Help with shell script: Find Recently Modified Directories

Question

I'm trying to do something that appears to be beyond my capacity to figure out on my own. I'm hoping that someone more skilled than I at scripting can help.
Challenge
I'm trying to build a script that finds directories and gzips each individually, but only if they've been modified within the last, say, 7 days.
Context
The idea is to create a set of gzipped directories that can then be uploaded to a remote server for backup and archival purposes. Since the parent directory is 8+ GB in size, and 99% of the contents does not change from week to week, I want to identify, zip, and upload only the directories that have been modified recently. (Uploading is outside the scope of this script).
*Cut to the Chase*
In plain english, my script might look like:
1) find sub-folders contained within "~/Sites/" that have been modified within the last 7 days; do not go more than 1 level deep (i.e., return only the top level folders within ~/Sites/)
2) loop through the returned list and gzip each directory
I'm hoping that this can be done easily. Automator doesn't provide filters that are granular enough to do this, so I'm thinking bash is the way to go. Any help would be most appreciated, and will be rewarded with all kinds of good karma. =)
-Steve

Answer 1

OK, here is an untested and possibly syntactically incorrect Perl script:
#!/usr/bin/perl -w
use strict;
my $siteDir = "$ENV{HOME}/Sites";
# Get all the top-level contents of the Sites directory.
opendir(SITES, $siteDir) or die "Couldn't open $siteDir folder.
my @siteContents = readdir SITES;
closedir SITES;
# Reset my script startup time to be 7 days ago.
$^T = time - (6060*247);
# Now find all the modified directories since then.
my @modifiedSiteDirs = grep { -d "$siteDir/$_" and -M "$siteDir/$_" < 7 } @siteDirs;
foreach my $modifiedSiteDir (@modifiedSiteDirs)
system qq{tar zcf "$modifiedSiteDir.tar.gz" $modifiedSiteDir};
Actually, I did just test it with only a printout instead of executing tar and it works. I'm not sure of the path to tar on MacOS X. You may have to add that.