How to create a symlink which opens (literally) the target file

Question

Suppose I have a file bar.txt inside directory foo and create a symlink baz.txt to foo/bar.txt. Like:

./foo
./foo/bar.txt
./baz.txt -> foo/bar.txt

If I open baz.txt my editor will think baz.txt is opened in directory .. Is there a way to create a link such that rather bar.txt is (literally) opened?

Context (or why I'm trying to do this): I have a directory with a large collection of files which I index and comment inside an .odt file which remains in the same directory. In this .odt file I create hyperlinks to the indexed files in the directory, so that I can easily access the individual files with (much) more context than just the filename. I set LibreOffice to save the hyperlinks as relative paths, so that these links will work in all of my computers, which not always have the same directory tree to my user files.

I'd like to create a symlink (or equivalent) to this .odt file, but (in the terms of the above example) if the link opens baz.txt then relative paths (from the point of view of LibreOffice) will be wrong. The formerly created hyperlinks will not work, and if I happen to create an hyperlink in baz.txt (figuratively, of course) it won't work in the original bar.txt.

Answer 1

No. But you can create a libreoffice wrapper that'll take each argument that is a symlink and turn it into $(readlink -f $the_symlink). You can then set your file manager to open libreoffice files through that wrapper.

lowrapper:

#!/bin/bash -e
args=()
for a; do
    case $a in 
        -*) args+=("$a");;  #skip flags (your file names don't start with -, right?)
        *)  if ! [ -L "$a" ]; then #not a link
                args+=("$a")
            else #link => target
                args+=( "$( readlink -f "$a")" )
            fi
            ;;
    esac
done
libreoffice "${args[@]}"

Now if you chmod +x lowrapper, put it in some directory of your PATH, and then change the handler program of your libreoffice files from libreoffice to lowrapper, then libreoffice will be opening the link targets instead of the links.

Answer 2

You can't, but what you can do instead is create symlinks to your "foo" directory like so:

./foo
./foo/root -> .
./root -> foo/.

Then append "root" to the start of all your hyperlinks. Now if you open your document from the ".", "root" will be resolved into "foo/.", and your "root/baz.txt" will resolve into "foo/./baz.txt". If opened from the "foo" itself, the same "root/baz.txt" will be resolved into "./baz.txt" because "root" points to ".".

Answer 3

I don't think there's any way to do exactly what you're asking for. Symlinks are file system constructs. However, there might be a decent workaround if you create a little script that opens the link target instead of the link:

#!/bin/bash

i=0
declare -a targets
for file in "$@"; do
        targets[$i]="$(readlink -f "$file")"
        ((i++))
done
libreoffice "${targets[@]}"

Save that in your PATH, for example as ~/bin/openLink.sh and make it executable:

chmod a+x ~/bin/openLink.sh`

Now, open your file manager (you mentioned caja), right click on an .odt file and choose "Open With" => "Other Application":

Click on the "Use a custom command" and put your script there:

Finally, close everything. Now, each time you click on an .odt file, it will be opened using that wrapper so it should open all links in their target directory. Note that readlink -f on a regular file just returns the name of the file, so this will also work for non-links.

Answer 4

I've ended up following a somewhat different approach, of creating a new file type -- let's call it "sim(ulated)link" -- which contains the (relative) path of file to be open, and then created a script do deal with it.

Consider the following scenario:

./dir1/dir11/foo.odt
./dir2/foo.odl

"odl" for "OpenDocument Link". The contents of "foo.odl" being:

../dir1/dir11/foo.odt

You can then create the following script to open *.odl (adapted from terdon's answer):

#!/bin/bash

declare -a targets
for file in "$@"; do
    targets+=( "$(readlink -f "$( dirname "$file" )"/"$( <"$file" )")" )
done
libreoffice "${targets[@]}"

(In case you don't want to use readlink because it will follow the link in case the path thus specified is a symlink, you could simply go with:)

#!/bin/bash

for file in "$@"; do
    cd "$( dirname "$file" )"
    libreoffice "$( <"$file" )"
done

You can then associate this script with .odl files in your file manager (as explained in terdon's answer). Eventually, you will have to create a mime type for .odl files and associate it with the script (lacking this step in my case worked, but associated all plain text files with the script, which was clearly undesirable).

Why have I preferred this alternative to the ones provided by PSkocik and terdon, even though they work perfectly fine? For three reasons:

• Not all of my .odt files (and links to them) have this structure that I have to open them "in the target file's directory". In this way, I affect the opening procedure only of the files of interest.

• The system regular symlinks will work regardless of the settings in my current computer. This means that, if I happen to open one of these files in a computer in which I didn't change the settings to open .odt files with my script, it will open anyway and I may inadvertently mess up with the paths of my hyperlinks within it. This way, if the computer is not setup to open .odl files, they simply won't work, and I will have to go for the target files directly.

• Lastly, in case I move or rename some of the directories involved, I can easily search and replace the .odl files to correct the paths. (This is likely also doable with the symlinks, but seems somewhat harder).

Caveats: I think this will only work for a well formed, non redundant, relative path given in the .odl file. There is probably a way to do things more robustly in the sense that it would work also with an absolute path or with a relative path with some redundancy in it.