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Re: Difference in ln/ln -s semantics
From: |
Eric Blake |
Subject: |
Re: Difference in ln/ln -s semantics |
Date: |
Mon, 02 Feb 2009 06:12:30 -0700 |
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Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.19) Gecko/20081209 Thunderbird/2.0.0.19 Mnenhy/0.7.5.666 |
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According to Jim Meyering on 2/2/2009 6:06 AM:
>>
>> For semantic differences between ln and ln -s see the examples section.
>
> Thanks. Either would be good.
> Would you like to adjust doc/coreutils.texi accordingly?
The coreutils.texi documentation is already lengthy:
| A "hard link" is another name for an existing file; the link and the
| original are indistinguishable. Technically speaking, they share the
| same inode, and the inode contains all the information about a
| file--indeed, it is not incorrect to say that the inode _is_ the file.
| On all existing implementations, you cannot make a hard link to a
| directory, and hard links cannot cross file system boundaries. (These
| restrictions are not mandated by POSIX, however.)
|
| "Symbolic links" ("symlinks" for short), on the other hand, are a
| special file type (which not all kernels support: System V release 3
| (and older) systems lack symlinks) in which the link file actually
| refers to a different file, by name. When most operations (opening,
| reading, writing, and so on) are passed the symbolic link file, the
| kernel automatically "dereferences" the link and operates on the target
| of the link. But some operations (e.g., removing) work on the link
| file itself, rather than on its target. *Note Symbolic Links:
| (libc)Symbolic Links.
[By the way, POSIX 2008 mandates symlinks on all systems; about the only
system worth porting to these days that still lacks symlink support is the
non-POSIX mingw]
> If you change the man page (aka --help output), bear in mind
> that is should stay concise. It does point to the complete
> documentation in the info pages after all.
The trick is coming up with a concise statement for the --help output
which might help here.
- --
Don't work too hard, make some time for fun as well!
Eric Blake address@hidden
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