// GetPrinters gets all CUPS printers found on the CUPS server.
func (c *CUPS) GetPrinters() ([]lib.Printer, error) {
pa := C.newArrayOfStrings(C.int(len(c.printerAttributes)))
defer C.freeStringArrayAndStrings(pa, C.int(len(c.printerAttributes)))
for i, a := range c.printerAttributes {
C.setStringArrayValue(pa, C.int(i), C.CString(a))
}
response, err := c.cc.getPrinters(pa, C.int(len(c.printerAttributes)))
if err != nil {
return nil, err
}
// cupsDoRequest() returns ipp_t pointer which needs explicit free.
defer C.ippDelete(response)
if C.ippGetStatusCode(response) == C.IPP_STATUS_ERROR_NOT_FOUND {
// Normal error when there are no printers.
return make([]lib.Printer, 0), nil
}
printers := c.responseToPrinters(response)
for i := range printers {
printers[i].GCPVersion = lib.GCPAPIVersion
printers[i].ConnectorVersion = lib.ShortName
printers[i].SetupURL = lib.ConnectorHomeURL
printers[i].SupportURL = lib.ConnectorHomeURL
printers[i].UpdateURL = lib.ConnectorHomeURL
}
printers = c.addDescriptionToPrinters(printers)
return printers, nil
}
// doRequest calls cupsDoRequest().
func (cc *cupsCore) doRequest(request *C.ipp_t, acceptableStatusCodes []C.ipp_status_t) (*C.ipp_t, error) {
http, err := cc.connect()
if err != nil {
return nil, err
}
defer cc.disconnect(http)
if C.ippValidateAttributes(request) != 1 {
return nil, fmt.Errorf("Bad IPP request: %s", C.GoString(C.cupsLastErrorString()))
}
response := C.cupsDoRequest(http, request, C.POST_RESOURCE)
if response == nil {
return nil, fmt.Errorf("cupsDoRequest failed: %d %s", int(C.cupsLastError()), C.GoString(C.cupsLastErrorString()))
}
statusCode := C.ippGetStatusCode(response)
for _, sc := range acceptableStatusCodes {
if statusCode == sc {
return response, nil
}
}
return nil, fmt.Errorf("IPP status code %d", int(statusCode))
}