Description
The pdf_open() function opens
a new pdf document. The corresponding file has to be opened
with fopen() and the file descriptor passed
as argument file.
If you do not pass any parameters, the document will be created in memory
and outputed page by page either to stdout or to the web browser.
Note:
The return value is needed as the first parameter in all other
functions writing to the pdf document.
See also fopen(),
pdf_close().