Question

I’ve successfully set up a small XZ compressor which returns a std::string that contains the compressed output. To process the result I need to “convert” the std::string to a NSString. Unfortunately there are (encoding?) problems:

Even though “abc” is not a good example it shows the difficulty pretty good:

NSString *text = [_text string]; // Length is 3

std::string content = xz_compress([text UTF8String]); // Length is 60

NSString *convertedContent = [NSString stringWithCString:content.c_str() encoding:NSUTF8StringEncoding];

// convertedContent is (null) and 0 characters long

Using NSUnicodeStringEncoding makes the NSString at least 2 characters long but they don’t match the ones from std::string.

My questions:

• Is this way possible / the preferable way (already unsure about that)?
• If so: What encoding do I need to use?

Thanks in advance!

Paul

Answer 1

I assume that xz_compress output is binary data. So, why don’t you try and use NSData dataWithBytes:length: method? Possibly you could also try with string::data() instead of string::c_str for the same reason:

NSData* convertedContent = [NSData dataWithBytes:content.data() length:content.length()];