unix域套接字UDP网络编程

unix域套接字UDP网络编程,服务器如下面：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/un.h>#define SA struct sockaddr
#define PATHNAME "/tmp/unixudp"void err_sys(const char *errmsg);int main(void)
{
int sockfd;
struct sockaddr_un servaddr, cliaddr;
char buf[BUFSIZ];
ssize_t n;
socklen_t len = sizeof(cliaddr); if ((sockfd = socket(AF_LOCAL, SOCK_DGRAM, 0)) == -1)
err_sys("socket"); bzero(&servaddr, sizeof(servaddr));
unlink(PATHNAME);
servaddr.sun_family = AF_LOCAL;
strncpy(servaddr.sun_path, PATHNAME, sizeof(servaddr.sun_path) - 1); if (bind(sockfd, (SA *)&servaddr, sizeof(servaddr)) == -1)
err_sys("bind"); for(;;){
n = recvfrom(sockfd, buf, sizeof(buf), 0, (SA *)&cliaddr, &len);
if (n == -1)
err_sys("recvfrom");
else
printf("%s\n", buf); if (sendto(sockfd, buf, n, 0, (SA *)&cliaddr, sizeof(cliaddr)) != n)
err_sys("sendto"); }
exit(0);
}void err_sys(const char *errmsg)
{
perror(errmsg);
exit(1);
}

client程序：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/un.h>#define SA struct sockaddr
#define PATHNAME "/tmp/unixudp"void err_sys(const char *errmsg);int main(void)
{
int sockfd;
struct sockaddr_un servaddr, localaddr;
char buf[BUFSIZ], s[] = "hello china";
ssize_t n; if ((sockfd = socket(AF_LOCAL, SOCK_DGRAM, 0)) == -1)
err_sys("socket"); bzero(&localaddr, sizeof(localaddr));
localaddr.sun_family = AF_LOCAL;
strncpy(localaddr.sun_path, tmpnam(NULL), sizeof(localaddr.sun_path) - 1); if (bind(sockfd, (SA *)&localaddr, sizeof(localaddr)) == -1)
err_sys("bind"); bzero(&servaddr, sizeof(servaddr));
servaddr.sun_family = AF_LOCAL;
strncpy(servaddr.sun_path, PATHNAME, sizeof(servaddr.sun_path) - 1); for(;;){
if (sendto(sockfd, s, strlen(s), 0, (SA *)&servaddr, sizeof(servaddr)) == -1)
err_sys("sendto");
if ((n = read(sockfd, buf, sizeof(buf))) == -1)
err_sys("read");
else
printf("%s\n", buf);
usleep((rand() % 10) * 10000);
} exit(0);
}void err_sys(const char *errmsg)
{
perror(errmsg);
exit(1);
}