This has the advantage that if you update the source, you need not propagate the change to the other architectures by hand, since all source in shadow directories are symlinks to the real thing: just cd to the shadow directory and recompile away.
The todir argument is optional and defaults to the current directory. The fromdir argument may be relative (e.g., ../src) and is relative to todir (not the current directory).
Note that RCS, SCCS, and CVS.adm directories are not shadowed.
If you add files, simply run lndir again. Deleting files is a more painful problem; the symlinks will just point into never never land.
You need to use something like find todir -type l -print | xargs rm
to clear out all files before you can relink (if fromdir moved, for instance). Something like find . \! -type d -print
will find all files that are not directories.