Find all symbolic links pointing to a file

Not possible AFAIK. However, you could check out the manpage for ln and any that it points to.

If you want to install the GNU 'find' command, you could use:

find -L / -samefile /path/to/real_file

You can install the GNU 'find' command via <http://www.gnu.org/software/findutils/>, or fink.sf.net findutils, or MacPorts.org findutils.

Note, searching from the root directory / through all the files you have will take lots of time.

If you do not want to install the GNU 'find' command, here is a script that, while even slower than the 'find' command should also locate all symlinks that point to a specific file:

#!/usr/bin/env bash
if [[ $# != 2 ]]; then
 echo 1>&2 "Usage: ${0##*/} /starting_directory /path/to/reference_file"
 exit 1
fi
START="$1"
export REFFILE="$2"
find $START -type l | perl -ne '
 if ( ! $initialized ) {
 $initialized = 1;
 $reffile = $ENV{"REFFILE"};
 @ref = stat($reffile);
 }
 chomp;
 @st = stat($_);
 if ( $st[0] == $ref[0] && $st[1] == $ref[1] ) {
 print `ls -l "$_"`;
 }
'

Without having to install the GNU 'find' command, then from an admin-privileged login,

sudo -s
find / -type l -print0 | xargs -0 ls -TalkOs | sudo grep ' ->' | grep {filenameOfRealFile}

use just enough of the filename, to which any/all links point, to uniquely identify it. That is, I wouldn't include the filepath because, for example, links in the same directory won't display with the arrow followed by path.

As an example, on my computer I have a link in /etc/periodic/weekly that points to the real executable in /usr/local. When I type the above command to search for links, I get

iMac:jv imac$ sudo -s
Password:
iMac:jv root# find / -type l -print0 | xargs -0 ls -TalkOs | grep ' -> ' | grep diskPM
4 lrwxr-xr-x 1 root wheel - 17 Jul 12 21:42:30 2010 /private/etc/periodic/weekly/600.diskPM -> /usr/local/diskPM

the find -type l looks for links, the -print0 and xargs -0 handle white space in file names, and the two greps filter out everything but the real file name for which you are searching for its links.

Message was edited by: j.v.

....or, I guess you could run BobHarris' script.

Message was edited by: j.v.

OK, I was having fun. So here is a different implementation that moves the 'find' inside of the perl script:

#!/usr/bin/env bash
if [[ $# != 2 ]]; then
 echo 1>&2 "Usage: ${0##*/} /starting_directory /path/to/reference_file"
 exit 1
fi
START="$1"
REFFILE="$2"
perl -e '
 use File::Find;
 @ref = stat($ARGV[1]);
 find sub {
 @st = stat($File::Find::name);
 if ( $st[0] == $ref[0] && $st[1] == $ref[1] ) {
 print `ls -l "$_"`;
 }
 }, $ARGV[0];
' "$START" "$REFFILE"

j.v.'s solution is good, and it does not require that you understand perl (assuming you want to understand how the code works).

Also j.v. remembered to include the use of sudo, as there are a lot of directories that normal users will not be allowed access, unless they are root.

j.v. wrote:
find / -type l -print0 | xargs -0 ls -TalkOs | grep ' -> ' | grep diskPM

I think that this is equivalent to

find / -type l -ls | grep ' -> ' | grep diskPM

or to find all symbolic links (note: sudo needed to access all directories):

find / -type l -ls 

I think that this is equivalent to

find / -type l -ls | grep ' -> ' | grep diskPM

If you want to optimize, then why 2 grep's?

sudo find / -type l -ls | grep ' -> .*diskPM'

But j.v. still had more straight forward solution, and easier to understand then my install GNU 'find', or use perl (but I had fun writing the perl 🙂 ).

If you want to optimize, then why 2 grep's?

Just using j.v.'s example

But j.v. still had more straight forward solution, and easier to understand then my install GNU 'find', or use perl (but I had fun writing the perl 🙂 ).

Well, the OP wanted to "find all symbolic links pointing to a file", so

sudo find / -type l -ls

is the most straight-forward solution 🙂

well yeah, I guess I interpreted his problem as wanting to find all symlinks pointing to a specific file of interest, hence all the added gobbledygook, rather than just find every instance of a symbolic link resident on his hard drive (otherwise, his subject line might have only been "Find all symbolic links").

And you're right, I guess I could do away with one of the greps ( +| grep ' -> '+ )

From the command line:

find / -type l -exec test {} -ef /path/to/file \; -print

The approaches that use pipes will break on names containing whitespace, whereas find's -exec switch will handle them correctly.

corbaguy wrote:
From the command line:

find / -type l -exec test {} -ef /path/to/file \; -print

Why not just: find / -type l -ls

Because I interpreted the original question to mean "find all of the symbolic links pointing to +a particular+ file"

The approaches that use pipes will break on names containing whitespace, whereas find's -exec switch will handle them correctly.

Actually j.v.'s version which used -print0 and xargs -0 would not break. The -print0 passes the filenames nul terminated, and xargs -0 accepts nul terminated file names and passes them to the command being invoked as a single ARGV argument.

Also the ones that just do "find | grep" do not really care about spaces in paths.

That being said, your approach using 'test -ef' combines the simplicity of a command line solution and getting the accuracy of my perl solution. Very well done.

At the very least, I think the OP (GaryKing) should award you a "Helpful" star, and since I think yours is the shortest, straight forward and accurate, if I were the OP, I would give you the "Solved" award.

Actually, running an exec and test for each link does not seem efficient at all.

find / -type l -ls | fgrep "filename"

is not only more efficient, but will list partial filenames (why test for "Very Long Path To/A Very Long File Created By Tony.txt" when an fgrep for "Tony" will do