A hard link is file system entry that associates a name with another file on a file system.

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How to diff two folders by inodes

I'm currently using a script to backup files on my computer. In a nutshell, it works like this: rsync --link-dest=$FOLDER/current $SOURCE $DESTINATION However, I think that my script may be ...
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1answer
92 views

hardlinks seem to take several hundred bytes just for the link itself (not file data)

Additional Info Firstly, thank you for all the answers. So I re-ran the tests again to test the answer below that a directory/folder entry takes up 4KB and this was skewing my numbers, so this time ...
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2answers
107 views

Several hard-links with different metadata in Linux using Ext4

Is it possible for Ext4 file systems (or maybe another one understood by Linux) to assign different metadata (like modification time, owner, access rights) to several hard-links that refer to the same ...
3
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1answer
296 views

How can I delete a hardlink to a directory?

Before I get 100s of answers that tell me it is impossible to hardlink directories in linux: yes, I know that. The file in question appeared in lost+fount after I checked the filesystem with e2fsck (...
3
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1answer
52 views

Deleting hardlink with rm -rfv deletes the original?

I was reading up on similar questions on here about what happens when you delete a hardlink to a file and the majority of the answers I was getting were that the hardlink is deleted but the original ...
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1answer
578 views

rsync's --link-dest option does not link because of file time

Consider this test case: mkdir a echo 'blah' > a/test mkdir b echo 'blah' > b/test rsync -r --link-dest=/tmp/b /tmp/a/ /tmp/c As expected, rsync creates c/test a hardlink of b/test (note the ...
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1answer
337 views

setgid binary doesn't have permission, mount's right, I'm missing something, but what, please?

I'm sorry, I know this has to be something simple but I've checked the manpages, the mount, the permissions ... (edit: combined history into one sequence as requested. Starting to seem a not-simple ...
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1answer
127 views

Files have the same inode but they don't link to each other

I have a bash script in two places and I can't remember how I created them. they have the same inode but none of them seem to link to another. is there a hard link but should not Links count for that ...
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3answers
672 views

Forcibly create directory hard link(s)?

I understand the reasoning why nearly every unix version doesn't allow hard-linking of directories (in fact HFS+ on OS X is the only one I know, but even that isn't made easy to do yourself). However, ...
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1answer
66 views

Why can't a UID 0 process hardlink to SUID files in a user namespace?

Consider the following transcript of a user-namespaced shell running with root privileges (UID 0 within the namespace, unprivileged outside): # cat /proc/$$/status | grep CapEff CapEff: ...
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656 views

Multiple Linux or Unix Distributions, Same Home Partition or Data?

To avoid conflicts I have always installed multiple Linux and Unix distributions each with it's own home partion or directory, and in the era of 3TB hard drives this is often very practical; I also do ...
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3answers
2k views

hardlink/softlink multiple file to one file

I have many files in a folder. I want to concatenate all these files to a single file. For example cat * > final_file; But this will increase disk space and also will consume time. Is there is a way ...
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2answers
813 views

Is a -rw-rw-rw- file really inaccessible inside a drwxrwx— directory?

Say I have a directory with these permissions: drwxrwx--- Inside this directory, a file with these permissions: -rw-rw-rw- Is the file readable/writable by everyone or not ? If not, how secure ...
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4answers
56 views

How to delete all duplicate hardlinks to a file?

I've got a directory tree created by rsnapshot, which contains multiple snapshots of the same directory structure with all identical files replaced by hardlinks. I would like to delete all those ...
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3answers
706 views

Convert a hardlink into a symbolic link

It is easy to convert a symlink into a hardlink with ln -f (example) It would also be easy to convert a hardlink (filenames link and original) back to a symbolic link to link->original in the case ...
2
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1answer
42 views

Editing a file with several hard links

Let's say I have two hard links pointing at the same picture. /photography/picture_1.jpg /best_pictures/picture_1.jpg What happens if I edit /photography/picture_1.jpg? Is the hard link broken and ...
2
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2answers
43 views

link to an executable and remove some parameters

I currently am using Xamarin Studio, which has a bug in this version. It adds 2 parameters to an executable, which causes the output to flood with error messages, slowing down the build time from a ...
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2answers
165 views

Hard-link creation - Permissions?

