much! – jerrygarciuh May 27 '11 at 0:50

Seth Robertson · Answer 2 · 2011-05-26 22:59:46Z

up vote 5 down vote

You can use either symbolic links or hard links (for individual files) assuming they are on the same filesystem.

cd /foo/live; find images -type d -printf "mkdir -vp '/foo/dev/%p'\n" -o -type f -printf "ln -vs '/foo/live/%p' '/foo/dev/%p'\n" | sh

Whether you do this or cd /foo/dev; ln -s ../live/images . depends on whether you might write into the images directory.

answered May 26 '11 at 22:59

Seth Robertson
1662

	Hard links for "5 billion images" - really? Whilst you're answer is correct, I'd opt for a more canonical example for a *nix novice. – Mikaveli May 26 '11 at 23:14
	@Mikaveli: Sure, you are using a lot of inodes (symlinks) and directory entries/inodes (both), but for some applications/usage patterns you might not be able to use the directory symlink. We didn't get enough information to say which was needed so I provided the option. – Seth Robertson May 27 '11 at 0:15
	Thank you very much! – jerrygarciuh May 27 '11 at 0:50
	+1 for providing the alternative. :) – Mikaveli May 27 '11 at 8:18

migrated from stackoverflow.com May 31 '11 at 14:57