Assuming the files are numbered with a fixed width, such as
three digits that you have here in your example, you can
sort the output of readdir and pick off the first entry.
If you're not familiar with this method, try this:
my $base_dir = "c:/data/";
my $new_dir = "d:/new/";
opendir (DIR, $base_dir)
|| die "Could not open data directory\n";
my ($top_file) = reverse sort readdir(DIR);
closedir (DIR);
Note that this is assigning the first element of the
sorted, reversed array from readdir into $top_file. As
sort usually goes from lowest to highest (i.e. a .. z),
using reverse will give you the highest.
If your files have a variable number of digits, this sort
routine will fail miserably, as the order will be something
like 1, 10, 11, 2, 20. You will have to write a "custom"
numerical sort routine:
my ($top_file) = reverse sort { ($a=~/\$(\d+)$/)<=>($b=~/\$(\d+)$/) } readdir(DIR);
Which has the effect of extracting the numerical component
from each entry (\d+ is one or more digits). An interesting
twist is that you can switch $a and $b and remove reverse
because you are now defining the sort rules.
To move the file from one drive to another is, if I recall
correctly, something that might require the use of File::Copy.
As in:
use File::Copy;
move($base_dir.$top_file, $new_dir.$top_file);
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[d/l]
[select] |
sort { $b cmp $a } is more efficient than reverse sort
- Ant
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I'll describe the tools you need to get this done, then leave the dirty work to you. :)
You can sort the filenames using sort(), and you can write your own comparison subroutine. See perlfunc:sort for details.
You can use substr() to get the number at the end. See perlfunc:substr for details.
You can use '<=>' to compare the numbers. See perlman:perlop for details.
stephen
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