Re: Some Questions about Parsing data from PostScript file

Regarding:

My printer, it is a Laser engraver, which can accept PCL raster command and HPGL vector command.
1.Because that, I had implemented a raster driver which serves bitmap image file only. But for other hybrid files, like .cdr or .ai, which include bitmap and vector data, I also want to implement a driver to filtering PostScript file to parsing raster and vector data. Is it possible?

It is possible but because of the way that cups evaluates which filters to run, for a given input type of data like PDF that is the typical type of input to the cups filter chain, the same set of filters will run, regardless of the content of the PDF data. Since most applications generate PDF data through the printing system regardless of the original content they are printing, I don't think you will achieve the effect you want.

2.I had successfully let the bitmap image file to output to my printer. And the filter path I added in PPD file is:
*cupsFilter: "application/vnd.cups-raster 0 rastertoMyprinter"

If I want to add the parsing PostScript driver to PPD file and let it and rastertoMyprinter driver exist at the same. Is below filter path correct?
*cupsFilter: "application/vnd.cups-postscript 0 posttoMyprinter"

Looks correct. My comments above are relevant to what you are trying to do.

3.Any sample is good for me to achieve parsing PostScript file and get raster and vector data?
(At least, I can separate this two kind of data from PostScript.)

As a general rule, Apple discourages this approach but that decision will be up to you. Our recommendation is to handle the cups-raster format and send that to your printer. If you insist on getting vector data, text, and images rather than rendered bits, I think a potentially better approach than parsing PostScript data would be to instead accept PDF data since that is a more readily parseable form. Others on the mailing list are probably more likely than me to suggest where to find example code for doing this. It isn't a simple thing to do properly.

References:
	>Some Questions about Parsing data from PostScript file (From: Henry Lai <email@hidden>)