This technique is adapted out of production C++ code that does something similar:

sub blank_formatter {
  my ($printf_format, $length) = @_;
  if (!defined($length))
  {
    $printf_format =~ /^%(\d+)/ or die "Can't deduce length from $prin
+tf_format";
    $length = $1;
  }
  my ($blank) = ' ' x $length;
  sub { $_[0] ? sprintf($printf_format,$_[0]) : $blank; };
}

sub my_printf
{
  my ($format, @args) = @_;
  my (@printfargs) = ();
  while (@args) {
    my $arg = shift @args;
    if (ref($arg) and ref($arg) eq 'CODE') {push @printfargs, $arg->(s
+hift @args);}
    else {push @printfargs, $arg;}
  }
  printf($format, @printfargs);
}
# similarly, if you need it, my_sprintf

# Was:
# printf( "A float: %12.4f$/", $root_beer );
my_printf( "A float: %s$/", blank_formatter('%12.4f'), $root_beer );
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Then, if you need it, you can get whole aligned tables with something like:

my $fmt = blank_formatter('%12.4f');
my_printf("%10s: %s %s %s %s\n", $rowname, 
          map {$fmt => $_} ($numcol1, $numcol2, $numcol3, $numcol4));
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Similarly for other complicated formatting requirements. Just define your format generator so that it returns a sub reference that will take the thing to be formatted and returns a string, and then use printf as normal with %s placeholders.

--
@/=map{[/./g]}qw/.h_nJ Xapou cets krht ele_ r_ra/;
map{y/X_/\n /;print}map{pop@$_}@/for@/
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