#!/usr/bin/perl -w

use strict;

# Also tried with this, but with no better results
#use POSIX qw/locale_h/;
#setlocale(LC_CTYPE, "pt_PT.ISO8859-1");

use locale;

my @words = qw/η q αγη abc/;

foreach (@words) {
	$_ =~/[[:alpha:]]/ 
		? print "$_ : OK!\n" 
		: print "$_ : NOT OK!\n";

	$_ =~/\w+/ 
		? print "$_ : OK!\n" 
		: print "$_ : NOT OK!\n";
}

__DATA__
Output:
η : OK!
η : OK!
q : OK!
q : OK!
αγη : OK!
αγη : OK!
abc : OK!
abc : OK!