client.c

中科院徐志伟老师一书《操作系统 原理·技术与编程》的源代码和习题接

#include <stdio.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>

char * host_name = "127.0.0.1";  /* local host */
int port = 8000;

void main(int argc, char *argv[]) {
  char buf[8192];
  char message[256];
  int sockfd, n;
  struct sockaddr_in pin;
  struct hostent *shost_name;

  if ((shost_name = gethostbyname(host_name)) == 0) {
    perror("Error resolving local host\n");
    exit(1);
  }
    
  bzero(&pin, sizeof(pin));
  pin.sin_family = AF_INET;
  pin.sin_addr.s_addr = htonl(INADDR_ANY);
  pin.sin_addr.s_addr = ((struct in_addr *)(shost_name->h_addr))->s_addr;
  pin.sin_port = htons(port);

  if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
    perror("Error opening socket\n");
    exit(1);
  }
  if (connect(sockfd, (void *)&pin, sizeof(pin)) == -1) {
    perror("Error connecting to socket\n");
    exit(1);
  }
  sprintf(message,"What is the time and date\n");
  printf("Sending message %s to server...\n", message);

  if (write(sockfd, message, strlen(message)) == -1) {
    perror("Error in write\n");
    exit(1);
  }
  printf("..sent message.. wait for response...\n");

  while( (n = read(sockfd, buf, 8192)) >0) {
	buf[n] = 0;
	if(fputs(buf,stdout) == EOF)
	{
    		perror("Error fputs\n");
	    	exit(1);
	}
  }
  if(n<0){
    	printf("\nResponse from server:\n\n%s\n", buf);
	exit(1);
  }
  close(sockfd);
}