IOS Judging Device type

-(nsstring*) devicestring{//need #import "Sys/utsname.h"    structUtsname SystemInfo; Uname (&systemInfo); NSString*devicestring =[NSString stringWithCString:systemInfo.machine encoding:nsutf8stringencoding]; //iphone    if([devicestring isequaltostring:@"iphone1,1"])return @"IPhone 1G"; if([devicestring isequaltostring:@"iphone1,2"])return @"IPhone 3G"; if([devicestring isequaltostring:@"iphone2,1"])return @"IPhone 3GS"; if([devicestring isequaltostring:@"iphone3,1"])return @"IPhone 4"; if([devicestring isequaltostring:@"iphone4,1"])return @"IPhone 4S"; if([devicestring isequaltostring:@"iphone5,2"])return @"IPhone 5"; if([devicestring isequaltostring:@"iphone5,3"])return @"IPhone 5C"; if([devicestring isequaltostring:@"iphone6,2"])return @"IPhone 5S"; if([devicestring isequaltostring:@"iphone3,2"])return @"Verizon IPhone 4"; //IPod    if([devicestring isequaltostring:@"ipod1,1"])return @"iPod Touch 1G"; if([devicestring isequaltostring:@"ipod2,1"])return @"iPod Touch 2G"; if([devicestring isequaltostring:@"ipod3,1"])return @"iPod Touch 3G"; if([devicestring isequaltostring:@"ipod4,1"])return @"iPod Touch 4G"; //IPad    if([devicestring isequaltostring:@"ipad1,1"])return @"IPad"; if([devicestring isequaltostring:@"ipad2,1"])return @"IPad 2 (WiFi)"; if([devicestring isequaltostring:@"ipad2,2"])return @"IPad 2 (GSM)"; if([devicestring isequaltostring:@"ipad2,3"])return @"IPad 2 (CDMA)"; if([devicestring isequaltostring:@"i386"])return @"Simulator"; if([devicestring isequaltostring:@"x86_64"])return @"Simulator"; //NSLog (@ "Note:unknown device type:%@", devicestring);    returndevicestring;}