Soft (symbolic) Link Example

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  • Essential Linux
    • Wildcards and Links
      • File Links
        • Soft (symbolic) Link Example

Again, let us assume that the current working directory is /home/john and we wish to create a link 'softfile2' within the subdirectory projects to the file 'softfile'. Notice the '-s' switch:

% date > softfile  ( create the file )

% ls -l 
-rwx-xr-x  1 john users 605 Nov 18 12:25 softfile

% ln -s /home/john/softfile project/softfile2

% ls -l projects/softfile2
lrwx-xr-x  1 john users 605 Nov 18 12:25 softfile2 ->
                 /home/staff/john/softfile

Notice the appended pathname on the long listing, the link number has not changed, but the permissions show an 'l' at the beginning of the long listing rather than a '-'. Again any updates in 'softfile' will be reflected in 'softfile2'. A common symbolic link for programmers is to have a link named 'core' that points to /dev/null. Core files are generated when a program 'core dumps' or produces debugging output. These core files take up a tremendous amount of storage, and are use rarely by anyone. The special file /dev/null is the Unix equivalent of a trashcan. In effect, what you are doing is telling the system to scrap the file whenever an attempt is made to create it.

% ln -s /dev/null core
% ls -l core
lrwx-xr-x  1 john users 9 Nov 18 12:26 core -> /dev/null

With symbolic links you can remove the 'real' file and the symbolic list will still exist.

Copyright @ 2004-2012 Gordon Russell. All rights reserved.