After MidLifeXis mentioned the race condition which is unfortunately included in my previous solution, I would like to present another solution, which uses umask.

What about this solution?

#!/usr/bin/perl
# vi:ts=4 sw=4 et:
use strict;
use warnings;
use File::Spec::Functions   qw( catdir );

my $dir = '/home/me/perl-stuff';

# obtain type and permissions and strip off type information; see: per
+ldoc -f stat
my $mask = ( stat $dir )[2] & 07777;

# path of new directory
$dir = catdir( $dir, 'new_dir' );

# set new calculated umask and store old value; see: perldoc -f umask
my $old_umask = umask 0777-$mask;

# create directory; see: perldoc -f mkdir
mkdir( $dir ) or die $!;

# restore old umask value
umask $old_umask;

__END__
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