$ perl -E 'my $x = "  xyz  "; say "|$_|" for map /^\s*(.+)$/, $x'
|xyz  |

$ perl -E 'my $x = "  xyz  "; say "|$_|" for map /^\s*(.+)\s*$/, $x'
|xyz  |

$ perl -E 'my $x = "  xyz  "; say "|$_|" for map /^\s*(.+?)\s*$/, $x'
|xyz|