#!/usr/bin/perl

use Getopt::Long;
use strict;
use warnings;
$|=1;

my $srcdir;
my $destdir;
my $mtime = 1;

GetOptions(
        'srcdir=s' => \$srcdir,
        'destdir=s' => \$destdir,
        'mtime|days=i' => \$mtime,
);

defined $srcdir && defined $destdir or die <<EOF;
Usage: $0 --srcdir SRCDIR --destdir DESTDIR [-days N]
EOF

opendir SRCDIR, $srcdir or die "opendir $srcdir - $!";

my @too_old;
my @files;

# only select non-hidden regular files:
for ( grep { -f "$srcdir/$_" } readdir SRCDIR )
{
        if ( -M "$srcdir/$_" > $mtime )
        {
                push @too_old, $_;
        }
        else
        {
                push @files, $_;
        }
}

closedir SRCDIR;

@too_old and
print "(Ignoring ".scalar(@too_old)." too-old files.)\n";

@files or die "No backup candidates in $srcdir.";

unless ( -d $destdir )
{
        warn "Destination directory $destdir does not exist; attempting to create.\n";
        mkdir $destdir or die "mkdir $destdir - $!";
}

print "Backing up ".scalar(@files)." files from $srcdir.\n";

for my $f ( @files )
{
        print "Archiving $f \n";
        system qq( cd "$srcdir" ; tar -cz "$f" -f "$f.tar.gz" );
        system qq( mv "$srcdir/$f.tar.gz" "$destdir" );
}