Thanks to both of you kind souls for the replies. Matija, I tried to alter my code according to your recommendations, but I keep getting a syntax error. Here is what the code looks like now:

use strict;
open OUTPUT, ">c:/temp/warning.txt";
my @directories = ('F:\Solimar_Work_Directories\XVTP\XVTP Cluster Feed
+', 'G:\Solimar_Work_Directories\XVTP\XVTP Cluster Feed', 'G:\XVTPInpu
+t', 'G:\XVTPInput\DBQA_input', 'G:\XVTPInput\DB_Input');
my $mytime=(time);
my ($File,$FileStat,$CallOutDir);
foreach my $dir (@directories)
opendir(ROOT,$dir) or die "Directory <$dir> failed: $!";
foreach my $F (readdir(ROOT)) {
$File="$dir/$F";
foreach $File (readdir(ROOT)) {
    next if $File=~/^\./; 
    next if ($File eq "_Watched_Folder_._Active_");
    next if ($File=~/\._Checking_File_Readiness_$/); 
        if ($FileStat = (stat $File)[9]){
        if ($FileStat <= ($mytime - 300)) {
        print "File older than 5min found. The file name is $File";
        print OUTPUT "File older than 5min found. The file name is $Fi
+le";
        last;
        }
    }
}
}
close OUTPUT;
[download]

The error I get is:

$ perl -c watchdir_revc.pl
syntax error at watchdir_revc.pl line 18,
opendir"
watchdir_revc.pl had compilation errors.
[download]