code i used:

<?php
$pdformp = fopen("./test.dat", "w");
$fdf = fdf_open_string($HTTP_FDF_DATA);
while ($field = fdf_next_field_name($fdf, $field)) {
	echo "$field is of type " . gettype ( fdf_get_value ( $fdf, $field ) ) . " \"" . fdf_get_value ( $fdf, $field ) . "\" ";
	fwrite($pdformp, "$field=" . fdf_get_value ( $fdf, $field ) . "\n");
}
fdf_close($fdf);
fclose($pdformp);
?>

Assigned to the maintainer.

I have a pdf file with a text field (FooField) that can exceed 255 characters in length.  I submit the form data using javascript command:
this.submitForm ("http://urlname/Submit_Form.php");

In Submit_Form.php....

$fdf = fdf_open_string(file_get_contents("php://input"));
$str = fdf_save_string($fdf);
//(the echo $str shows that all of the text string is their even if the string length exceeds 255 characters)
echo $str;

but... if I try to extract the value using:

$FooField=fdf_get_value($fdf, "FooField");

I get the correct results for strings up to 255 characters
but I get NULL as a result for strings > 255 chaaracters.

We are sorry, but we can not support PHP 4 related problems anymore.
Momentum is gathering for PHP 6, and we think supporting PHP 4 will
lead to a waste of resources which we want to put into getting PHP 6
ready.