前段时间，帮朋友实现linux C实现HTTP get 及POst请求，最原先打算使用libcurl库实现。但是考虑到和其他接口通信的情况，暂时使用C 来实现.代码可以自动解析URL连接，具体看下面代码：

/*File : http.h
 *Auth : sjin
 *Date : 20141206
 *Mail : 413977243@qq.com
 */
#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
/*File : http.c
 *Auth : sjin
 *Date : 20141206
 *Mail : 413977243@qq.com
 */
#include <stdio.h>
#include <stdlib.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <string.h>
#include "http.h"
#define BUFFER_SIZE 1024
#define HTTP_POST "POST /%s HTTP/1.1rnHOST: %s:%drnAccept: */*rn"
    "Content-Type:application/x-www-form-urlencodedrnContent-Length: %drnrn%s"
#define HTTP_GET "GET /%s HTTP/1.1rnHOST: %s:%drnAccept: */*rnrn"

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] = '';
        if(*(ptr2 + 1)){
            memcpy(file,ptr2 + 1,strlen(ptr2) - 1 );
            file[strlen(ptr2) - 1] = '';
        }
    }else{
        memcpy(host,ptr1,strlen(ptr1));
        host[strlen(ptr1)] = '';
    }
    //get host and ip
    ptr1 = strchr(host,':');
    if(ptr1){
        *ptr1++ = '';
        *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 faindn");
        return NULL;
    }
    if(atoi(ptmp + 9)!=200){
        printf("result:n%sn",lpbuf);
        return NULL;
    }
    ptmp = (char*)strstr(lpbuf,"rnrn");
    if(!ptmp){
        printf("ptmp is NULLn");
        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){
    char post[BUFFER_SIZE] = {''};
    int socket_fd = -1;
    char lpbuf[BUFFER_SIZE*4] = {''};
    char *ptmp;
    char host_addr[BUFFER_SIZE] = {''};
    char file[BUFFER_SIZE] = {''};
    int port = 0;
    int len=0;
	char *response = NULL;
    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;
    }
    //printf("host_addr : %stfile:%st,%dn",host_addr,file,port);
    socket_fd = http_tcpclient_create(host_addr,port);
    if(socket_fd < 0){
        printf("http_tcpclient_create failedn");
        return NULL;
    }
     
    sprintf(lpbuf,HTTP_POST,file,host_addr,port,strlen(post_str),post_str);
    if(http_tcpclient_send(socket_fd,lpbuf,strlen(lpbuf)) < 0){
        printf("http_tcpclient_send failed..n");
        return NULL;
    }
	//printf("发送请求:n%sn",lpbuf);
    /*it's time to recv from server*/
    if(http_tcpclient_recv(socket_fd,lpbuf) <= 0){
        printf("http_tcpclient_recv failedn");
        return NULL;
    }
    http_tcpclient_close(socket_fd);
    return http_parse_result(lpbuf);
}
char * http_get(const char *url)
{
    char post[BUFFER_SIZE] = {''};
    int socket_fd = -1;
    char lpbuf[BUFFER_SIZE*4] = {''};
    char *ptmp;
    char host_addr[BUFFER_SIZE] = {''};
    char file[BUFFER_SIZE] = {''};
    int port = 0;
    int len=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;
    }
    //printf("host_addr : %stfile:%st,%dn",host_addr,file,port);
    socket_fd =  http_tcpclient_create(host_addr,port);
    if(socket_fd < 0){
        printf("http_tcpclient_create failedn");
        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;
    }
//	printf("发送请求:n%sn",lpbuf);
    if(http_tcpclient_recv(socket_fd,lpbuf) <= 0){
        printf("http_tcpclient_recv failedn");
        return NULL;
    }
    http_tcpclient_close(socket_fd);
    return http_parse_result(lpbuf);
}

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