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41 lines
1.4 KiB
Plaintext
41 lines
1.4 KiB
Plaintext
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====== Hardlink ======
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Also the article for:
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* filename
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A hardlink associates a //filename// with a [[dict:terms:file | file]]. That name is an entry in a directory listing. Of course a file can have more hardlinks to it (usually the number of hardlinks to a file is limited), but all hardlinks to a file must reside on the same [[dict:terms:filesystem | filesystem]] as the file itself!
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What you usually call a file is just a name for that file, and thus, a hardlink.
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The difference between a [[dict:terms:symlink | symbolic link]] and a hard link is that there is no easy way to differentiate between a 'real' file and a hard link, let's take a look at the example:
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* create an empty file
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<code>$ touch a</code>
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* create a hard link 'b' and sym link 'c' to empty file
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<code>$ ln a b
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$ ln -s a c</code>
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as you can see file(1) can't differentiate between a real file 'a' and a hard link 'b', but it can tell 'c' is a sym link
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<code>$ file *
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a: empty
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b: empty
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c: symbolic link to `a'</code>
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''ls -i'' prints out the inode numbers of files, if two files have the same inode number AND are on the same file system it means they are **hardlinked**.
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<code>$ ls -i *
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5262 a 5262 b 5263 c</code>
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hard links don't consume additional space on the filesystem, the space is freed when the last hard link pointing to it is deleted.
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===== See also =====
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* [[dict:terms:file | file]]
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* [[dict:terms:filesystem | filesystem]]
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* [[dict:terms:symlink | symlink]]
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