python使用struct解析结构体

falldog

http://blog.chinaunix.net/u2/79621/showart_1210923.html

#!/bin/python
from socket import *
from time import time,ctime
host = ""
port = 12345
bufsize = 1024
addr = (host,port)
socket = socket(AF_INET,SOCK_STREAM)
socket.bind(addr)
socket.listen(5)
try:
while 1:
print "waiting for connection..."
client,addr = socket.accept()
print "..connected from :",addr
while 1:
data = client.recv(bufsize)
if not data:break
print "received:",len(data)
import struct
ip = struct.unpack("HHIII0l",data)
print "ip[0]",ip[0]
print "ip[1]",ip[1]
print "ip[2]",ip[2]
print "ip[3]",ip[3]
break
client.close()
except EOFError:
print 'EOFError  Occur'
except KeyboardInterrupt:
print 'KeyboardInterrupt catched'
finally:
socket.close()

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <errno.h>
extern int errno;
int main(int argc, char **argv)
{
int    sockfd;
struct sockaddr_in  servaddr;
if (argc != 3)
fprintf(stderr, "usage: cmd  <IP> <port>\n");
if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
fprintf(stderr, "socket create error.\n");
exit(1);
}  
bzero(&servaddr, sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_port = htons(atoi(argv[2]));
if ( inet_pton(AF_INET, argv[1], &(servaddr.sin_addr)) < 0) {
fprintf(stderr, "inet_pton error: %s\n", strerror(errno));
close(sockfd);
return -1;
}  
if (connect(sockfd, (struct sockaddr *)&servaddr, sizeof(servaddr)) != 0) {
fprintf(stderr, "connect fail: %s\n", strerror(errno));
exit(1);
}  
int len = sizeof(struct sockaddr_in);
char send[len + 1];
memset(send, 0, len+1);
memcpy(send, &servaddr, len);
//unsigned char sin_len = servaddr.sin_len;
unsigned short sa_family = servaddr.sin_family;
unsigned short sin_port = servaddr.sin_port;
unsigned int  s_addr = servaddr.sin_addr.s_addr;
printf("%u %u %u\n", sa_family, sin_port, s_addr);
int n=0;
n = write(sockfd, send, len);
if (n != len) {
printf("write error\n");
}
printf("write over\n");
exit(0);
}