Using C language to write socket communication program based on TCP protocol sharing _c language

TCP Client Example

#include <errno.h> #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> #in Clude <stdlib.h> #include <string.h> #include <netinet/in.h> #include <stdio.h> #include <u nistd.h> #include <sys/types.h> #include <sys/socket.h> typedef struct _NSS_HEADER {unsigned shor    T protocolversion;        /* Protocol version Information * * unsigned short msgtype;     /* Message Type * * unsigned short Transactionno;      /* Transmission Number * * unsigned short packetlength;  
 
/* packet length, including HEADER */}nss_header; 
  int Str_echo (int sockfd, unsigned short no) {ssize_t readlen; 
  ssize_t Writelen; 
 
  Char Buf[8]; 
  Nss_header *HDR = (nss_header*) buf; 
  memset (HDR, 0, sizeof (nss_header)); 
 
  Hdr->transactionno = no; 
  Write data int nwritelen = 0; 
while (true) {Writelen = write (SOCKFD, &buf[nwritelen], sizeof (Nss_header)-nwritelen); 
    
    printf ("Write%d/n", Writelen); if (WRITelen < 0 && errno = = eintr) {continue; 
      else if (Writelen < 0) {perror ("write:"); 
    return-1; 
    } Nwritelen + = Writelen; 
    Finished writing, return directly if (Nwritelen >= sizeof (Nss_header)) {break; } printf ("Send data successed.") 
 
  Trans No:%d/n ", no); 
  Read Data int nreadlen = 8; 
while (true) {Readlen = Read (SOCKFD, buf, Nreadlen); 
    printf ("read:%d/n", Readlen); 
    if (Readlen < 0 && errno = = eintr) {continue; 
      else if (Readlen <= 0) {perror ("read:"); 
    return-1; 
      else {Nreadlen-= Readlen; 
      if (Nreadlen <= 0) {break; 
 
  } printf ("Read response successed./n"); 
return 0; 
  int main (int argc, char **argv) {printf ("Client IP:%s/n", argv[1]); 
  printf ("Client port:%s/n", argv[2]); printf ("Server IP:%s/n", argv[3]); 
 
  printf ("Server port:%s/n", argv[4]); 
  printf ("/N Service starting.../n/n"); 
    while (true) {int socketfd; 
    struct sockaddr_in svraddr; 
 
    struct sockaddr_in localaddr; 
    SOCKETFD = socket (af_inet, sock_stream, 0); 
      if (-1 = socketfd) {perror ("socket:"); 
    Continue 
    //SET ADDRESS reusable int option = 1; 
    SetSockOpt (SOCKETFD, Sol_socket, so_reuseaddr, &option, sizeof (option)); 
    Client IP memset (&localaddr, 0, sizeof (LOCALADDR)); 
    localaddr.sin_family = af_inet; 
    LOCALADDR.SIN_ADDR.S_ADDR = inet_addr (argv[1]); 
 
    Localaddr.sin_port = htons (atoi (argv[2)); 
    int bindresult = bind (Socketfd, (struct sockaddr *) &localaddr, sizeof (LOCALADDR)); 
      if (-1 = bindresult) {perror ("bind:"); 
      Sleep (10); 
      Close (SOCKETFD); 
    Continue 
    }//server IP memset (&svraddr, 0, sizeof (SVRADDR)); 
    svraddr.sin_family = af_inet; Svraddr. sin_addr.s_addr = inet_addr (argv[3]); 
 
    Svraddr.sin_port = htons (atoi (argv[4)); 
    continuously connected int connresult = connect (socketfd, (struct sockaddr *) &svraddr, sizeof (SVRADDR)); 
      if (-1 = connresult) {perror ("Connect:"); 
      Sleep (10); 
      Close (SOCKETFD); 
    Continue 
 
    printf ("Connect%s:%s successed./n", argv[3], argv[4]); 
    static unsigned short no = 0; 
    Connection successful, send data per minute for (;;) 
      {if (-1 = = Str_echo (socketfd, no++)) {break; 
    Sleep (60); 
  Close (SOCKETFD); 
 } 
}

TCP Server Source code example

#include <errno.h> #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> #in Clude <stdlib.h> #include <string.h> #include <netinet/in.h> #include <stdio.h> #include <u nistd.h> #include <sys/types.h> #include <sys/socket.h> struct _nss_header {unsigned short Pr    Otocolversion;        /* Protocol version Information * * unsigned short msgtype;     /* Message Type * * unsigned short Transactionno;      /* Transmission Number * * unsigned short packetlength;  
 
/* packet length, including HEADER */}nss_header; 
  void Str_echo (int sockfd) {ssize_t readlen; 
  ssize_t Writelen; 
 
  Char Buf[8]; 
    while (true) {Readlen = Read (SOCKFD, buf, 8); 
    if (Readlen < 0 && errno = = eintr) {continue; 
      else if (Readlen <= 0) {perror ("read:"); 
    return; printf ("recv data successed.") 
 
    Data len:%d/n ", Readlen); 
    int nwritelen = 0; while (tRue) {Writelen = = write (SOCKFD, &buf[nwritelen), Readlen-nwritelen); 
      if (Writelen < 0 && errno = = eintr) {continue; 
        else if (Writelen < 0) {perror ("write:"); 
      Return 
 
      } Nwritelen + = Writelen; 
      has been written, directly returns if (Nwritelen >= Readlen) {break; } printf ("Send data successed.") 
  Data len:%d/n ", Readlen); 
  int main (int argc, char **argv) {printf ("Server IP:%s/n", argv[1)); 
 
  printf ("Server port:%s/n", argv[2]); 
 
  printf ("/nservice starting .../n/n"); 
  int LISTENFD, CONNFD; 
  pid_t Childpid; 
  Socklen_t Clilen; 
 
  struct sockaddr_in cliaddr, servaddr; 
  LISTENFD = socket (af_inet, sock_stream, 0); 
    if (-1 = listenfd) {perror ("socket:"); 
  Exit (-1); 
  //SET ADDRESS reusable int option = 1; SetSockOpt (LISTENFD, Sol_socket, so_reuseaddr, &option, sizeof (option)); 
  memset (&servaddr, 0, sizeof (SERVADDR)); 
  servaddr.sin_family = af_inet; 
  SERVADDR.SIN_ADDR.S_ADDR = inet_addr (argv[1]); 
 
  Servaddr.sin_port = htons (atoi (argv[2)); 
  int bindresult = bind (LISTENFD, (struct sockaddr *) &servaddr, sizeof (SERVADDR)); 
    if (-1 = bindresult) {perror ("bind:"); 
  Exit (-1); 
  int listenresult = Listen (LISTENFD, 5); 
    if (-1 = listenresult) {perror ("listen:"); 
  Exit (-1);  
  for (;;) 
    {Clilen = sizeof (CLIADDR); 
    CONNFD = Accept (LISTENFD, (struct sockaddr *) &cliaddr, &clilen); 
      if (-1 = connfd) {perror ("Accept:"); 
    Continue 
 
    printf ("Accept%s SUCCESSED.FD:%d/n", Inet_ntoa (CLIADDR.SIN_ADDR), CONNFD);  if ((Childpid = fork ()) = = 0) {/* child process */close (LISTENFD);  /* Close Listening socket * * STR_ECHO (CONNFD); /* Process the request/printf ("Disconnect from%d./n", CONNFD); 
    Exit (0);     } close (CONNFD);  /* Parent Closes connected socket */}