This header describes PDFlib 4.0.2. Later PDFlib releases change API names and argument types; a modern library cannot be substituted just by renaming its archive. The library and its compression/image dependencies must also match the executable's target architecture.

The original 4.0.2 source is available from the GnuWin32 PDFlib archive. The source ZIP is pdflib-4.0.2-src.zip, with SHA-256 f1fb0952dcd7387fed48607a83da89bf8e854bf39ff6299b801a33367d08fc27. Retain the publisher's license files when building or redistributing this SDK.

Native Windows 32-bit and 64-bit and Linux amd64 qualification covers file output, a streaming output callback and in-memory output, with text and GIF images. The source archive has a failed-file-open cleanup defect; build_scripts/patches/pdflib4-open-file-cleanup.patch repairs it for a private SDK build. The unpatched library can retain document allocations after PDF_open_file fails and PDF_delete is called.

The bundled TIFF header also assumes that C long occupies four bytes. On Linux amd64 it occupies eight bytes, although TIFF file fields remain 32 bits. Apply build_scripts/patches/pdflib4-tiff-lp64.patch when building that dependency from this archive on an LP64 target. The patch selects the type from the actual C width and preserves the Windows layout. Native checks cover an independently encoded odd-width TIFF, guarded scanlines and decoded pixels, as well as independently parsed and rendered PDF output.

PDFlib's C int parameters and results use FreeBASIC Long, including the negative error results. C long uses clong from crt/long.bi, which follows the target ABI. Callback byte counts use native unsigned UInteger for C size_t. Allocation and reallocation callbacks return pointers, and a write callback returns the number of bytes actually accepted.

Keep callbacks and their application data valid until PDF_delete. PDF_new2 may call the allocator with a null PDF pointer before the object exists. Return from a nonfatal error handler, but terminate or unwind on a fatal error, as required by PDFlib. A custom handler must not return into a failed operation.

PDF_get_buffer returns borrowed bytes belonging to the PDF object. Copy the exact returned byte count before another PDFlib operation or deletion. The data is binary and can contain null bytes. Close each image handle after its last placement, then end the page, close the document and delete the object.

Build examples/files/pdflib/test.bas with a matching PDFlib 4.0.2 SDK. It accepts an optional output filename and GIF logo filename, for example test result.pdf path/to/fblogo.gif. The default output is pdflib_test.pdf; the library opens it for writing and replaces its previous contents.

The example checks object creation, file-open errors and font handles. A missing logo is reported and the page is generated without it. Resource filenames are limited to 1023 bytes to fit the version 4 filename buffers. Set FB_EXAMPLE_AUTOPLAY=1 for a bounded run without the final keyboard pause.