perl -e 'sub c { my $w = shift; if ($#_) { for $i (0..$#_) { my @w = @_; &c ($w . splice (@w, $i, 1), @w); } } else { $p{ $w . $_[0] } = q() } }; &c ( q(), split //, $ARGV[0] ); $\ = qq(\n); open D, q(/usr/share/dict/words); while(<D>) { chomp; s!\s+!!; print if exists $p{$_}; }' ___LETTERS___