网络编程 单纯http客户端，服务器端

http客户端：

#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <errno.h>
#include <netdb.h>
#include <string.h>
#include <unistd.h>
int main(int argc, char* argv[]){
  int err;
  int sock;
  char buf[32];
  char* deststr;
  addrinfo hints, *res0, *res;
  if(argc != 2){return 1;}
  deststr = argv[1];
  memset(&hints, 0, sizeof(hints));
  hints.ai_socktype = SOCK_STREAM;
  hints.ai_family = PF_UNSPEC;
  if((err = getaddrinfo(deststr, "http", &hints, &res0)) != 0){
    printf("error %d:%s\n", err, gai_strerror(err));
    return 1;
  }
  for(res = res0; res != NULL; res = res->ai_next){
    printf("%d\n", res->ai_family);
    sock = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
    if(sock < 0){continue;}
    if(connect(sock, res->ai_addr, res->ai_addrlen) != 0){
      close(sock);
      continue;
    }
    break;
  }
  freeaddrinfo(res0);
  if(res == NULL){
    printf("failed\n");
    return 1;
  }
  snprintf(buf, sizeof(buf), "GET / HTTP/1.0\r\n\r\n");
  int n = write(sock, buf, (int)strlen(buf));
  while(n > 0){
    n = read(sock, buf, sizeof(buf));
    write(fileno(stdout), buf, n);
  }
  close(sock);
  return 0;
}

github源代码

发送端的执行方式：

./a.out www.baidu.com

http服务器端

#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <errno.h>
#include <netdb.h>
#include <string.h>
#include <unistd.h>
int main(){
  int sock0;
  sockaddr_in client;
  socklen_t len;
  int sock;
  int yes = 1;
  addrinfo *res, hints;
  int err;
  char buf[2048];
  int n;
  char inbuf[2048];
  hints.ai_family = AF_INET;
  hints.ai_flags = AI_PASSIVE;
  hints.ai_socktype = SOCK_STREAM;
  err = getaddrinfo(NULL, "12345", &hints, &res);
  if(err != 0){
    printf("getaddrinfo %s\n", gai_strerror(err));
    return 1;
  }
  sock0 = socket(res->ai_family, res->ai_socktype, 0);
  setsockopt(sock0, SOL_SOCKET, SO_REUSEADDR, (const char*)&yes, sizeof(yes));
  bind(sock0, res->ai_addr, res->ai_addrlen);
  listen(sock0, 5);
  snprintf(buf, sizeof(buf),
       "HTTP/1.0 200 OK\r\n"
       "Content-Length: 20\r\n"
       "Content-Type:text/html\r\n"
       "\r\n"
       "HELLO\r\n");
  while(1){
    len = sizeof(client);
    sock = accept(sock0, (sockaddr*)&client, &len);
    n = read(sock, inbuf, sizeof(inbuf));
    write(fileno(stdout), inbuf, n);
    write(sock, buf, (int)strlen(buf));
    close(sock);
  }
  close(sock0);
  return 0;
}

github源代码

测试方式：

在浏览器里输入：http://127.0.0.1:12345
或者输入：http://localhost:12345