[ILUG] Symbolic Linking

[Brian Foster]

  | Date: Thu, 03 Jan 2008 10:39:19 +0000
  | From: Frank Murphy <frankly3d.weblists at gmail.com>
  | 
  | If I need  libstdc++.so.5
  | and I have:
  |  /usr/lib/libstdc++.so.6
  |  /usr/lib/libstdc++.so.6.0.8
  | 
  | to symlink is it
  |  $ ln -s /usr/lib/libstdc++.so.6  /usr/lib/libstdc++.so.5
  | or
  |  $ ln -s /usr/lib/libstdc++.so.5  /usr/lib/libstdc++.so.6

 the way to remember which why it goes is
 to realise cp(1), mv(1), and ln(1) all
 have the same basic syntax:

   cmd  EXISTING_FILENAME  NEW_FILENAME

 so yer first form is the bunny (but see below!).
  and in this case, if you get it wrong (i.e.,
 backwards), all you'll get is an error:

   $ ln -s NEW_FILENAME EXISTING_FILENAME  # wrong!
   ln: `EXISTING_FILENAME': File exists

 no files are harmed.
 ( things are slightly trickier if you get
  it backwards and the last argument is a
  an existing directory --- but that's not
  yer case, so lets not go there .... )

 *BUT*... I rather doubt pretending v6 of
 libstdc++ is v5 will work.  yer kiloage
 will vary, but I suspect yer better off
 downloading the real v5.

  | [... should ] the higest version of the file
  | be used ala: /usr/lib/libstdc++.so.6.0.8 ?

 I suspect that if you look more closely,
 you'll find the .6 file is a symlink to
 the .6.0.8 file; that is, typically, the
 v<M> file is a symlink to the “highest”
 specific v<M.m.u> file (possibly via
 some other symlinks, such as v<M.m>).

cheers!
	-blf-
-- 
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