How can I symlink a file in Linux?

To create a new symlink (will fail if symlink exists already):

ln -s /path/to/file /path/to/symlink

To create or update a symlink:

ln -sf /path/to/file /path/to/symlink

ln -s TARGET LINK_NAME

Where the -s makes it symbolic.

ln -s EXISTING_FILE_OR_DIRECTORY SYMLINK_NAME

ln -s target linkName

You can have a look at the man page here:

http://linux.die.net/man/1/ln

ln [-Ffhinsv] source_file [target_file]

    link, ln -- make links

        -s    Create a symbolic link.

    A symbolic link contains the name of the file to which it is linked. 

    An ln command appeared in Version 1 AT&T UNIX.

This is Stack Overflow so I assume you want code:

All following code assumes that you want to create a symbolic link named /tmp/link that links to /tmp/realfile.

CAUTION: Although this code checks for errors, it does NOT check if /tmp/realfile actually exists ! This is because a dead link is still valid and depending on your code you might (rarely) want to create the link before the real file.

Shell (bash, zsh, ...)

#!/bin/sh
ln -s /tmp/realfile /tmp/link

Real simple, just like you would do it on the command line (which is the shell). All error handling is done by the shell interpreter. This code assumes that you have a working shell interpreter at /bin/sh .

If needed you could still implement your own error handling by using the $? variable which will only be set to 0 if the link was successfully created.

C and C++

#include <unistd.h>
#include <stdio.h>

int main () {
  if( symlink("/tmp/realfile", "/tmp/link") != 0 )
    perror("Can't create the symlink");
}

symlink only returns 0 when the link can be created. In other cases I'm using perror to tell more about the problem.

Perl

#!/usr/bin/perl
if( symlink("/tmp/realfile", "/tmp/link") != 1) {
  print STDERR "Can't create the symlink: $!\n"
}

This code assumes you have a perl 5 interpreter at /usr/bin/perl. symlink only returns 1 if the link can be created. In other cases I'm printing the failure reason to the standard error output.

Links are basically of two types:

Symbolic links (soft): link to a symbolic path indicating the abstract location of another file

Hard links: link to the specific location of physical data.

Example 1:

ln /root/file1 /root/file2

The above is an example of a hard link where you can have a copy of your physical data.

Example 2:

ln -s /path/to/file1.txt /path/to/file2.txt

The above command will create a symbolic link to file1.txt.

If you delete a source file then you won't have anything to the destination in soft.

When you do:

ls -lai

You'll see that there is a different inode number for the symlinks.

For more details, you can read the man page of ln on your Linux OS.

I find a bit confusing the terminologies "target" and "directory" in the man information.

The target is the folder that we are symlinking to and the directory the actual symlink (not the directory that you will be symlinking to), if anyone is experiencing the same confusion, don't feel alone.

This is my interpretation of creating a Symlink (in linux):

ln -s /FULL/PATH/FOLDER-OR-FILE-SYMLINKING-TO NAME-OF-YOUR-SYMLINK

You can navigate to the folder where you want to create the symlink and run the command or specify the FULL PATH for your symlink instead of NAME-OF-YOUR-SYMLINK.

cd /FULL/PATH/TO/MY-SYMLINK-PARENT-FOLDER
ln -s /FULL/PATH/FOLDER-OR-FILE-SYMLINKING-TO NAME-OF-YOUR-SYMLINK

OR

ln -s /FULL/PATH/FOLDER-OR-FILE-SYMLINKING-TO /FULL/PATH/TO/MY-SYMLINK-PARENT-FOLDER/NAME-OF-YOUR-SYMLINK

I hope this helps to those (still) slighly confused.