NSString to char* with greek characters - ios

Question

I am using the following code to store the data of a string in a char*.
NSString *hotelName = [components[2] stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
hotelInfo->hotelName = malloc(sizeof(char) * hotelName.length + 1);
strncpy(hotelInfo->hotelName, [hotelName UTF8String], hotelName.length + 1);
NSLog(#"HOTEL NAME: %s",hotelInfo->hotelName);
The problem is with the Greek characters that are printed strangely. I have also tried to use another encoding (e.g NSWindowsCP1253StringEncoding -it crashes- )
I tried even that:
hotelInfo->hotelName = (const char *)[hotelName cStringUsingEncoding:NSUnicodeStringEncoding];
but it also produces strange characters.
What do I miss?
EDIT:
After some suggestions I tried the following:
if ([hotelName canBeConvertedToEncoding:NSWindowsCP1253StringEncoding]){
const char *cHotelName = (const char *)[hotelName cStringUsingEncoding:NSWindowsCP1253StringEncoding];
int bufSize = strlen(cHotelName) + 1;
if (bufSize >0 ){
hotelInfo->hotelName = malloc(sizeof(char) * bufSize);
strncpy(hotelInfo->hotelName, [hotelName UTF8String], bufSize);
NSLog(#"HOTEL NAME: %s",hotelInfo->hotelName);
}
}else{
NSLog(#"String cannot be encoded! Sorry! %#",hotelName);
for (NSInteger charIdx=0; charIdx<hotelName.length; charIdx++){
// Do something with character at index charIdx, for example:
char x[hotelName.length];
NSLog(#"%C", [hotelName characterAtIndex:charIdx]);
x[charIdx] = [hotelName characterAtIndex:charIdx];
NSLog(#"%s", x);
if (charIdx == hotelName.length - 1)
hotelInfo->hotelName = x;
}
NSLog(#"HOTEL NAME: %s",hotelInfo->hotelName);
}
But still nothing!

Answer 1

First of all, it is not guaranteed that any NSString can be represented as a C character array (so-called C-String). The reason is that there is just a limited set of characters available. You should check if the string can be converted (by calling canBeConvertedToEncoding:).
Secondly, when using the malloc and strncpy functions, they rely on the length of the C-String, not on the length of the NSString. So you should first get the C-String from the NSString, then get it's length (strlen), and use this value to the function calls:
const char *cHotelName = (const char *)[hotelName cStringUsingEncoding:NSWindowsCP1253StringEncoding];
int bufSize = strlen(cHotelName) + 1;
hotelInfo->hotelName = malloc(sizeof(char) * bufSize);
strncpy(hotelInfo->hotelName, cHotelName, bufSize);