Perl 6 Joy.p6

# Read Makefile.in, edit, write Makefile
my $maketext = slurp( 'Makefile.in' );
$maketext .= subst( .key, .value ) for
    'Makefile.in' => 'Makefile',
    'To be read' => 'Written',
    'replaces <TOKENS>' => 'defined these',
# Maintainer note: keep the following in sync with pod#VARIABLES below
    '<PERL6>' => $perl6,
    '<PERL6LIB>' => $perl6lib,
    '<PERL6BIN>' => $perl6bin,
    '<RAKUDO_DIR>' => $rakudo_dir;
squirt( 'Makefile', $maketext );
 
# Job done.
.say for
    '',
    q[Makefile is ready, and you can run 'make'.];
 
# The opposite of slurp
sub squirt( Str $filename, Str $text ) {
    my $handle = open( $filename, :w )
        or die $!;
    $handle.print: $text;
    $handle.close;
}