linux - How to generate plain-text source-code PDF examples that work in a document viewer?

Question

I just found the post Adobe Forums: Simple Text String Example in specification broken., so I got interested in finding plain-text source code PDF examples.

So, through that post, I eventually found:

• The webpage PDF Reference and Adobe Extensions to the PDF Specification | Adobe Developer Connection ; which contains:
  • The PDF Document Management – Portable Document Format – Part 1: PDF 1.7, First Edition (PDF32000_2008.pdf)

The PDF 1.7 spec has on page 699 appendix "_Annex H (informative) Example PDF files"; and from there, I wanted to try "H.3 Simple Text String Example" (the "classic Hello World").

So I tried to save this as hello.pdf (_except note when you copy from the PDF32000_2008.pdf, you may get "%PDF-1. 4" - that is, a space inserted after 1., which must be removed_) :

%PDF-1.4
1 0 obj
  << /Type /Catalog
      /Outlines 2 0 R
      /Pages 3 0 R
  >>
endobj

2 0 obj
  << /Type /Outlines
      /Count 0
  >>
endobj

3 0 obj
  << /Type /Pages
      /Kids [ 4 0 R ]
      /Count 1
  >>
endobj

4 0 obj
  << /Type /Page
      /Parent 3 0 R
      /MediaBox [ 0 0 612 792 ]
      /Contents 5 0 R
      /Resources << /ProcSet 6 0 R
      /Font << /F1 7 0 R >>
  >>
>>
endobj

5 0 obj
  << /Length 73 >>
stream
  BT
    /F1 24 Tf
    100 100 Td
    ( Hello World ) Tj
  ET
endstream
endobj

... and I'm trying to open it:

evince hello.pdf

... however, evince cannot open it: "Unable to open document / PDF document is damaged"; and also:

Error: PDF file is damaged - attempting to reconstruct xref table...
Error: Couldn't find trailer dictionary
Error: Couldn't read xref table

I also check with qpdf:

$ qpdf --check hello.pdf
WARNING: hello.pdf: file is damaged
WARNING: hello.pdf: can't find startxref
WARNING: hello.pdf: Attempting to reconstruct cross-reference table
hello.pdf: unable to find trailer dictionary while recovering damaged file

Where am I going wrong with this?

Many thanks in advance for any answers,
Cheers!

Answer 1

You should append a (syntactically correct) xref and trailer section to the end of the file. That means: each object in your PDF needs one line in the xref table, even if the byte offset isn't correctly stated. Then Ghostscript, pdftk or qpdf can re-establish a correct xref and render the file:

[...]
endobj
xref 
0 8 
0000000000 65535 f 
0000000010 00000 n 
0000000020 00000 n 
0000000030 00000 n 
0000000040 00000 n 
0000000050 00000 n 
0000000060 00000 n 
0000000070 00000 n 
trailer 
<</Size 8/Root 1 0 R>> 
startxref 
555 
%%EOF