Socket communication implemented under Centos 64

Source:

    /* File NAME:SERVER.C */#include <stdio.h> #include <stdlib.h> #include <string.h> #include <errno.h> #include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h      >//ineternet Address family #include <arpa/inet.h> #define DEFAULT_PORT 8000 #define MAXLINE 4096          int main (int argc, char** argv) {int socket_fd, CONNECT_FD;          struct sockaddr_in servaddr;          Char buff[4096];          int n; Initialize socket if (SOCKET_FD = socket (af_inet, sock_stream, 0)) = =-1) {printf ("Create Socket Error:%s (E          Rrno:%d) \ n ", Strerror (errno), errno);          Exit (0);          }//Initialize memset (&servaddr, 0, sizeof (SERVADDR));          servaddr.sin_family = af_inet;          SERVADDR.SIN_ADDR.S_ADDR = htonl (Inaddr_any),//IP address is set to Inaddr_any, the system automatically gets the IP address of the machine. Servaddr.sin_port = htons (default_port);//Set the port to Default_porT//Bind the local address to the created socket on if (bind (socket_fd, struct sockaddr*) &servaddr, sizeof (servaddr)) = = 1)          {printf ("Bind socket Error:%s (errno:%d) \ n", Strerror (errno), errno);          Exit (0); }//Start listening If there is a client connection if (listen (socket_fd) = =-1) {printf ("Listen socket Error:%s (errno:%d) \ n          ", Strerror (errno), errno);          Exit (0);          } printf ("======waiting for client ' s request======\n");  while (1) {struct sockaddr_in cilent_addr;    Client socket address structure socklen_t length = sizeof (CILENT_ADDR);            Blocking until there is a client connection, or more wasted CPU resources. if (connect_fd = Accept (socket_fd, (struct sockaddr*) &cilent_addr, &length)) = =-1) {//             The client's socket address structure is filled into the CILENT_ADDR structure of printf ("Accept socket Error:%s (errno:%d)", Strerror (errno), errno);             Continue  }//Accept data sent by the client n = recv (connect_fd, Buff, MAXLINE, 0);        if (n < 0) {printf ("Server Receive Data faild!\n"); ToThe client sends the response data if (!fork ()) {/* Child process */if (send (CONNECT_FD, "Hello,you is connected!\n", 26,0) = =-1)              Perror ("Send Error");              Close (CONNECT_FD);              Exit (0);          } Buff[n] = ' + ';  printf ("Recv msg from client:%s\n", buff); printf ("has a cilent connect IP%s!\n", Inet_ntoa (CILENT_ADDR.SIN_ADDR));          Print out client address information close (CONNECT_FD);      } close (SOCKET_FD);   }

    /* File name:client.c */#include <stdio.h> #include <stdlib.h> #include &LT;STRING.H&G      T #include <errno.h> #include <sys/types.h> #include <sys/socket.h> #include &LT;NETINET/IN.H&G            T          #define MAXLINE 4096 int main (int argc, char** argv) {int sockfd, N,rec_len;          Char recvline[4096], sendline[4096];          Char Buf[maxline];                      struct sockaddr_in servaddr;          if (argc! = 2) {printf ("Usage:./client <ipaddress>\n");          Exit (0); } if ((SOCKFD = socket (af_inet, sock_stream, 0)) < 0) {printf ("Create Socket Error:%s (er          Rno:%d) \ n ", Strerror (errno), errno);          Exit (0);          } memset (&servaddr, 0, sizeof (SERVADDR));          servaddr.sin_family = af_inet;          Servaddr.sin_port = htons (8000); if (Inet_pton (Af_inet, argv[1], & servaddr.sin_addr) <= 0) {printf ("Inet_pton error for%s\n", argv[1]);          Exit (0); } if (Connect (SOCKFD, (struct sockaddr*) &servaddr, sizeof (SERVADDR)) < 0) {printf ("Co          Nnect Error:%s (errno:%d) \ n ", Strerror (errno), errno);          Exit (0);          } printf ("Send msg to server: \ n");          Fgets (Sendline, 4096, stdin); if (Send (SOCKFD, Sendline, strlen (Sendline), 0) < 0) {printf ("Send msg Error:%s (errno:%d) \ n", stre          Rror (errno), errno);          Exit (0);             } if ((Rec_len = recv (SOCKFD, buf, maxline,0)) = =-1) {perror ("recv error");          Exit (1);          } Buf[rec_len] = ' + ';          printf ("Received:%s", buf);          Close (SOCKFD);      Exit (1);   }

Encountered a problem:

Inet_ntoa () End error with 64-bit CentOS:

Segmentation fault (core dumped)

32 bit Normal printing, 64 bit is a segment error, wrong on HADDRP This parameter, the error content is that the return value of Inet_ntoa is an int, so%s cannot output.

Workaround:

1. If you need to #include <arpa/inet.h> with Inet_ntoa () , it is normal.

2. Using Inet_ntop ()

Finally, the server-side porting via ARM-LINUX-GCC cross-compiler to the Development Board works fine.

Socket communication implemented under Centos 64