(PHP 4 >= 4.0.5, PECL pdflib >= 1.0.0)
PDF_attach_file — Add file attachment for current page [deprecated]
Adds a file attachment annotation. 成功时返回 TRUE, 或者在失败时返回 FALSE.
This function is deprecated since PDFlib version 6, use PDF_create_annotation() with type=FileAttachment instead.