UDP特点:
套接口具有两个属性:
本地地址 getsockname()
远程地址 getpeername()
调用sento时进行绑定。
echosrv.c
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#define ERR_EXIT(m) \
do \
{ \
perror(m); \
exit(EXIT_FAILURE); \
} while(0)
void echo_srv(int sock)
{
char recvbuf[1024] = {0};
struct sockaddr_in peeraddr;
socklen_t peerlen;
int n;
while (1)
{
peerlen = sizeof(peeraddr);
memset(recvbuf, 0, sizeof(recvbuf));
n = recvfrom(sock, recvbuf, sizeof(recvbuf), 0, (struct sockaddr*)&peeraddr, &peerlen);
if (n == -1)
{
if (errno == EINTR)
continue;
ERR_EXIT("recvfrom");
}
else if (n > 0)
{
fputs(recvbuf, stdout);
sendto(sock, recvbuf, n, 0, (struct sockaddr*)&peeraddr, peerlen);
}
}
close(sock);
}
int main(void)
{
int sock;
if ((sock = socket(PF_INET, SOCK_DGRAM, 0)) < 0)
ERR_EXIT("socket");
struct sockaddr_in servaddr;
memset(&servaddr, 0, sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_port = htons(5188);
servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
if (bind(sock, (struct sockaddr*)&servaddr, sizeof(servaddr)) < 0)
ERR_EXIT("bind");
echo_srv(sock);
return 0;
}
echocli.c
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#define ERR_EXIT(m) \
do \
{ \
perror(m); \
exit(EXIT_FAILURE); \
} while(0)
void echo_cli(int sock)
{
struct sockaddr_in servaddr;
memset(&servaddr, 0, sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_port = htons(5188);
servaddr.sin_addr.s_addr = inet_addr("127.0.0.1");
connect(sock, (struct sockaddr*)&servaddr, sizeof(servaddr));
int ret;
char sendbuf[1024] = {0};
char recvbuf[1024] = {0};
while (fgets(sendbuf, sizeof(sendbuf), stdin) != NULL)
{
/*sendto(sock, sendbuf, strlen(sendbuf), 0, (struct sockaddr*)&servaddr, sizeof(servaddr));*/
/*sendto(sock, sendbuf, strlen(sendbuf), 0, NULL, 0);*/
send(sock, sendbuf, strlen(sendbuf), 0);
ret = recvfrom(sock, recvbuf, sizeof(recvbuf), 0, NULL, NULL);
if (ret == -1)
{
if (errno == EINTR)
continue;
ERR_EXIT("recvfrom");
}
fputs(recvbuf, stdout);
memset(sendbuf, 0, sizeof(sendbuf));
memset(recvbuf, 0, sizeof(recvbuf));
}
close(sock);
}
int main(void)
{
int sock;
if ((sock = socket(PF_INET, SOCK_DGRAM, 0)) < 0)
ERR_EXIT("socket");
echo_cli(sock);
return 0;
}
trun.c
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#define ERR_EXIT(m) \
do \
{ \
perror(m); \
exit(EXIT_FAILURE); \
} while(0)
int main(void)
{
int sock;
if ((sock = socket(PF_INET, SOCK_DGRAM, 0)) < 0)
ERR_EXIT("socket");
struct sockaddr_in servaddr;
memset(&servaddr, 0, sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_port = htons(5188);
servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
if (bind(sock, (struct sockaddr*)&servaddr, sizeof(servaddr)) < 0)
ERR_EXIT("bind");
sendto(sock, "ABCD", 4, 0, (struct sockaddr*)&servaddr, sizeof(servaddr));
char recvbuf[1];
int n;
int i;
for (i=0; i<4; i++)
{
n = recvfrom(sock, recvbuf, sizeof(recvbuf), 0, NULL, NULL);
if (n == -1)
{
if (errno == EINTR)
continue;
ERR_EXIT("recvfrom");
}
else if(n > 0)
printf("n=%d %c\n", n, recvbuf[0]);
}
return 0;
}
makefile:
.PHONY:clean all
CC=gcc
CFLAGS=-Wall -g
BIN=echosrv echocli trunc
all:$(BIN)
%.o:%.c
$(CC) $(CFLAGS) -c $< -o $@
clean:
rm -f *.o $(BIN)
ubuntu下安装rabbitmq-c-master,布布扣,bubuko.com
原文:http://blog.csdn.net/leekwen/article/details/25868859