在翔云平台注册并购买人脸识别服务，将key和secret复制过来放入代码中，通过https协议与翔云建立连接
libcurl库的安装
1、库下载https://github.com/curl/curl/releases/tag/curl-7_71_1
下载curl-7.71.1.tar.gz
2、进行解压

tar xvf curl-7.71.1.tar.gz

3、需要安装可支持https的openLLS
下载openssl-1.1.1a.tar.gz（我传到我的资源里，可到资源里免费下载）
具体步凑如下

		tar -vxf openssl-1.1.1a.tar.gz

	cd openssl-1.1.1a

	config

	make

	make install

4、
安装openSSL成功继续安装libcurl

./configure --prefix=$PWD/_install --with-ssl	//指定安装路径

5、

make	//编译

make install	//安装

6、安装成功后用如下指令编译人脸识别代码，需要提前将比对图片xx.jpg格式的图片放到文件夹下

gcc demo3.c -I ./curl-7.71.1/_install/include/ -L ./curl-7.71.1/_install/lib/ -lcurl

7、./a.out运行，运行结果如下

人脸识别代码，demo.c

#include <stdio.h>
#include <curl/curl.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>


#define true 1
#define false 0

typedef unsigned int bool;

char readBuf[1024] = {'\0'};	//存放返回的字符串

size_t readData( void *ptr, size_t size, size_t nmemb, void *stream)
{
	strncpy(readBuf,ptr,1024);	//将返回的字符串读到readBuf里
}


/*获取图片base64编码值*/
char *getPicBase64FromFile(char *filePath)
{
	char *bufPic;
	char cmd[128] = {'\0'};
	sprintf(cmd,"base64 %s > tmpFile",filePath);	//获取图片base64编码值并将该字符串拼接存放到tmpFile中
	system(cmd);

	int fd = open("./tmpFile",O_RDWR);	//打开tmpFile文件
	int filelen = lseek(fd,0,SEEK_END);	//算出该文件的大小
	lseek(fd,0,SEEK_SET);	//将光标定位到文件头
	bufPic = (char *)malloc(filelen+2);	//开辟空间存放图片base64编码值
	memset(bufPic,'\0',filelen+2);	//初始化
	read(fd,bufPic,filelen);	//将图片编码值读到bufPic中
	close(fd);
	system("rm -f tmpFile");	//删除内容供下次函数调用

	return bufPic;	//返回base64编码值
}

bool postUrl()
{
	CURL *curl;
	CURLcode res;
	char *postString;	//存放拼接的字符串


	char *key = "5XkKjQc1k99DVQ67Gqxxxx";
	char *secret = "44d5776c5dea4648bf3f9a7d2exxxxx";
	int typeId = 21;
	char *format = "xml";

	char *bufPic1 = getPicBase64FromFile("./huyu1.jpg");
	char *bufPic2 = getPicBase64FromFile("./huyu2.jpg");

	int len = strlen(key)+strlen(secret)+strlen(bufPic1)+strlen(bufPic2)+124;

	postString = (char *)malloc(len);

	sprintf(postString,"&img1=%s&img2=%s&key=%s&secret=%s&typeId=%d&format=%s",bufPic1,bufPic2,key,secret,21,format);
	//字符串拼接

	curl = curl_easy_init();
	if (curl)
	{
		curl_easy_setopt(curl, CURLOPT_POSTFIELDS, postString);    // 指定post内容
		curl_easy_setopt(curl, CURLOPT_URL, "https://netocr.com/api/faceliu.do");   // 指定url
		curl_easy_setopt(curl,CURLOPT_WRITEFUNCTION,readData);	//readData回调函数处理返回的数据

		res = curl_easy_perform(curl);

		printf("ok:%d\n",res);

		if(strstr(readBuf,"是") != NULL){	/*将返回的字符串与“是”进行比对，若不等于NULL，则为同一个人*/
			printf("the same Person\n");
		}else{
			printf("diffrent Person\n");

		}
		curl_easy_cleanup(curl);



	}
	return true;
}
int main(void)
{
	postUrl();

}