Which permissions affect hard-link creation? Does file ownership itself matters? Suppose user alice wants to create a hard-link to the file target.txt in a directory target-dir. Which permissions ...
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1answer
73 views

Can a hard link break the file system structure?

I want a very simple example of how can a hard link break the file system structure. I saw somewhere that people say it's because of loops, however, I can make a loop with a soft link and so I still ...
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1answer
1k views

How to safely remove hard-link to home folder?

In a folder owned by my user /sites/Website there is a dir named ~. When I cd to this directory, I am redirected to ~/, my home folder. At first I thought this was a symbolic link, but doing ls -...
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2answers
63 views

What is the best way to unlink hard-linked files?

Using rdfind I found a lot of hard-linked files (~60-90) and I want to unlink all of them. One possible solution is to just find all files -link +1 and just copy them, delete them and move it back to ...
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2answers
83 views

Can files with different inum be hard linked?

I am a new Linux user learning from Arch Linux and recently Linux From Scratch (7.7). I set up a new installation of AL to be my LFS host; I manually (and also with the provided bash script) checked ...
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1answer
934 views

Hard Linking Other Users' Files

Suppose User A and User B have disk quotas of 1 GB. Also suppose User B creates a 900 MB file with permission 0666. This allows User A to access that file temporarily (for some project, etc.). Notice ...
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24 views

Creating an Arch ISO image produces invalid cross-device link errors

I have been trying to create a custom Arch ISO by following the archiso article at The ArchWiki, unfortunately whenever I run ./build.sh -v from my ~/archlive directory I get one of two types of error....
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38 views

Space efficiency of Btrfs reflinks vs hardlinks

A webpage referenced by the Wikipedia article on Btrfs claims that (emphasis mine) [Btrfs] reflinks have the same use as hardlinks, but are more space efficient. I thought that the opposite was ...
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1answer
82 views

Generate SFV file, optimizing hard links

I'm currently running cfv -C -rr to generate a SFV file that contains the CRC32 checksums of all files in all subdirectories. The issue is that because there are so many hardlinks, this process is ...
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274 views

Directory symlink to inode, not path (e.g. directory hardlinks)

I'm trying to better understand why directory hardlinks are not possible. Roughly, I think of directories and files as follows: directory --------- inode # exposed as . inode_of_parent # ...
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2answers
137 views

Use the same file link for both Linux and Windows

As in the title, is it even possible to do so? I mean, can I create a link on Linux and than make this link valid also on Windows? Use-case I have the folder /media/Data/DownloadedMusic on a NTFS ...
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0answers
100 views

Hard links vs. Soft links: When would you want to use one over the other? [duplicate]

Possible Duplicate: What is the difference between symbolic and hard links? Today, my teacher talked about the differences between 'hard links' and 'soft links', but she never really explained ...
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3answers
604 views

Seemingly Inconsistent Behavior for “ln” & “ln -s”

As we all know, the ln command creates a link, with the default being a hard link and the -s option creating a symlink. The general syntax is ln [-s] OLD NEW, where OLD is the file you are linking to ...
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1answer
48 views

Extract hard link files with tar

I am trying to get list of all files in tar folder show them all on a page with links to download files. On click on single files it will be downloaded. This all is working fine except the hard link ...
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2answers
111 views

Two hard linked files share inode

I'm working on an assignment for my college course, and one of the questions asks for the command used to create a hard link from one file to another so that they point to the same inode. We were ...
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1answer
2k views

How do I manually modify an inode?

