xcode sysctlbyname 错误函数“sysctlbyname”的隐式声明在 C99 中无效
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/20578741/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
sysctlbyname error Implicit declaration of function 'sysctlbyname' is invalid in C99
提问by Malcolm
I am getting an error "Implicit declaration of function 'sysctlbyname' is invalid in C99" when i used this code. I used it before and it was fine so I don't know what happen.
当我使用此代码时，出现错误“函数‘sysctlbyname’的隐式声明在 C99 中无效”。我以前用过它，它很好，所以我不知道会发生什么。
I am currently developing for iOS7 devices only and using the latest ver of xcode 5 that is on the app store
我目前仅针对 iOS7 设备进行开发，并使用应用商店中最新版本的 xcode 5
UIDeviceHardware.m
UIDeviceHardware.m
@interface UIDeviceHardware : NSObject
- (NSString *) platform;
- (NSString *) platformString;
@end
UIDeviceHardware.m
UIDeviceHardware.m
- (NSString *) platform{
size_t size;
sysctlbyname("hw.machine", NULL, &size, NULL, 0);
char *machine = malloc(size);
sysctlbyname("hw.machine", machine, &size, NULL, 0);
NSString *platform = [NSString stringWithUTF8String:machine];
free(machine);
return platform;
}
- (NSString *) platformString{
NSString *platform = [self platform];
if ([platform isEqualToString:@"iPhone1,1"]) return @"iPhone 1G";
if ([platform isEqualToString:@"iPhone1,2"]) return @"iPhone 3G";
if ([platform isEqualToString:@"iPhone2,1"]) return @"iPhone 3GS";
if ([platform isEqualToString:@"iPhone3,1"]) return @"iPhone 4 (GSM)";
if ([platform isEqualToString:@"iPhone3,3"]) return @"iPhone 4 (CDMA)";
if ([platform isEqualToString:@"iPhone4,1"]) return @"iPhone 4S";
if ([platform isEqualToString:@"iPhone5,1"]) return @"iPhone 5 (GSM)";
if ([platform isEqualToString:@"iPhone5,2"]) return @"iPhone 5 (GSM+CDMA)";
if ([platform isEqualToString:@"iPhone5,3"]) return @"iPhone 5c (GSM)";
if ([platform isEqualToString:@"iPhone5,4"]) return @"iPhone 5c (GSM+CDMA)";
if ([platform isEqualToString:@"iPhone6,1"]) return @"iPhone 5s (GSM)";
if ([platform isEqualToString:@"iPhone6,2"]) return @"iPhone 5s (GSM+CDMA)";
if ([platform isEqualToString:@"iPhone7,1"]) return @"iPhone 6 GSM";
if ([platform isEqualToString:@"iPhone7,2"]) return @"iPhone 6 GSM+CDMA";
if ([platform isEqualToString:@"iPhone8,1"]) return @"iPhone 6+ GSM";
if ([platform isEqualToString:@"iPhone8,2"]) return @"iPhone 6+ Global";
if ([platform isEqualToString:@"iPod1,1"]) return @"iPod Touch 1G";
if ([platform isEqualToString:@"iPod2,1"]) return @"iPod Touch 2G";
if ([platform isEqualToString:@"iPod3,1"]) return @"iPod Touch 3G";
if ([platform isEqualToString:@"iPod4,1"]) return @"iPod Touch 4G";
if ([platform isEqualToString:@"iPod5,1"]) return @"iPod Touch 5G";
if ([platform isEqualToString:@"iPad1,1"]) return @"iPad";
if ([platform isEqualToString:@"iPad2,1"]) return @"iPad 2 (WiFi)";
if ([platform isEqualToString:@"iPad2,2"]) return @"iPad 2 (GSM)";
if ([platform isEqualToString:@"iPad2,3"]) return @"iPad 2 (CDMA)";
if ([platform isEqualToString:@"iPad2,4"]) return @"iPad 2 (WiFi)";
if ([platform isEqualToString:@"iPad2,5"]) return @"iPad Mini (WiFi)";
if ([platform isEqualToString:@"iPad2,6"]) return @"iPad Mini (GSM)";
if ([platform isEqualToString:@"iPad2,7"]) return @"iPad Mini (GSM+CDMA)";
if ([platform isEqualToString:@"iPad3,1"]) return @"iPad 3 (WiFi)";
if ([platform isEqualToString:@"iPad3,2"]) return @"iPad 3 (GSM+CDMA)";
if ([platform isEqualToString:@"iPad3,3"]) return @"iPad 3 (GSM)";
if ([platform isEqualToString:@"iPad3,4"]) return @"iPad 4 (WiFi)";
if ([platform isEqualToString:@"iPad3,5"]) return @"iPad 4 (GSM)";
if ([platform isEqualToString:@"iPad3,6"]) return @"iPad 4 (GSM+CDMA)";
if ([platform isEqualToString:@"iPad4,1"]) return @"iPad Air (WiFi)";
if ([platform isEqualToString:@"iPad4,2"]) return @"iPad Air (GSM)";
if ([platform isEqualToString:@"iPad4,4"]) return @"iPad Mini Retina (WiFi)";
if ([platform isEqualToString:@"iPad4,5"]) return @"iPad Mini Retina (GSM)";
if ([platform isEqualToString:@"i386"]) return @"Simulator";
if ([platform isEqualToString:@"x86_64"]) return @"Simulator";
return platform;
}
回答by dcorbatta
Maybe my answer is trivial, but, Did you include sys/sysctl.h?
也许我的回答是微不足道的，但是，你包括了sys/sysctl.h吗？
#import <sys/sysctl.h>
#import <sys/sysctl.h>
