How can I change the symlink path for many files?

• It's a bit difficult, but it can be done using find
  
  , readlink
  
  , checks to verify whether the symbolic link relative or not, and sed
  
  to get rid of ..
  
  the way names (copied 1: 1 from the answer ).
  (Note that most convenience methods (for example readlink -f
  
  ) are not available due to the unavailability of existing symlinks.)
  Assuming your old path /var/lib/old/path
  
  :

  oldpath='/var/lib/old/path';
  find / -type l -execdir bash -c 'p="$(readlink "{}")"; if [ "${p:0:1}" != "/" ]; then p="$(echo "$(pwd)/$p" | sed -e "s|/\./|/|g" -e ":a" -e "s|/[^/]*/\.\./|/|" -e "t a")"; fi; if [ "${p:0:'${#oldpath}'}" == "'"$oldpath"'" ]; then ...; fi;' \;
  
        
  
          
          
          
        
  
      

• Now replace the ...
  
  top with ln -sf
  
  ( -f
  
  to override the existing link).
  Assuming your new path is /usr/local/my/awesome/new/path
  
  :

  oldpath='/var/lib/old/path';
  newpath='/usr/local/my/awesome/new/path';
  find / -type l -execdir bash -c 'p="$(readlink "{}")"; if [ "${p:0:1}" != "/" ]; then p="$(echo "$(pwd)/$p" | sed -e "s|/\./|/|g" -e ":a" -e "s|/[^/]*/\.\./|/|" -e "t a")"; fi; if [ "${p:0:'${#oldpath}'}" == "'"$oldpath"'" ]; then ln -sf "'"$newpath"'${p:'${#oldpath}'}" "{}"; fi;' \;
  
        
  
          
          
          
        
  
      

Note that oldpath

and newpath

must be absolute paths.
Also note that this will convert all relative symbolic links to absolute.
One could keep them relative, but only with great effort.

Destruction

For those of you who care what that means one-line hell,

• find
  
  - cool executable file
• /
  
  - where to look, in this case the system root
• -type l
  
  - matching symbolic links
• -execdir
  
  - for each match, the following command is launched in the directory of the corresponding file:
  • bash
    
    - well, bash
  • -c
    
    - execute the following line (delete and delete '
    
    ):
    • p="$(readlink "{}")";
      
      - starting from the innermost:
      • "
        
        - run the line to make sure there is no extension.
      • {}
        
        - placeholder for the name of the associated file (function -execdir
        
        )
      • "
        
        - end of line
      • readlink ...
        
        - find out where the symlink points to
      • p="$(...)"
        
        - and save the result to $p
        
        
    • if [ "${p:0:1}" != "/" ]; then
      
      - if the first character $p
      
      is equal /
      
      (i.e. the symlink is absolute) then ...
    • p="$(echo "$(pwd)/$p" | sed -e "s|/\./|/|g" -e ":a" -e "s|/[^/]*/\.\./|/|" -e "t a")";
      
      - convert path to absolute:
      • $(pwd)
        
        - the current directory (where the match file is, because we are using -execdir
        
        )
      • /$p
        
        - add forward slash and target of symbolic link to working directory path
      • echo "$(pwd)/$p" |
        
        - translate the above command to the next command
      • sed ...
        
        - allow everything ..
        
        , see here
      • p="$(...)"
        
        and cast the result back to $p
        
        .
    • fi;
      
      - end if
      
      
    • if [ "${p:0:'${#oldpath}'}" == "'"$oldpath"'" ];
      
      - if it $p
      
      starts with$oldpath
      
      
      • ${p:0:'${#oldpath}'}
        
        - substring $p
        
        starting from position 0
        
        with length $oldpath
        
        :
        • ${#oldpath}
          
          - variable length $oldpath
          
          
        • '...'
          
          - required because we are inside the '
          
          -quoted line
    • then
      
      - then ...
    • ln -sf
      
      - link symbolically and override existing file with arguments:
      • "'"$newpath"'${p:'${#oldpath}'}"
        
        - replace the $oldpath
        
        part $p
        
        with $newpath
        
        (actually remove as many characters from $p
        
        as $oldpath
        
        long and add to it $newpath
        
        ):
        • "
          
          - run the line
        • '
          
          - complete the '
          
          -string argument beforebash -c
          
          
        • "
          
          - add to it a line "
          
          (in which the variable is expanded) containing:
        • $newpath
          
          - value $newpath
          
          
        • "
          
          - complete the "
          
          -string argument beforebash -c
          
          
        • '
          
          - add to it a line '
          
          containing:
        • ${p:
          
          - substring p
          
          starting with:
        • '
          
          - complete the argument bash -c
          
          
        • ${#oldpath}
          
          - add length to it $oldpath
          
          
        • '
          
          - add another '
          
          jet to it
        • }
          
          - end of substring
        • "
          
          - end of line
      • "{}"
        
        - a link file whose path remains the same
    • fi;
      
      - end if
      
      
• \;
  
  - separator for -execdir