getsockname奇怪问题？

2009-07-0423:23:09

---

extern int errno;
#include <errno.h>
#include <stdio.h>
#include <unistd.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <strings.h>
#define SA struct sockaddr
#define MAXLINE 4096
int main(int argc,char **argv)
{
    int n,sockfd;
    socklen_t sslen;
    char recvline[MAXLINE];
    struct sockaddr_in servsock,ss;
    if( argc != 2)
 printf("paramer is error");
    if( (sockfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
 printf("socket error:%s/n",strerror(errno));
    bzero(&servsock,sizeof(servsock));
    servsock.sin_port = htons(50000);
    servsock.sin_family = AF_INET;

    if( (inet_pton(AF_INET,argv[1],&servsock.sin_addr.s_addr) <= 0))
 printf("inet_pton error:%s/n",strerror(errno));
/*    bzero(&ss,sizeof(ss));
    ss.sin_port = htons(30000);
    ss.sin_family = AF_INET;
    ss.sin_addr.s_addr = htonl(INADDR_ANY);*/
    sslen = sizeof(struct sockaddr_in);
    //inet_pton(AF_INET,"192.168.1.20",&ss.sin_addr.s_addr);
    //bind(sockfd,(SA *)&ss,sslen);
    if( connect(sockfd,(SA *)&servsock,sizeof(servsock)) < 0)
 printf("connect error:%s/n",strerror(errno));
if( getsockname(sockfd, (SA *)&ss,&sslen) < 0)
 printf("getsockname error:%s/n",strerror(errno));
    else
 printf("Bind IP = [%s]/tport = [%s]/n",
  inet_ntop(AF_INET,&ss.sin_addr.s_addr,recvline,MAXLINE),
  ntohs(ss.sin_port));
 /*   printf("%s/n",recvline);
getsockname(sockfd, (SA *)&ss,&sslen);
    printf("sslen=%d/t[%s]/t[%d]/n",sslen,inet_ntop(AF_INET,&ss.sin_addr.s_addr,recvline,sizeof(recvline)), ntohs(ss.sin_port));*/
    bzero(recvline,sizeof(recvline));
    while( (n = read(sockfd,recvline,MAXLINE)) > 0)
    {
 recvline[n] = 0;
 if( fputs(recvline,stdout) == EOF)
     printf("fputs error/n");
    }
    if(n < 0)
 printf("read error/n");
    exit(0);
}

 

很奇怪的问题不知道为什么getsockname放到if里就不能显示输出为空

而放在外面就好用

现在注释的那段程序。