This scheme 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 all 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 BitKeeper, RCS, SCCS, .svn, CVS and CVS.adm directories are shadowed only if the -withrevinfo flag is specified.

If you add files, simply run lndir again. New files will be silently added. Old files will be checked that they have the correct link.

Deleting files is a more painful problem; the symlinks will just point into never never land.

If a file in fromdir is a symbolic link, lndir will make the same link in todir rather than making a link back to the (symbolic link) entry in fromdir. The -ignorelinks flag changes this behavior.

-silent

Normally lndir outputs the name of each subdirectory as it descends into it. The -silent option suppresses these status messages.

-ignorelinks

Causes the program to not treat symbolic links in fromdir specially. The link created in todir will point back to the corresponding (symbolic link) file in fromdir. If the link is to a directory, this is almost certainly the wrong thing.

This option exists mostly to emulate the behavior the C version of lndir had in X11R6. Its use is not recommended.

-withrevinfo

Causes any BitKeeper, RCS, SCCS, .svn, CVS and CVS.adm subdirectories to be treated as any other directory, rather than ignored.

A warning message is displayed if the symbolic link cannot be created. The usual problem is that a regular file of the same name already exists.

If the link already exists but doesn't point to the correct file, the program prints the link name and the location where it does point.