C语言发post请求数据程序， 工作需要，网上查资料N篇，作为半路出家学编程的，走过了N个坑，终于完成以下的测试程序。
使用了curl的库, 这样无论在windows或者在linux都可以使用.
win下的编程环境是TDM-GCC-64, 怎样安装，也是另一个话题。需要这个的请自行上网查询怎样安装.
linux 下是gcc环境，最好先安装curl开发包，目的就是需要curl.h等文件, 怎样安装，也是另一个话题。
废话不说，以下是正式程序.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <curl/curl.h>
struct string {
char *ptr;
size_t len;
};
void init_string(struct string *s) {
s->len = 0;
s->ptr = malloc(s->len + 1);
if (s->ptr == NULL) {
fprintf(stderr, "malloc() failed\n");
exit(EXIT_FAILURE);
}
s->ptr[0] = '\0';
}
size_t writefunc(void *ptr, size_t size, size_t nmemb, struct string *s)
{
size_t new_len = s->len + size * nmemb;
s->ptr = realloc(s->ptr, new_len + 1);
if (s->ptr == NULL) {
fprintf(stderr, "realloc() failed\n");
exit(EXIT_FAILURE);
}
memcpy(s->ptr + s->len, ptr, size*nmemb);
s->ptr[new_len] = '\0';
s->len = new_len;
return size * nmemb;
}
CURLcode curl_post_req(char *url, char *postParams,struct curl_slist *headers, char *response)
{
CURL *curl;
curl = curl_easy_init(); //初始化
// curl返回值
CURLcode res;
if (curl)
{
struct string s;
init_string(&s);
curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
//curl_easy_setopt(curl, CURLOPT_URL, "http://httpbin.org/post");
curl_easy_setopt(curl, CURLOPT_URL, url);
curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, writefunc);
curl_easy_setopt(curl, CURLOPT_WRITEDATA, &s);
curl_easy_setopt(curl, CURLOPT_POST, 1);//设置CURLOPT_POST之后必须带有POST数据
curl_easy_setopt(curl, CURLOPT_POSTFIELDS, postParams);
//不接收响应头数据0代表不接收 1代表接收
curl_easy_setopt(curl, CURLOPT_HEADER, 0);
curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
//CURLOPT_VERBOSE的值为1时，会显示详细的调试信息
curl_easy_setopt(curl, CURLOPT_VERBOSE, 0);
curl_easy_setopt(curl, CURLOPT_READFUNCTION, NULL);
curl_easy_setopt(curl, CURLOPT_NOSIGNAL, 1);
//设置超时时间，以秒来计算 CURLOPT_CONNECTTIMEOUT是连接超时
curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT, 10);
curl_easy_setopt(curl, CURLOPT_TIMEOUT, 10);
// https ssl 时需要用到，如果是 http 可以注释掉
curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0L);
curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0L);
res = curl_easy_perform(curl);
//printf(" =>%s=>=>\n", s.ptr);
sprintf(response," =>%s\n", s.ptr);
free(s.ptr);
curl_slist_free_all(headers);
};
curl_easy_cleanup(curl);
return res;
}
int main(int argc, const char *argv[])
{
// http 请求头, 构造
printf(" start...\n");
struct curl_slist *headers1 = NULL;
headers1 = curl_slist_append(headers1, "User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; Trident/7.0; rv:11.0) like Gecko");
headers1 = curl_slist_append(headers1, "Content-Type:application/x-www-form-urlencoded; charset=UTF-8");
char url_post0[100] = "https://www.lpfrx.com/";
// 查找的字符串 ： delphi
char paramsLogin0[100] = "s=delphi";
char resPost0[40960] = "";
CURLcode res3 = curl_post_req(url_post0, paramsLogin0, headers1,resPost0);
if (res3 == CURLE_OK)
{
printf("data: %s" ,resPost0);
}
printf(" end...\n");
return 0;
}
// win 下cmd下运行乱码，请先执行 chcp 65001 转成 utf8. 默认是chcp 936
// win: 运行目录下需要zlib.dll libcurl.dll
// curl-Library 是我自己的目录，放在当前的程序目录下，win下的curl.h 也是需要自己去找，如果有python编程环境的话，也安装了curl库的话，应该可能会有curl.h的库路径
// win: gcc -o curlpostlpfrx curlpost_lpfrx.c -I ./curl-Library/include -L ./curl-Library/lib -lcurl
//linux: gcc -o curlpostlpfrx curlpost_lpfrx.c -lcurl
