Technical Q&A QA1529

Gathering all PostScript Printer Descriptions (PPDs)

Q: I'm trying to gather all available PPDs on the users system but calling PMCopyAvailablePPDs with kAllPPDDomains returns an error. How can I get a list of all PPDs on the user's system?

A: PMCopyAvailablePPDs on Mac OS X 10.4 and earlier may incorrectly return no results given the kAllPPDDomains domain if any of the searched paths does not exist. Typically the missing directory is ~/Library/Printers/ as this folder was not created for user accounts created on older versions of Mac OS X.

A simple work around is to call PMCopyAvailablePPDs with specific domains instead of using the kAllPPDDomains constant. Listing 1 demonstrates this method.

Listing 1: A simple replacement for PMCopyAvailablePPDs

// Appends the discovered PPDs to the given mutable array, or does nothing on error.
void AppendPPDs(PMPPDDomain domain, CFMutableArrayRef destination)
{
    CFArrayRef temp = NULL;
    OSStatus err = PMCopyAvailablePPDs(domain, &temp);
    if((err == noErr) && (temp != NULL))
    {
        CFArrayAppendArray(destination, temp, CFRangeMake(0, CFArrayGetCount(temp)));
        CFRelease(temp);
    }
}

// Calls AppendPPDs using all PPD domains to gather all available PPDs
CFArrayRef MyPMCopyAllAvailablePPDs()
{
    CFMutableArrayRef ppds = CFArrayCreateMutable(kCFAllocatorDefault, 0, &kCFTypeArrayCallBacks);
    AppendPPDs(kSystemPPDDomain, ppds);
    AppendPPDs(kLocalPPDDomain, ppds);
    AppendPPDs(kNetworkPPDDomain, ppds);
    AppendPPDs(kUserPPDDomain, ppds);
    AppendPPDs(kCUPSPPDDomain, ppds);
    return ppds;
}

Document Revision History

Posted: 2008-08-08