当使用NSURLRequest
请求主机名时,是否可以获取响应来自的服务器的IP地址?
NSURL
方法:
- (NSString *)host;
仅返回主机名,我没有看到从任何其他NSURL
方法中获取IP地址的方法。
也许在初始化NSURLRequest
之前执行主机查找的方法?
当使用NSURLRequest
请求主机名时,是否可以获取响应来自的服务器的IP地址?
NSURL
方法:
- (NSString *)host;
仅返回主机名,我没有看到从任何其他NSURL
方法中获取IP地址的方法。
也许在初始化NSURLRequest
之前执行主机查找的方法?
示例代码
struct hostent *hostentry;
hostentry = gethostbyname("google.com");
char * ipbuf;
ipbuf = inet_ntoa(*((struct in_addr *)hostentry->h_addr_list[0]));
printf("%s",ipbuf);
我有一个关于如何在Unix / Linux中从主机名获取IP的问题,但是发现这个问题是在不同的环境下提出的,我想如果我错了,请纠正我。
由于已经问过了这个问题,所以我担心避免被stackoverflow团队标记为重复提问。
问题:如何在Unix / Linux中从主机名获取IP?
答案:存在两个命令:
例如:
ping -s google.co.in
PING google.co.in: 56 data bytes
64 bytes from dfw06s48-in-f3.1e100.net (216.58.194.99): icmp_seq=0. time=2.477 ms
64 bytes from dfw06s48-in-f3.1e100.net (216.58.194.99): icmp_seq=1. time=1.415 ms
64 bytes from dfw06s48-in-f3.1e100.net (216.58.194.99): icmp_seq=2. time=1.712 ms
例如:
nslookup google.co.in
Server: 155.179.59.249
Address: 155.179.59.249#53
Non-authoritative answer:
Name: google.co.in
Address: 216.58.194.99
#import <arpa/inet.h>
- (BOOL)resolveHost:(NSString *)hostname {
Boolean result;
CFHostRef hostRef;
CFArrayRef addresses;
NSString *ipAddress = nil;
hostRef = CFHostCreateWithName(kCFAllocatorDefault, (__bridge
CFStringRef)hostname);
CFStreamError *error = NULL;
if (hostRef) {
result = CFHostStartInfoResolution(hostRef, kCFHostAddresses, error);
if (result) {
addresses = CFHostGetAddressing(hostRef, &result);
}
}
if (result) {
CFIndex index = 0;
CFDataRef ref = (CFDataRef) CFArrayGetValueAtIndex(addresses, index);
int port=0;
struct sockaddr *addressGeneric;
NSData *myData = (__bridge NSData *)ref;
addressGeneric = (struct sockaddr *)[myData bytes];
switch (addressGeneric->sa_family) {
case AF_INET: {
struct sockaddr_in *ip4;
char dest[INET_ADDRSTRLEN];
ip4 = (struct sockaddr_in *)[myData bytes];
port = ntohs(ip4->sin_port);
ipAddress = [NSString stringWithFormat:@"%s", inet_ntop(AF_INET, &ip4->sin_addr, dest, sizeof dest)];
}
break;
case AF_INET6: {
struct sockaddr_in6 *ip6;
char dest[INET6_ADDRSTRLEN];
ip6 = (struct sockaddr_in6 *)[myData bytes];
port = ntohs(ip6->sin6_port);
ipAddress = [NSString stringWithFormat:@"%s", inet_ntop(AF_INET6, &ip6->sin6_addr, dest, sizeof dest)];
}
break;
default:
ipAddress = nil;
break;
}
}
NSLog(@"%@", ipAddress);
if (ipAddress) {
return YES;
} else {
return NO;
}
}
[self resolveHost:@"google.com"]