I am using Ubuntu Linux and, just for fun, I want to create a hardlink to a directory (as seen here). Because I'm just doing this for fun, I'm not looking for any sort of pre-developed directory-...
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2answers
2k views

How to find out a file is hard link or symlink? [duplicate]

I have a file in ~/file.txt. I have created a hard link by : ln ~/file.txt ~/test/hardfile.txt and a symlink file : ln -s ~/file.txt ~/test/symfile.txt Now, How can I find out that which file ...
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2answers
31 views

How are hard links counted in UNIX? [duplicate]

When we create a directory in UNIX it has 2 hard links: . and ... One to itself and another one to its parent directory. As I read the . increases counter of the directory, and the .. increases hard ...
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1answer
54 views

Should I use hardlinks for my “sites-enabled” folder instead of softlinks?

Every article I find about web servers suggest creating a sites-available and sites-enabled directory within apache/nginx/etc. Then, using symbolic (soft) links, create a link from the available to ...
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1answer
64 views

Why does looking for hardlinks fail?

Here is how I find hard links located in /tmp: $ for file in /tmp/*; do if [ "$(stat -c %h -- "$file")" -gt 1 ]; then ls "$file" -l ; fi; done total 0 srwxrwxr-x 1 t t 0 Mar 20 23:01 debconf.socket ...
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4answers
380 views

thoroughly find all links (hard and symlinks, and any combination thereof) leading to a file/dir [duplicate]

I read "most" of the proposed questions, but I believe they all miss the complexity of the right answer. I want, only using "basic" commands (for maximum portability) (i.e., something that would work ...
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1answer
166 views

If I hardlink to a directory, will the contents be “preserved” as if I hard-linked to every file?

I've seen people on the internet talk about using hardlinks to force files to stay on disk as a backup, even if they're deleted in their original location. Would this work for a directory too? Why or ...
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2answers
55 views

find all hard linked files between two directories

How do I find if any files among two or more directories are hard linked? In other words, do any files under two or more directories refer to the same file? Similar to How to find all hard links to ...
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1answer
75 views

What link should i use for home- & owncloud-data?

the plan is to built a debian-based sever with owncloud for syncing addressbooks, calendars, files etc. and also access large video-files in the LAN via webdav from some kodi-clients (maybe also use ...
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119 views

FS permission scenario

How can I achieve this files & folders permissions scenario: Consider these folder: Folder A: 640 root apache /var/www/A/ Folder www: 640 root apache /var/www/ and this linux user: id user1: uid=...
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1answer
239 views

rsync hardlink attempt copies

I've tried setting up a script to hardlink my files to my box.com account (as it's a backup of my music library). As I want to run it automatically to sync my music across several devices, I wanted to ...
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1answer
2k views

Backing up hard links (rsync)?

My question begins with: Do I actually have hard links on my disk at all (except for "." and ".." of course)? I'm not sure how I would find that out? If no, the question is already answered. If yes, ...
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3answers
64 views

Sharing a project tree between environments

To save space and time I copied a large project tree on a network drive as hard links, i.e. cp -a -r --link proj proj_B (background: it's huge, needs to be rebuilt from two incompatible ...
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1answer
76 views

is there some kind of symbolic links that support moving or renaming the target file?

I liked this explanation of hard and soft/symbolic links: http://unix.stackexchange.com/a/22406/42226 Now the reason why I googled about soft and hard links is simply because I was organizing my ...
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1answer
197 views

How to get a list all the “aliases” of a file (including of type directory) efficiently?

How can one get the list of all the aliases of a file (including of type directory) efficiently, given that a file: may have multiple hard links, multipe soft links, multi-level soft links may be ...
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1answer
87 views

What operations raise link count

I had an interview, where the interviewer asked what operations raise the link count of a file, besides ln and its underlying syscall, I didn't know. He stated that opening a file will increase the ...
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1answer
280 views

Linux command to copy as hard links, while deleting unwanted files?

I'm looking for a command that behaves both like cp -al in only creating hard links rather than copying file contents, and rsync -a --delete in removing files from the destination that are not ...
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22 views

What means a number of links > 1 for directories? [duplicate]

Both programs stat and ls -l tell about the number of (hard) links to file(s). Going under the assumption that one usually cannot create hardlinks for directories in Linux it confuses me to see ...