#22 flexbackup subtle subtree pruning issue

[John R. Graham]

When you specify a list of directories to prune, flexbackup gets it almost right. It backs up all of the directories on the pruning list but none of the contents of those directories. As such, little space is wasted in the backup and it's more if a nit than a real show stopper.

The issue was that flexbackup was taking the list of directories, for instance, like this one:

$prune{'/home'} = "bert ernie bigbird";

from its conf file and constructing a regular expression (that's passed on the command line of "find") like this (necessary shell escaping omitted for
clarity):

-regex "\./(bert|ernie|bigbird)/.*" -prune

The "/.*" on the end of the regular expression ensured that any file under the listed directories would match and be pruned but, because of the trailing slash, the directory itself *would not* be matched. The solution was to omit the last two atoms of the regular expression, resulting in:

-regex "\./(bert|ernie|bigbird)" -prune

This results in each directory itself being pruned (which is what was wanted all along). Since each directory is pruned, there's no need to match their
contents.

A patch is attached that corrects this issue and adds some tutorial comments on the pruning mechanism to the flexbackup.conf file.

[John R. Graham]