How do I add a PostScript XObject to a PDF?

I am demoing an idea I have been playing around with, and while the Adobe specification says that including PS XObjects is not a good idea, some PDF readers should still support this functionality. Anyways, that is beside the fact. I have been using the Adobe PDF specification and have the following PDF object. This merely uses PostScript to generate a pseudo random value and then print it to the page. Ideally, each time this page is rendered a new value should display:

5 0 obj
<< /Type/XObject
   /Subtype/PS
   /Length 103
>>
stream
/Times findfont 10 scalefont setfont
/str 32 string def
10 20 moveto
rand str cvs show
endstream
endobj

Each time any PDF viewer I have tested this against reads this object I get开发者_开发技巧 errors such as:"Error (741): Missing 'endstream'" And similarly for every token in that stream. I am sure my offsets are correct. And while I know my PDF viewer does support some PS for forms and such, is there anything obviously incorrect. If anyone has a sample PDF I can go from, that would be nice. The form examples that I tested my reader against have not been too helpful. If I run just the PS code from GhostView it works fine. Thanks for any insight.

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I've scoured my back collection of PDF files and come up with 2 which contain PS XObjects (this really is deprecated). I can't, unfortunately, share tehm as they are customer data files :-(

However, here is an extract from one of them:

74 0 obj
<<
/Type /XObject
/Subtype /PS
/Filter /FlateDecode
/Length 77 0 R
/Name /Ps1
>>
stream
....endstream

Note 1, there is no EOL between the end of data and the 'endstream' token.

77 0 obj
4480
endobj

The offset of the 0x0A following the 'stream' token is 0xdab15, the offset of the 'e' in endstream is 0xdbc96. That is 4481 bytes. SO it looks to me like the /Length should contain all the bytes after the EOL for the 'stream' token' right up to the last byte before the 'e' in the endstream token.

I think it would be OK to insert a 0x0A after the stream data and before the endstream. That would come down to a whitespace after the stream data before the token, and PDF is supposed to be tolerant of whitespace.

This is consistent with the description of the /Length entry for stream dictionaries in Table 3.4 (p62 of the 1.7 PDF reference):

The number of bytes from the beginning of the line fol-lowing the keyword stream to the last byte just before the keyword endstream. (There may be an additional EOL marker, preceding endstream, that is not included in the count and is not logically part of the stream data.) See “Stream Extent,” above, for further discussion.

I think (if I've counted correctly) that the /Length in your example should be 87, assuming one byte line terminators in the PostScript fragment.