242

I have directory that contains some symbolic links:

user@host:include$ find .. -type l -ls
4737414    0 lrwxrwxrwx   1 user group       13 Dec  9 13:47 ../k0607-lsi6/camac -> ../../include
4737415    0 lrwxrwxrwx   1 user group       14 Dec  9 13:49 ../k0607-lsi6/linux -> ../../../linux
4737417    0 lrwxrwxrwx   1 user group       12 Dec  9 13:57 ../k0607-lsi6/dfc -> ../../../dfc
4737419    0 lrwxrwxrwx   1 user group       17 Dec  9 13:57 ../k0607-lsi6/dfcommon -> ../../../dfcommon
4737420    0 lrwxrwxrwx   1 user group       19 Dec  9 13:57 ../k0607-lsi6/dfcommonxx -> ../../../dfcommonxx
4737421    0 lrwxrwxrwx   1 user group       17 Dec  9 13:57 ../k0607-lsi6/dfcompat -> ../../../dfcompat

I need to copy them to the current directory. The resulting links should be independent from their prototypes and lead directly to their target objects.

  • cp -s creates links to links that is not appropriate behavior.
  • cp -s -L refuses to copy links to directories
  • cp -s -L -r refuses to copy relative links to non-working directory

What should I do?

Oliver Salzburg
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Basilevs
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10 Answers10

274
cp --preserve=links

From the man page:

   --preserve[=ATTR_LIST]
          preserve  the   specified   attributes   (default:   mode,owner-
          ship,timestamps),  if  possible  additional attributes: context,
          links, xattr, all

Personally, I use cp -av for most of my heavy copying. That way, I can preserve everything - even recursively - and see the output. Of course, that is just personal preference.

As to why your other options did not do what you expected, -s makes a link instead of copying and -L follows the links in the source to find the file to copy instead of copying the links themselves.

Gareth
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kainosnous
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85

Just as the man page says, use -P. This setting says:

-P, --no-dereference
       never follow symbolic links in SOURCE
mlissner
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Ignacio Vazquez-Abrams
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35

If the links contain relative paths, then, copying the link will not adjust the relative path. Use readlink, with the switch -f to follow recursively, in order to get the absolute path of the link. For example:

ln -s $(readlink -f old/dir/oldlink) new/dir/newlink

If preserving the relative paths is what you want, than the option -P of cp, as said by Ignacio Vazquez-Abrams, is what you need.

mrucci
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34

As a few have commented:

cp -a

works well.

From the man:

-a    same as -dR --preserve=all

-R    copy directories recursively
-d    same as --no-dereference --preserve=links
--no-dereference   never follow symbolic links in SOURCE
Juh_
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14

Most of the time, when I need to copy many symbolic links, I'm actually trying to mirror a directory tree. So I want the symlinks and everything else.

This is overkill for copying just a few symlinks, but if you're actually trying to copy an entire tree, this can be very useful:

Use tar.

user@host:/cwd$ ( cd /path/to/src ; tar cf - . ) | ( cd /path/to/dest ; tar xf - )

tar doesn't resolve the symlink by default, so symlinks in the mirror copy will point to the same locations as those in the original tree.

This trick makes use of subshells to get the tar command into position at the root of the directory to be mirrored; you can leave one of them out (along with the associated cd command) if you're already in the src or dest directories:

# already in src?
user@host:/src$ tar cf - . | ( cd /path/to/dest ; tar xf - )

# already in dest?
user@host:/dest$ ( cd /path/to/src ; tar cf - . ) | tar xf - 

# just need src/foo?
# this result will be a mirror copy at dest/foo 
user@host:/src$ tar cf - foo | ( cd /path/to/dest ; tar xf - )

# mirror to another system?
user@host:/src$ tar cf - . | ssh user@example.com '( cd /path/to/dest ; tar xf - )'

Again, this isn't appropriate for every time you want to copy symbolic links, but it is a very useful snippet to know.

quack quixote
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12

I used the following to duplicate a really large directory. All symbolic links were preserved, the copy was done recursively and I was able to have some visual feedback of the process:

cp -Prv /sourcer_dir/* /target_dir
oarevalo
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5

Use -P option, as Ignacio Vazquez-Abrams wrote above. What he didn't mention is -P has no effect without -R. So you need at least cp -RP.

(The site doesn't let me to comment yet so I posted a separate answer.)

1234ru
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4

Try: cp -pr symlink destination

[root@station1 temp]# ls -l
total 8
-rw-r--r-- 1 root root  0 Jul 27 18:40 abc
lrwxrwxrwx 1 root root 13 Jul 27 18:41 abc.link1 -> /tmp/temp/abc
[root@station1 temp]# cp -rp /tmp/temp/abc.link1 /tmp/temp/abc.link2
[root@station1 temp]# ls -l
total 12
-rw-r--r-- 1 root root  0 Jul 27 18:40 abc
lrwxrwxrwx 1 root root 13 Jul 27 18:41 abc.link1 -> /tmp/temp/abc
lrwxrwxrwx 1 root root 13 Jul 27 18:42 abc.link2 -> /tmp/temp/abc
[root@station1 temp]#

OS - Centos 5 (Linux)

ebe0
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3

On Ubuntu when copying links and files in a directory:

cp --no-dereference --preserve=links
Greg
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1

cp -s and cp -L are special commands. For your requirement, use none.

e.g. Copying a directory DIR containing a and a symbolic link b pointing to a.

  • cp -s DIR/* N/ creates a symbolic link instead of copying, N/a->../DIR/a (link) and N/b->(../DIR/b) which is link to a link
  • cp -L DIR/* N/ copies with link dereferencing, N/a, N/b (same as DIR/a)

What you need is N/a(=DIR/a), and N/b->../N/a; so just copy without dereferencing, using cp -P option. I believe this is also the default for cp.

  • -P no-dereference, preserve links
  • -d combines -P option with -p to preserve=mode,ownership,timestamps
  • -a combines -d option with -R to recursively copy directories

refer man cp or cp --help for more options.

Atif Hussain
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