How to find the original file of a soft link?

Question

For example, I have a file a, and I do the followings.

ln -s a b
ln -s b c
ln -s c d

If I use readlink d, I will get c. So I have to run many times to get a.

Is there an easy way to get a?

Update:

If I want to locate the original file of /usr/bin/java, I have to do it many times to get /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java. The files and links are not in the same folder.

For macOS Catalina try - readlink -n which command – Manyam Nandeesh Reddy Apr 01 '21 at 21:04 — Manyam Nandeesh Reddy, Apr 01 '21 at 21:04

score 8 · Accepted Answer · edited Dec 13 '13 at 21:41

8

Command for following chains of links is named namei^ManPage. Examples:

$ touch a
$ ln -s a b
$ ln -s b c
$ ln -s c d
$ namei ./d
f: ./d
 d .
 l d -> c
   l c -> b
     l b -> a
       - a
$ namei /usr/bin/java
f: /usr/bin/java
 d /
 d usr
 d bin
 l java -> /etc/alternatives/java
   d /
   d etc
   d alternatives
   l java -> /usr/lib/jvm/java-7-openjdk-i386/jre/bin/java
     d /
     d usr
     d lib
     d jvm
     d java-7-openjdk-i386
     d jre
     d bin
     - java

edited Dec 13 '13 at 21:41

Rmano

31,947

answered Nov 07 '13 at 23:22

Nykakin

3,744

Maybe this is what I am looking for! Thanks a lot! – eccstartup Nov 08 '13 at 03:19

Radu Rădeanu · Answer 2 · 2013-11-07T18:06:27.163

You can use the following shell function:

readmultilink () {
    linkfile="$1"
    if [ ! -L "$linkfile" ]; then 
        echo "$linkfile is not a simbolik link" >&2
        return 1
    fi
    until [ ! -L "$linkfile" ]; do
        lastlinkfile="$linkfile"
        linkfile=$(readlink "$lastlinkfile")
    done
    readlink "$lastlinkfile"
}

Add this function at the end of your ~/.bashrc file if you want to use it every time when you open the terminal.

Usage:

readmultilinks file_name

As example, for your example, readmultilinks d, readmultilinks c, and readmultilinks b will return a, but readmultilinks a will return a is not a simbolik link.

score 2 · Answer 3 · answered Jan 30 '14 at 20:55

2

A simple solution:

readlink -f /path/to/file

answered Jan 30 '14 at 20:55

kiri

28,246
16
81
118

score 1 · Answer 4 · answered Nov 07 '13 at 04:00

1

You maybe need find instead:

$ find -L . -samefile d
./b
./c
./d
./a

Or:

$ ls -i d
143075 d
$ find . -follow -print -inum 143075
.
./b
./c
./d
./a

Both cases the original file is the last one.

answered Nov 07 '13 at 04:00

Braiam

67,791
32
179
269

These cases will only locate files in the given folder. – eccstartup Nov 07 '13 at 04:36
@eccstartup you only have to change . for the directory you like, ie /, but they will take time. – Braiam Nov 07 '13 at 04:38
What is the result on your computer? If the link is /usr/bin/java? – eccstartup Nov 07 '13 at 04:41
@eccstartup beats me... I don't have/use java, Also, it will depends what version of java you install, but I gave you a general solution for all sort of problems. – Braiam Nov 07 '13 at 04:46
Well, I get many many results. If I redirect the result into a file, the size of the file is over 10MB, and it is increasing because I kill it with Ctrl+C. – eccstartup Nov 07 '13 at 04:53

How to find the original file of a soft link?

4 Answers4

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