1
int listen(int sockfd, int backlog);

1
int accept(int sockfd, struct sockaddr *_Nullable restrict addr,
2
           socklen_t *_Nullable restrict addrlen);
3

4
int accept4(int sockfd, struct sockaddr *_Nullable restrict addr,
5
            socklen_t *_Nullable restrict addrlen, int flags);

1
int connect(int sockfd, const struct sockaddr *addr, socklen_t addrlen);

1
#include "netinet/in.h"
2
#include "netinet/ip.h"
3
#include "proto.h"
4
#include "stdio.h"
5
#include "stdlib.h"
6
#include "string.h"
7
#include "sys/socket.h"
8
#include <arpa/inet.h>
9
#define BUFFSIZE 1024
10
#define IPSIZE 24
11
#define SERVER_PORT "2233"
12

13
int main() {
14
  int sd;
15
  sd = socket(AF_INET, SOCK_STREAM, 0);
16

17
  int val = 1;
18
  if (setsockopt(sd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val))) {
19
    perror("setsockop()");
20
    exit(1);
21
  }
22

23
  if (sd < 0) {
24
    perror("socket");
25
    exit(1);
26
  }
27
  struct sockaddr_in s_addr;
28
  struct sockaddr_in c_addr;
29
  memset(&s_addr, 0, sizeof(s_addr));
30
  s_addr.sin_family = AF_INET;
31
  s_addr.sin_port = htons(atoi(SERVER_PORT));
32
  inet_pton(sd, "0.0.0.0", &s_addr.sin_addr);
33

34
  socklen_t socklen = sizeof(s_addr);
35
  socklen_t c_socklen = sizeof(c_addr);
36

37
  if (bind(sd, (void *)&s_addr, socklen) < 0) {
38
    perror("bind()");
39
    exit(1);
40
  }
41
  if (listen(sd, 100) < 0) {
42
    perror("listen");
43
    exit(1);
44
  }
45
  int new_sd;
46

47
  new_sd = accept(sd, &c_addr, &c_socklen);
48
  if (new_sd < 0) {
49
    perror("accept()");
50
    exit(1);
51
  }
52
  FILE *sock_fl;
53
  sock_fl = fdopen(new_sd, "w");
54
  if (sock_fl == NULL) {
55
    perror("fdopen()");
56
    exit(1);
57
  }
58
  char addr[22];
59
  inet_ntop(AF_INET, &c_addr.sin_addr, addr, c_socklen);
60
  int port = ntohs(c_addr.sin_port);
61
  fprintf(sock_fl, "Hello %s:%d \n", addr, port);
62
  fclose(sock_fl);
63
  return 0;
64
}

1
#include "arpa/inet.h"
2
#include "netinet/ip.h"
3
#include "proto.h"
4
#include "stdio.h"
5
#include "stdlib.h"
6
#include "string.h"
7
#include "sys/socket.h"
8

9
#define BUFF_SIZE 2048
10
#define SERVER_PORT "2233"
11

12
int main(int argc, char *argv[]) {
13
  int sd;
14
  sd = socket(AF_INET, SOCK_STREAM, 0);
15
  if (sd < 0) {
16
    perror("socket()");
17
    exit(1);
18
  }
19
  struct sockaddr_in s_addr;
20
  s_addr.sin_family = AF_INET;
21
  inet_pton(AF_INET, "0.0.0.0", &s_addr.sin_addr);
22
  s_addr.sin_port = htons(atoi(SERVER_PORT));
23

24
  socklen_t socklen = sizeof(s_addr);
25

26
  if (connect(sd, &s_addr, socklen) < 0) {
27
    perror("connect()");
28
    exit(1);
29
  }
30

31
  FILE *sock_fl;
32
  sock_fl = fdopen(sd, "r");
33
  if (sock_fl == NULL) {
34
    perror("sock_fl()");
35
    exit(1);
36
  }
37
  char buf[BUFF_SIZE];
38
  int cnt;
39

40
  while ((cnt = fread(buf, 1, BUFF_SIZE, sock_fl)) > 0) {
41
    // 使用 fwrite 将读取到的 cnt 字节直接写入标准输出
42
    fwrite(buf, 1, cnt, stdout);
43
  }
44

45
  fclose(sock_fl);
46
  return 0;
47
}