/* server.c * Copyright Mark Watson 1999. Open Source Software License. */#include <stdio.h>#include <sys/socket.h>#include <netinet/in.h>#include <arpa/inet.h>#include <netdb.h>      int port = 8000;void main() {  struct sockaddr_in sin;  struct sockaddr_in pin;  int sock_descriptor;  int temp_sock_descriptor;  int address_size;  char buf[16384];  int i, len;  sock_descriptor = socket(AF_INET, SOCK_STREAM, 0);  if (sock_descriptor == -1) {    perror("call to socket");    exit(1);  }  bzero(&sin, sizeof(sin));  sin.sin_family = AF_INET;  sin.sin_addr.s_addr = INADDR_ANY;  sin.sin_port = htons(port);  if (bind(sock_descriptor, (struct sockaddr *)&sin, sizeof(sin)) == -1) {    perror("call to bind");    exit(1);  }  if (listen(sock_descriptor, 20) == -1) {    perror("call to listen");    exit(1);  }  printf("Accepting connections ...\n");   while(1) {    temp_sock_descriptor =      accept(sock_descriptor, (struct sockaddr *)&pin,	     &address_size);    if (temp_sock_descriptor == -1) {      perror("call to accept");      exit(1);    }    if (recv(temp_sock_descriptor, buf, 16384, 0) == -1) {      perror("call to recv");      exit(1);    }    printf("received from client:%s\n", buf);    // for this server example, we just convert the    // characters to upper case:    len = strlen(buf);    for (i=0; i<len; i++) buf[i] = toupper(buf[i]);        if (send(temp_sock_descriptor, buf, len, 0) == -1) {      perror("call to send");      exit(1);    }    close(temp_sock_descriptor);  }}