Tilted Forum Project Discussion Community  

Go Back   Tilted Forum Project Discussion Community > Interests > Tilted Technology


 
 
LinkBack Thread Tools
Old 06-08-2004, 05:27 PM   #1 (permalink)
Upright
 
Not programming... not really computers...

Does anyone know why I cannot create a hard link to a directory with 'ln' on my linux box? The man page reads:

-d, -F, --directory
hard link directories (super-user only)

So su'ed to root, I shouldn't be getting this:

$ ln -d mail myMail
ln: creating hard link `myMail' to `mail': Operation not permitted
bogosj13 is offline  
Old 06-08-2004, 10:09 PM   #2 (permalink)
Junkie
 
Location: San Francisco
You mean, # ln -d mail myMail? =P
Hmm I'm not sure, is mail a symbolic link? (I don't actually know whether you're allowed to make hard links to symlinks, just a random guess.)

edit: don't think that's it
__________________
"Prohibition will work great injury to the cause of temperance. It is a species of intemperance within itself, for it goes beyond the bounds of reason in that it attempts to control a man's appetite by legislation, and makes a crime out of things that are not crimes. A Prohibition law strikes a blow at the very principles upon which our government was founded." --Abraham Lincoln

Last edited by n0nsensical; 06-08-2004 at 10:20 PM..
n0nsensical is offline  
Old 06-09-2004, 04:46 AM   #3 (permalink)
In Your Dreams
 
Latch's Avatar
 
Location: City of Lights
I assume they're on the same filesystem

what if you tried

$ ln -d mail/ myMail/ ?

or try just

$ ln mail myMail
(or)
$ ln mail/ myMail/


Do any of those combos work for you? I'm thinking the first and second would, but not sure.
Latch is offline  
Old 06-09-2004, 10:12 AM   #4 (permalink)
Wehret Den Anfängen!
 
Location: Ontario, Canada
Do you really want a hard link to a directory? Directory hard links are hard to make for a reason. I'd generally advise making a soft link unless you have a very specific reason to make a hard link.
__________________
Last edited by JHVH : 10-29-4004 BC at 09:00 PM. Reason: Time for a rest.
Yakk is offline  
Old 06-09-2004, 11:10 AM   #5 (permalink)
Über-Rookie
 
Location: No longer, D.C
Since you have already had answers about the hard link, may I ask the reasoning you are going against a symlink here?

I find that symlinking directories are often much easier.
__________________
"All that we can do is just survive.
.All that we can do to help ourselves is stay alive." - Rush
oblar is offline  
Old 06-09-2004, 11:31 AM   #6 (permalink)
Upright
 
I'm not doing this for any particular reason, just out of curiousity really. I generally don't like being told I can do something (in the man page) and then trying it and have it not work.

Yes, they are both on the same FS, actually they would be residing in the same directory if you take my command line exactly.

No, the original directory is not a symlink.

I guess it's more trying to figure out why this wouldn't work, or wouldn't be advisable. A directory is just a file with another bit set, is it not? Still held in an inode. Why is it OK to have a file that's hard linked, but not a directory then?

Edit: results of the above:
[root@mybox ~]# ln -d mail/ myMail/
ln: creating hard link `myMail/' to `mail/': No such file or directory

[root@mybox ~]# ln mail mymail
ln: `mail': hard link not allowed for directory

[root@mybox ~]# ln mail/ myMail/
ln: `mail/': hard link not allowed for directory

Last edited by bogosj13; 06-09-2004 at 11:34 AM..
bogosj13 is offline  
Old 06-09-2004, 11:53 AM   #7 (permalink)
Crazy
 
http://c2.com/cgi/wiki?HardLink

This link has information you might be interested in.
__________________
"Even if you prove me wrong, I'm not going to believe you." - A. McGill
firebirdta is offline  
Old 06-09-2004, 05:39 PM   #8 (permalink)
Darth Papa
 
ratbastid's Avatar
 
Location: Yonder
Quote:
Originally posted by bogosj13

[root@mybox ~]# ln -d mail/ myMail/
ln: creating hard link `myMail/' to `mail/': No such file or directory
Hey, it wanted to work that time!

One mistake I frequently make with ln is that I give the args in the wrong order. I forget that it's "from" and "to" like cp, I for some reason thing the syntax ought to be more like "link this new thing to that old thing". Could that have bitten you?
ratbastid is offline  
Old 06-10-2004, 05:00 AM   #9 (permalink)
In Your Dreams
 
Latch's Avatar
 
Location: City of Lights
Quote:
Originally posted by ratbastid
Hey, it wanted to work that time!

One mistake I frequently make with ln is that I give the args in the wrong order. I forget that it's "from" and "to" like cp, I for some reason thing the syntax ought to be more like "link this new thing to that old thing". Could that have bitten you?
Ahhh.. reversed args.. that makes sense.
Latch is offline  
Old 06-10-2004, 06:52 AM   #10 (permalink)
Wehret Den Anfängen!
 
Location: Ontario, Canada
Read firebirdta's link.

Making directory symlinks can break some filesystems. There is a reason only root can do it. Unless you have a very good reason to do it, understand precicely what the implications are on your particular filesystem, and are sufficiently skilled to do debugging on filesystem internal data structures, do not do it.

So, I'm a bit paranoid.
__________________
Last edited by JHVH : 10-29-4004 BC at 09:00 PM. Reason: Time for a rest.
Yakk is offline  
Old 06-10-2004, 02:46 PM   #11 (permalink)
Upright
 
Quote:
Originally posted by Latch
Ahhh.. reversed args.. that makes sense.
No, the args are definatly in the right order. That wiki link makes sense, especially:

Quote:
... Depending on the kernel, the decision to allow a directory hard link may be deferred to the filesystem module itself.
That makes sense why even as root I cannot do it.
bogosj13 is offline  
Old 06-11-2004, 02:54 PM   #12 (permalink)
pig
pigglet pigglet
 
pig's Avatar
 
Location: Locash
quick question....what happens if you try full path names to the directories? I've had that sort of thing come up as well...especially with that command that gave the "no such file or directory" jazz
__________________
You don't love me, you just love my piggy style
pig is offline  
Old 06-12-2004, 08:08 AM   #13 (permalink)
Upright
 
Doesn't seem to matter, take the three examples above, with full paths, they return the same error messages.
bogosj13 is offline  
 

Tags
computers, programming


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -8. The time now is 03:16 PM.

Tilted Forum Project

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
© 2002-2012 Tilted Forum Project

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40