How to symlink a file in Linux?

Question

I want to make a symbolic link in Linux. I have written this bash command where the first path is the folder I want link into and the second path is the compiled source.

ln -s '+basebuild+'/IpDome-kernel/kernel /home/build/sandbox/gen2/basebuild/IpDome-kernel/kernal 

Is this correct?

Answer 1

There are two types of links:

symbolic links: Refer to a symbolic path indicating the abstract location of another file

hard links: Refer to the specific location of physical data.

In your case symlinks:

ln -s source target

you can refer to http://man7.org/linux/man-pages/man7/symlink.7.html

you can create too hard links

A hard link to a file is indistinguishable from the original directory entry; any changes to a file are effectively independent of the name used to reference the file. Hard links may not normally refer to directories and may not span file systems.

ln source link

Answer 2

ln -s source_file target_file

http://unixhelp.ed.ac.uk/CGI/man-cgi?ln

Answer 3

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

Answer 4

I'd like to present a plainer-English version of the descriptions already presented.

 ln -s  /path-text/of-symbolic-link  /path/to/file-to-hold-that-text

The "ln" command creates a link-FILE, and the "-s" specifies that the type of link will be symbolic. An example of a symbolic-link file can be found in a WINE installation (using "ls -la" to show one line of the directory contents):

 lrwxrwxrwx 1 me power 11 Jan  1 00:01 a: -> /mnt/floppy

Standard file-info stuff is at left (although note the first character is an "l" for "link"); the file-name is "a:" and the "->" also indicates the file is a link. It basically tells WINE how Windows "Drive A:" is to be associated with a floppy drive in Linux. To actually create a symbolic link SIMILAR to that (in current directory, and to actually do this for WINE is more complicated; use the "winecfg" utility):

 ln -s  /mnt/floppy  a:   //will not work if file a: already exists

Answer 5

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.

Answer 6

ln -s EXISTING_FILE_OR_DIRECTORY SYMLINK_NAME