[ILUG] hard- vs. soft-links [was: How to copy some files ]

[Brian Foster]

  | Date: Fri, 19 Jul 2002 18:10:40 +0100
  | From: Ronan Waide <waider at waider.ie>
  | 
  | On July 19, niall at linux.ie said:
  | > this case, [hard links] are being used to provide two quite
  | > different namespaces for the same set of files.
  | 
  | Sure, but soft links would do the same. To be honest, I'm trying to
  | think of a useful use of hard links right now, and I'm a little
  | stumped. There's gotta be some benefit that I'm missing that's
  | immediately obvious to everyone.

 maybe, maybe not.   yonks ago, I seem to recall dmr saying,
 or at least alleged to have said, something along the lines
 that soft and hard links both make sense in isolation, but
 having both does not.  if this is even close to correct,
 yer in quite good company!

 there is at least one notable difference, and a host of minor
 ones.  the notable difference is the data always exists (and
 is apriori accessible) for hard links --- there is no such
 thing as a broken link.

 I use this fact on occasion to "save" data, via the well-
 known attack of hard-linking to a supposedly-temporary file
 I want to preserve.  the subsequent unlink(2)ing of the
 "temporary" file does not destroy the data.
 
cheers!
	-blf-
--
 Innovative, very experienced, Unix and      | Brian Foster    Dublin, Ireland
 Chorus (embedded RTOS) kernel internals     | e-mail: blf at utvinternet.ie
 expert looking for a new position ...       | mobile: (+353 or 0)86 854 9268
  For a résumé, contact me, or see my website  http://www.blf.utvinternet.ie

    Stop E$$o (ExxonMobile):  «Whatever you do, don't buy Esso --- they
     don't give a damn about global warming.»    http://www.stopesso.com
     Supported by Greenpeace, Friends of the Earth, and numerous others...