Swift3.0 调用C函数

2018-08-17

一般情况下Swit要想调用obj-c,c或c++代码必须通过obj-c以及桥接文件才可以办到,但是使用@_silgen_name,可以对于某些简单的代码,直接跳过桥接文件和.h头文件与C代码交互。

创建.c文件

#include <stdio.h>
int add(int i, int j){
    return i + j;
}

int mul(int i, int times){
    return i * times;
}

创建.swift文件,引用.c文件函数

// 在全局作用域下进行声明
// swift 2.2使用关键字@asmname
import Foundation
@_silen_name("add") func c_add(_ num1: Int, _ num2: Int) -> Int
@_silgen_name("mul") func c_mul(_ num: Int, _ times: Int) -> Int

// 调用函数
print(c_add(80, 23))
print(c_mul(3, 10))

// 结果
103
30

例：
Swift 引用 “@_silgen_name”

@_silgen_name(“yudpsocket_server”) func c_yudpsocketserver( host:UnsafePointer,port:Int32) -> Int32

@_silgen_name(“yudpsocket_recive”) func c_yudpsocketrecive( fd:Int32,buff:UnsafePointer,len:Int32,ip:UnsafePointer,port:UnsafePointer) -> Int32

@_silgen_name(“yudpsocket_close”) func c_yudpsocketclose( fd:Int32) -> Int32

@_silgen_name(“yudpsocket_client”) func c_yudpsocket_client() -> Int32

@_silgen_name(“yudpsocket_get_server_ip”) func c_yudpsocket_get_serverip( host:UnsafePointer,ip:UnsafePointer) -> Int32

@_silgen_name(“yudpsocket_sentto”) func c_yudpsocketsentto( fd:Int32,buff:UnsafePointer,len:Int32,ip:UnsafePointer,port:Int32) -> Int32

@_silgen_name(“enable_broadcast”) func c_enablebroadcast( fd:Int32)

///////yudpsocket.c

#include

#define yudpsocket_buff_len 8192

//return socket fd

int yudpsocket_server(const char *address, int port) {

//create socket

int socketfd=socket(AF_INET, SOCK_DGRAM, 0);

int reuseon = 1;

int r = -1;

//bind

struct sockaddr_in serv_addr;

memset( &serv_addr, ‘\0’, sizeof(serv_addr));

serv_addr.sin_len = sizeof(struct sockaddr_in);

serv_addr.sin_family = AF_INET;

if (address == NULL || strlen(address) == 0 || strcmp(address, “255.255.255.255”) == 0) {

r = setsockopt(socketfd, SOL_SOCKET, SO_BROADCAST, &reuseon, sizeof(reuseon));

serv_addr.sin_port = htons(port);

serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);

} else {

r = setsockopt(socketfd, SOL_SOCKET, SO_REUSEADDR, &reuseon, sizeof(reuseon));

serv_addr.sin_addr.s_addr = inet_addr(address);

serv_addr.sin_port = htons(port);

}

if (r == -1) {

return -1;

}

r = bind(socketfd, (struct sockaddr ) &serv_addr, sizeof(serv_addr));

if (r == 0) {

return socketfd;

} else {

return -1;

}

}

int yudpsocket_recive(int socket_fd, char outdata, int expted_len, char remoteip, int remoteport) {

struct sockaddr_in cli_addr;

socklen_t clilen = sizeof(cli_addr);

memset(&cli_addr, 0x0, sizeof(struct sockaddr_in));

int len = (int)recvfrom(socket_fd, outdata, expted_len, 0, (struct sockaddr )&cli_addr, &clilen);

char clientip = inet_ntoa(cli_addr.sin_addr);

memcpy(remoteip, clientip, strlen(clientip));

remoteport = cli_addr.sin_port;

return len;

}

int yudpsocket_close(int socket_fd) {

return close(socket_fd);

}

//return socket fd

int yudpsocket_client() {

//create socket

int socketfd = socket(AF_INET, SOCK_DGRAM, 0);

int reuseon = 1;

setsockopt(socketfd, SOL_SOCKET, SO_REUSEADDR, &reuseon, sizeof(reuseon));

return socketfd;

}

//enable broadcast

void enable_broadcast(int socket_fd) {

int reuseon = 1;

setsockopt(socket_fd, SOL_SOCKET, SO_BROADCAST, &reuseon, sizeof(reuseon));

}

int yudpsocket_get_server_ip(char host, char ip) {

struct hostent hp;

struct sockaddr_in address;

hp = gethostbyname(host);

if (hp == NULL) {

return -1;

}

bcopy((char )hp->h_addr, (char )&address.sin_addr, hp->h_length);

char clientip = inet_ntoa(address.sin_addr);

memcpy(ip, clientip, strlen(clientip));

return 0;

}

//send message to address and port

int yudpsocket_sentto(int socket_fd, char msg, int len, char toaddr, int topotr) {

struct sockaddr_in address;

socklen_t addrlen = sizeof(address);

memset(&address, 0x0, sizeof(struct sockaddr_in));

address.sin_family = AF_INET;

address.sin_port = htons(topotr);

address.sin_addr.s_addr = inet_addr(toaddr);

int sendlen = (int)sendto(socket_fd, msg, len, 0, (struct sockaddr )&address, addrlen);

return sendlen;

}