标签：des http 使用 os io for ar cti
libcurl有两个接口
easy接口 同步、高效 前缀curl_easy。
multi接口 异步 前缀curl_multi。multi使用单线程
easy使用范例
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <curl/curl.h>
//回调
static size_t write_data(void *ptr, size_t size, size_t nmemb, void *stream)
{
int written = fwrite(ptr, size, nmemb, (FILE *)stream);
return written;
}
int main(void)
{
CURL *curl_handle;
static const char *headerfilename = "head.out";
FILE *headerfile;
static const char *bodyfilename = "body.out";
FILE *bodyfile;
curl_global_init(CURL_GLOBAL_ALL);
/* init the curl session */
curl_handle = curl_easy_init();
/* set URL to get */
curl_easy_setopt(curl_handle, CURLOPT_URL, "http://example.com");
/* no progress meter please */
curl_easy_setopt(curl_handle, CURLOPT_NOPROGRESS, 1L);
/* send all data to this function */
curl_easy_setopt(curl_handle, CURLOPT_WRITEFUNCTION, write_data);
/* open the files */
headerfile = fopen(headerfilename,"wb");
if (headerfile == NULL) {
curl_easy_cleanup(curl_handle);
return -1;
}
bodyfile = fopen(bodyfilename,"wb");
if (bodyfile == NULL) {
curl_easy_cleanup(curl_handle);
return -1;
}
/* we want the headers be written to this file handle */
curl_easy_setopt(curl_handle, CURLOPT_WRITEHEADER, headerfile);
/* we want the body be written to this file handle instead of stdout */
curl_easy_setopt(curl_handle, CURLOPT_WRITEDATA, bodyfile);
/* get it! */
curl_easy_perform(curl_handle);
/* close the header file */
fclose(headerfile);
/* close the body file */
fclose(bodyfile);
/* cleanup curl stuff */
curl_easy_cleanup(curl_handle);
return 0;
}
multi使用范例
#include <stdio.h>
#include <string.h>
#include <sys/time.h>
#include <curl/curl.h>
int main(void)
{
CURL *curl;
CURLM *multi_handle;
int still_running;
struct curl_httppost *formpost=NULL;
struct curl_httppost *lastptr=NULL;
struct curl_slist *headerlist=NULL;
static const char buf[] = "Expect:";
/* Fill in the file upload field. This makes libcurl load data from
the given file name when curl_easy_perform() is called. */
curl_formadd(&formpost,
&lastptr,
CURLFORM_COPYNAME, "sendfile",
CURLFORM_FILE, "postit2.c",
CURLFORM_END);
/* Fill in the filename field */
curl_formadd(&formpost,
&lastptr,
CURLFORM_COPYNAME, "filename",
CURLFORM_COPYCONTENTS, "postit2.c",
CURLFORM_END);
/* Fill in the submit field too, even if this is rarely needed */
curl_formadd(&formpost,
&lastptr,
CURLFORM_COPYNAME, "submit",
CURLFORM_COPYCONTENTS, "send",
CURLFORM_END);
curl = curl_easy_init();
multi_handle = curl_multi_init();
/* initalize custom header list (stating that Expect: 100-continue is not
wanted */
headerlist = curl_slist_append(headerlist, buf);
if(curl && multi_handle) {
/* what URL that receives this POST */
curl_easy_setopt(curl, CURLOPT_URL, "http://www.example.com/upload.cgi");
curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headerlist);
curl_easy_setopt(curl, CURLOPT_HTTPPOST, formpost);
curl_multi_add_handle(multi_handle, curl);
curl_multi_perform(multi_handle, &still_running);
do {
struct timeval timeout;
int rc; /* select() return code */
fd_set fdread;
fd_set fdwrite;
fd_set fdexcep;
int maxfd = -1;
long curl_timeo = -1;
FD_ZERO(&fdread);
FD_ZERO(&fdwrite);
FD_ZERO(&fdexcep);
/* set a suitable timeout to play around with */
timeout.tv_sec = 1;
timeout.tv_usec = 0;
curl_multi_timeout(multi_handle, &curl_timeo);
if(curl_timeo >= 0) {
timeout.tv_sec = curl_timeo / 1000;
if(timeout.tv_sec > 1)
timeout.tv_sec = 1;
else
timeout.tv_usec = (curl_timeo % 1000) * 1000;
}
/* get file descriptors from the transfers */
curl_multi_fdset(multi_handle, &fdread, &fdwrite, &fdexcep, &maxfd);
/* In a real-world program you OF COURSE check the return code of the
function calls. On success, the value of maxfd is guaranteed to be
greater or equal than -1. We call select(maxfd + 1, ...), specially in
case of (maxfd == -1), we call select(0, ...), which is basically equal
to sleep. */
rc = select(maxfd+1, &fdread, &fdwrite, &fdexcep, &timeout);
switch(rc) {
case -1:
/* select error */
break;
case 0:
default:
/* timeout or readable/writable sockets */
printf("perform!\n");
curl_multi_perform(multi_handle, &still_running);
printf("running: %d!\n", still_running);
break;
}
} while(still_running);
curl_multi_cleanup(multi_handle);
/* always cleanup */
curl_easy_cleanup(curl);
/* then cleanup the formpost chain */
curl_formfree(formpost);
/* free slist */
curl_slist_free_all (headerlist);
}
return 0;
}
标签：des http 使用 os io for ar cti
原文地址：http://www.cnblogs.com/xhmf/p/3891464.html
