New attribute for DBD::File

In the git branch "f_dir-ref" (a wrong name now, as we changed some
things in the development process), you can find a new extension

DBD::File now understands a new attribute f_dir_search:

  f_dir_search

    This optional attribute can be set to pass a list of folders to also
    find existing tables. It will not be used to create new files.

      f_dir_search => [ "/data/bar/csv", "/dump/blargh/data" ],

A real-world example might explain this in more detail using DBD::CSV

my $dbh = DBI->connect ("dbi:CSV:", undef, undef, {
    f_schema         => undef,
    f_dir            => "tmp",
    f_dir_search     => [ "sandbox", "/tmp" ],
    f_ext            => ".csv/r",
    f_lock           => 2,
    f_encoding       => "utf8",

    RaiseError       => 1,
    PrintError       => 1,
    FetchHashKeyName => "NAME_lc",
    }) or die "$DBI::errstr\n";

This will set the default folder for CSV files to be located in the
folder "tmp". This folder will also be used for creating tables.

When opening a handle to an already existing table, and that table's
file(s) cannot be found in the folder indicated by "f_dir", the folders
in the "f_dir"search" (if present) will be searched for the files
needed to open the table.

  my $sth = $dbh->prepare ("select * from foo");

will, using the above example, search for

  tmp/foo.csv
  sandbox/foo.csv
  /tmp/foo.csv

The DBI test suite tests this option in t/51dbm_file.t

If people have feedback, it would be appreciated. Both possitive and
negative. If no objections exist, I'd like to merge this branch into
master and request a new release, so we can release DBD::CSV shortly
after

-- 
H.Merijn Brand  http://tux.nl   Perl Monger  http://amsterdam.pm.org/
using perl5.00307 .. 5.19   porting perl5 on HP-UX, AIX, and openSUSE
http://mirrors.develooper.com/hpux/        http://www.test-smoke.org/
http://qa.perl.org   http://www.goldmark.org/jeff/stupid-disclaimers/