c語言http的http_get和http_post的實現

http.c

#include <stdio.h>
#include <stdlib.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <string.h>
#include <unistd.h>

#include "http.h"

#define BUFFER_SIZE 1024
#define HTTP_POST "POST /%s HTTP/1.1\r\nHOST: %s:%d\r\nAccept: */*\r\n"\
	"Content-Type:application/x-www-form-urlencoded\r\nContent-Length:\
	%d\r\n\r\n%s"

#define HTTP_GET "GET /%s HTTP/1.1\r\nHOST: %s:%d\r\nAccept: */*\r\n\r\n"

static int http_tcpclient_create(const char *host, int port)
{
	struct hostent *he;
	struct sockaddr_in server_addr; 
	int socket_fd;

	if ((he = gethostbyname(host)) == NULL) {
		return -1;
	}

	server_addr.sin_family = AF_INET;
	server_addr.sin_port = htons(port);
	server_addr.sin_addr = *((struct in_addr *)he->h_addr);

	if ((socket_fd = socket(AF_INET,SOCK_STREAM,0)) == (-1)) {
		return -1;
	}

	if (connect(socket_fd,
		(struct sockaddr *)&server_addr,
		sizeof(struct sockaddr)) == -1) {
		return -1;
	}

	return socket_fd;
}

static void http_tcpclient_close(int socket)
{
	close(socket);
}

static int http_parse_url(const char *url, char *host, char *file, int *port)
{
	char *ptr1, *ptr2;
	int len = 0;
	if (!url || !host || !file || !port) {
		return -1;
	}

	ptr1 = (char *)url;

	if (!strncmp(ptr1, "http://", strlen("http://"))) {
		ptr1 += strlen("http://");
	} else {
		return -1;
	}

	ptr2 = strchr(ptr1, '/');
	if (ptr2) {
		len = strlen(ptr1) - strlen(ptr2);
		memcpy(host, ptr1, len);
		host[len] = '\0';
		if (*(ptr2 + 1)) {
			memcpy(file,ptr2 + 1,strlen(ptr2) - 1 );
			file[strlen(ptr2) - 1] = '\0';
		}
	} else {
		memcpy(host,ptr1,strlen(ptr1));
		host[strlen(ptr1)] = '\0';
	}
	ptr1 = strchr(host,':');
	if (ptr1) {
		*ptr1++ = '\0';
		*port = atoi(ptr1);
	} else {
		*port = MY_HTTP_DEFAULT_PORT;
	}

	return 0;
}

static int http_tcpclient_recv(int socket, char *lpbuff)
{
	int recvnum = 0;

	recvnum = recv(socket, lpbuff, BUFFER_SIZE*4, 0);

	return recvnum;
}

static int http_tcpclient_send(int socket, char *buff, int size)
{
	int sent=0, tmpres=0;

	while (sent < size) {
		tmpres = send(socket, buff+sent, size-sent, 0);
		if(tmpres == -1){
			return -1;
		}
		sent += tmpres;
	}
	return sent;
}

static char *http_parse_result(const char*lpbuf)
{
	char *ptmp = NULL; 
	char *response = NULL;
	ptmp = (char*)strstr(lpbuf, "HTTP/1.1");
	if (!ptmp) {
		printf("http/1.1 not faind\n");
		return NULL;
	}
	if (atoi(ptmp + 9) != 200){
		printf("result:\n%s\n", lpbuf);
		return NULL;
	}

	ptmp = (char *)strstr(lpbuf, "\r\n\r\n");
	if (!ptmp) {
		printf("ptmp is NULL\n");
		return NULL;
	}
	response = (char *)malloc(strlen(ptmp) + 1);
	if (!response) {
		printf("malloc failed \n");
		return NULL;
	}
	strcpy(response, ptmp+4);
	return response;
}

char *http_post(const char *url, const char *post_str)
{

	int socket_fd = -1;
	char lpbuf[BUFFER_SIZE*4] = {'\0'};
	char host_addr[BUFFER_SIZE] = {'\0'};
	char file[BUFFER_SIZE] = {'\0'};
	int port = 0;

	if (!url || !post_str) {
		printf("failed!\n");
		return NULL;
	}

	if (http_parse_url(url, host_addr, file, &port)) {
		printf("http_parse_url failed!\n");
		return NULL;
	}

	socket_fd = http_tcpclient_create(host_addr, port);
	if (socket_fd < 0) {
		printf("http_tcpclient_create failed\n");
		return NULL;
	}

	sprintf(lpbuf,
		HTTP_POST,
		file,
		host_addr,
		port,
		(int)strlen(post_str),
		post_str);

	if (http_tcpclient_send(socket_fd, lpbuf, strlen(lpbuf)) < 0) {
		printf("http_tcpclient_send failed..\n");
		return NULL;
	}

	/*it's time to recv from server*/
	if (http_tcpclient_recv(socket_fd,lpbuf) <= 0) {
		printf("http_tcpclient_recv failed\n");
		return NULL;
	}

	http_tcpclient_close(socket_fd);

	return http_parse_result(lpbuf);
}

char *http_get(const char *url)
{
	int socket_fd = -1;
	char lpbuf[BUFFER_SIZE*4] = {'\0'};
	char host_addr[BUFFER_SIZE] = {'\0'};
	char file[BUFFER_SIZE] = {'\0'};
	int port = 0;

	if (!url) {
		printf("failed!\n");
		return NULL;
	}

	if (http_parse_url(url,host_addr,file,&port)) {
		printf("http_parse_url failed!\n");
		return NULL;
	}

	socket_fd = http_tcpclient_create(host_addr,port);
	if (socket_fd < 0) {
		printf("http_tcpclient_create failed\n");
		return NULL;
	}

	sprintf(lpbuf,HTTP_GET,file,host_addr,port);

	if (http_tcpclient_send(socket_fd,lpbuf,strlen(lpbuf)) < 0) {
		printf("http_tcpclient_send failed..\n");
		return NULL;
	}

	if (http_tcpclient_recv(socket_fd,lpbuf) <= 0) {
		printf("http_tcpclient_recv failed\n");
		return NULL;
	}
	http_tcpclient_close(socket_fd);

	return http_parse_result(lpbuf);
}

http.h

#ifndef _MY_HTTP_H
#define _MY_HTTP_H
 
#define MY_HTTP_DEFAULT_PORT 80

char *http_get(const char *url);
char *http_post(const char *url,const char * post_str);
 
#endif