I have been toying with adding stuff to *.pdf files in cgi, graphs in particular.
PDFs created by PDFwriter or Distiller typically make extensive use of the
flate/deflate compression package in a way that, when reading a pdf directly, one has
to go through the process of decompression before much can be retrieved.
PDF files which include compression require transmission in binary mode and, for this
reason, Adobe recommends a comment line very early which contains at least one 8 bit
character to trigger ftp-binary in "automatic" programs. It also means that line ends
can be of any style.
Indexing into the files is based on the absolute character positions of objects. The
index begins at the trailing end and it's recommended that the file be read backwards.
A saving grace is that PDF files can be appended to without changing the preceding
bytes in any way.
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-> From the U S of A, the only socialist country that refuses to admit it. <-
