server.c

linux环境下网络编程的example代码

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <sys/wait.h>

#define MYPORT 3490 /* the port users will be connecting to */
#define BACKLOG 10 /* how many pending connections queue will hold */

main()
{
int sockfd, new_fd; /* listen on sock_fd, new connection on new_fd */
struct sockaddr_in my_addr; /* my address information */
struct sockaddr_in their_addr; /* connector's address information */
int sin_size;

if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
perror ( " socket " ) ;
exit(1) ;
}

my_addr.sin_family = AF_INET;
my_addr.sin_port = htons(MYPORT);
my_addr. sin_addr.s_addr = INADDR_ANY; /* auto-fill with my IP */

if (bind(sockfd, (struct sockaddr *)&my_addr, sizeof(struct sockaddr)) == -1) {
perror ( " bind" ) ;
exit(1) ;
}

if (listen(sockfd, BACKLOG) == -1) {
perror ( " listen " ) ;
exit(1) ;
}

while(1) { /* main accept() loop */
sin_size = sizeof(struct sockaddr_in);
if ((new_fd = accept(sockfd, (struct sockaddr *)&their_addr, 
&sin_size)) == -1) {
perror ( " accept " ) ;
continue ;
}
printf("server: got connection from %s\n", inet_ntoa(their_addr.sin_addr) ) ;
if (!fork()) { /* this is the child process */
if (send(new_fd, "Hello, world!\n", 14, 0) == -1)
perror( " send " ) ;
close( new_fd ) ;
exit ( 0 ) ;
}
close(new_fd); /* parent doesn't need this */
while(waitpid(-1,NULL,WNOHANG) > 0); /* clean up child processes */
}
}