$ find2perl . -type d -name "*.rec"
#! /opt/local/perl/bin/perl -w
    eval 'exec /opt/local/perl/bin/perl -S $0 ${1+"$@"}'
        if 0; #$running_under_some_shell

use strict;
use File::Find ();

# Set the variable $File::Find::dont_use_nlink if you're using AFS,
# since AFS cheats.

# for the convenience of &wanted calls, including -eval statements:
use vars qw/*name *dir *prune/;
*name   = *File::Find::name;
*dir    = *File::Find::dir;
*prune  = *File::Find::prune;

sub wanted;



# Traverse desired filesystems
File::Find::find({wanted => \&wanted}, '.');
exit;


sub wanted {
    my ($dev,$ino,$mode,$nlink,$uid,$gid);

    (($dev,$ino,$mode,$nlink,$uid,$gid) = lstat($_)) &&
    -d _ &&
    /^.*\.rec\z/s
    && print("$name\n");
}

#! /usr/bin/perl
use strict;
use warnings;
use 5.010;

use File::Find;

my $basedir = ".";
my $extension = ".rec";

my @matched_dirs;

sub wanted {
    # $File::Find::dir is the current directory name,
    # $_ is the current filename within that directory
    # $File::Find::name is the complete pathname to the file.

    push @matched_dirs, $File::Find::name
      if -d $_ && $_ =~ m/\Q$extension\E$/;

}

find( \&wanted, $basedir );

say "I have found:";
say $_ for @matched_dirs;