1 files changed, 86 insertions, 0 deletions
diff --git a/Source/SPDataAdditions.m b/Source/SPDataAdditions.m
index 166288e5..ec91f55c 100644
--- a/Source/SPDataAdditions.m
+++ b/Source/SPDataAdditions.m
@@ -100,6 +100,92 @@ static char base64encodingTable[64] = {
 	return base64;
 }
 
+- (NSString *)dataToFormattedHexString
+/*
+ returns the hex representation of the given data
+ */
+{
+	unsigned i;
+	unsigned totalLength = [self length];
+	int bytesPerLine = 16;
+	NSMutableString *retVal = [NSMutableString string];
+	char *nodisplay = "\t\n\r\f";
+	
+	// get the length of the longest location
+	int longest = [(NSString *)[NSString stringWithFormat:@"%X", totalLength - ( totalLength % bytesPerLine )] length];
+	
+	for ( i = 0; i < totalLength; i += bytesPerLine ) {
+		int j;
+		NSMutableString *hex = [[NSMutableString alloc] initWithCapacity:(3 * bytesPerLine - 1)];
+		NSMutableString *location = [[NSMutableString alloc] initWithCapacity:(longest + 2)];
+		NSMutableString *chars = [[NSMutableString alloc] init];
+		unsigned char *buffer;
+		int buffLength = bytesPerLine;
+		
+		// add hex value of location
+		[location appendString:[NSString stringWithFormat:@"%X", i]];
+		
+		// pad it
+		while( longest > [location length] ) {
+			[location insertString:@"0" atIndex:0];
+		}
+		
+		// get the chars from the NSData obj
+		if ( i + buffLength >= totalLength ) {
+			buffLength = totalLength - i;
+		}
+		buffer = (unsigned char*) malloc( sizeof( unsigned char ) * buffLength );
+		NSRange range = { i, buffLength };
+		[self getBytes:buffer range:range];
+		
+		// build the hex string
+		for ( j = 0; j < buffLength; j++ ) {
+			unsigned char byte = *(buffer + j);
+			if ( byte < 16 ) {
+				[hex appendString:@"0"];
+			}
+			[hex appendString:[NSString stringWithFormat:@"%X", byte]];
+			[hex appendString:@" "];
+			
+			// if the char is undisplayable, replace it with "."
+			unsigned char current;
+			int count = 0;
+			while ( ( current = *(nodisplay + count++) ) > 0 ) {
+				if ( current == byte ) {
+					*(buffer + j) = '.';
+					break;
+				}
+			}
+		}
+		
+		// add padding to missing hex values.
+		for ( j = 0; j < bytesPerLine - buffLength; j++ ) {
+			[hex appendString:@"   "];
+		}
+		
+		// remove extra ghost characters
+		[chars appendString:[NSString stringWithCString:(char *)buffer]];
+		if ( [chars length] > bytesPerLine ) {
+			[chars deleteCharactersInRange:NSMakeRange( bytesPerLine, [chars length] - bytesPerLine )];
+		}
+		
+		// build line
+		[retVal appendString:location];
+		[retVal appendString:@"  "];
+		[retVal appendString:hex];
+		[retVal appendString:@" "];
+		[retVal appendString:chars];
+		[retVal appendString:@"\n"];
+		
+		// clean up
+		[hex release];
+		[chars release];
+		[location release];
+		free( buffer );
+	}
+	
+	return retVal;
+}
 
 
 @end