On Nov 25, 2011, at 7:07 PM, Glenn L. Austin wrote: > On Nov 25, 2011, at 2:56 PM, Koen van der Drift wrote: > >> On Nov 25, 2011, at 5:44 PM, Scott Ribe wrote: >> >>> As another response suggested, what's wrong with ntohl??? >> >> I implemented that function based on some code I found online, but got very >> weird results, which is why I asked here. My knowledge on these esoteric >> functions apparently isn't up to par :) >> >> As long as I end up with an array of x,y values, I really don't care how I >> get there. Eventually they will need to end up in an NSArray for further >> processing though. > > That function is already implemented on every machine that support networking > -- including Mac OS X. You don't need to implement it yourself -- just > #include <arpa/inet.h> > > Do a man ntohl for more info.
I read that but am still confused :( Here is what I am doing, I read an NSString from the raw data, an xml file using NSXMLParser. This works ok. Then I convert that to an NSData object, and perform base64 decoding (using http://cocoawithlove.com/2009/06/base64-encoding-options-on-mac-and.html): NSData *data = [string dataUsingEncoding:NSASCIIStringEncoding]; NSString *base64String = [data base64EncodedString]; NSData * base64DecodedData = [NSData dataFromBase64String:base64String]; I then retrieve chunks of 32 bytes as follows: NSRange range = {n, 32}; NSData *chunk = [base64DecodedData subdataWithRange:range]; But I am struggling with how to use this with ntohl, similar to the code I am trying to implement: for (n = 0 ; n < (2 * count) ; n++) { ((u_int32_t *) result)[n] = ntohl((u_int32_t) ((u_int32_t *) dataToConvert)[n]); } Any help appreciated. I am happy to send the raw string off-list if anyone wants to give it a try. The end results should give pairs of floats: 300.066772460938 1201.86157226562 301.141448974609 45845.18359375 301.215972900391 1430.0322265625 etc Thanks, - Koen. _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
