What does this do?
ln -nsfI know ln -s creates a symbolic link, not a hard link which means you can delete it and it won't delete the think that it's linking to. But what do the other things mean? (-nf)
Update: okay...so I remembered you can find this stuff out from the command line. Here's what I found out from typing ln --help:
-f, --force remove existing destination files
-n, --no-dereference treat destination that is a symlink to a directory as if it were a normal fileBut this still isn't very clear to me what the implications of this are. Why would I want to create a soft/sym link like this?
36 Answers
From the BSD man page:
-f If the target file already exists, then unlink it so that the link may occur. (The -f option overrides any previous -i options.) -n If the target_file or target_dir is a symbolic link, do not follow it. This is most useful with the -f option, to replace a symlink which may point to a directory.the -n option (together with -f) forces ln to update a symbolic link to a directory. what does that mean?
suppose you have 2 directories
- foo
- bar
and an existing symbolic link
- baz -> bar
now you want to update baz to point to foo instead. if you just do
ln -sf foo bazyou would get
- baz/foo -> foo
- baz -> bar (unchanged), and thus
- bar/foo -> foo
if you add -n
ln -sfn foo bazyou get what you want.
- baz -> foo
that is what 'no-dereference' means: do not resolve an existing link and place the new link inside that directory, but rather just update it.
2Here are all the options to ln. You'll find -n and -f in here.
-F If the target file already exists and is a directory, then remove it so that the link may occur. The -F option should be used with either -f or -i options. If none is specified, -f is implied. The -F option is a no-op unless -s option is specified. -h If the target_file or target_dir is a symbolic link, do not follow it. This is most useful with the -f option, to replace a symlink which may point to a directory. -f If the target file already exists, then unlink it so that the link may occur. (The -f option overrides any previous -i options.) -i Cause ln to write a prompt to standard error if the target file exists. If the response from the standard input begins with the character `y' or `Y', then unlink the target file so that the link may occur. Otherwise, do not attempt the link. (The -i option overrides any previous -f options.) -n Same as -h, for compatibility with other ln implementations. -s Create a symbolic link. -v Cause ln to be verbose, showing files as they are processed.
You can type "man ln" to find such things:
-f, --force remove existing destination files -n, --no-dereference treat destination that is a symlink to a directory as if it were a normal file-f, --force remove existing destination files
-n, --no-dereference treat destination that is a symlink to a directory as if it were a normal file
-f says that if the target of your command is an existing file, it should be removed and replaced by the new link. (Note that in Unix-influenced systems, "file" can include directories, links, pipes, etc.)
-n modifies -f, saying that if the target you specify is an existing symbolic link, it should not be removed.
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