Wow - more than 10 years and somehow I missed your reply.

Here is a usage, roughly transcribed from what would happen in the Real World:

my $struct = <<'DEF';
       * Some comment
       05 AMOUNT     VALUE PIC S9(5)V99.
       05 VALUE-DATE VALUE PIC X(8).
DEF

my @lines = split /\n/, $struct;
my $buffer = '';
for my $line (@lines) {
    next if $line =~ /^      \*/; # comment
    $buffer .= $line;
    next unless $buffer =~ /\./; # the line did not end, we need more

    $buffer =~ /^\s+(\d+)\s+(.+)/;
        or croak "Weirdo input found: $buffer";
    my( $level, $info) = ($1,$2);
    if( $level == 1 ) {
        # A record or group, ignore
    } elsif ($info !~ /^(\S+)\s*(REDEFINES\s+(\S+))?\s*(PIC\s+[9XS].*?
+\.$/) {
        croak "Weirdo info found: $info";
    };
    my $name = $1;
    my $redefine = $2;
    my $pic = $3;
    my $size = 0;
    my $decoder = sub { $_[0] };
    if( $pic ) {
        ($size, $decoder) = PIC::decode_pic($pic,$decimal_separator,$e
+ncoding);
    };
    # ... use $size and $decoder to read and decode a number of bytes
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