The development track

• The next temptation

  Nesting formats

        #!/usr/bin/perl -w
  
        use strict;
  
        format HEADER =
        HEADER
        .
        sub HEADER ()
        {
  	  local $~ = "HEADER";
  	  my $HEADER;
  	  open HEADER, ">", \$HEADER;
  	  select HEADER;
  	  write;
  	  close HEADER;
  	  select STDOUT;
  	  $HEADER;
  	  } # HEADER
        format STDOUT_TOP =
        TOP
        @<<<<<
        @{[HEADER]}
        .
        format STDOUT =
        STDOUT
        @<<<<
        $%
        .
        write;

  Expected output

        TOP
        HEADER
        STDOUT
        1

  Produced output

        page overflow at format2_pl line 19.
        STDOUT
        0
        TOP
        HEADER