#include <sys/socket.h>

#include <netinet/in.h>

#include <arpa/inet.h>

#include <unistd.h>

#include <stdlib.h>

#include <assert.h>

#include <stdio.h>

#include <string.h>

#include <errno.h>

int main (int argc, char* argv[])

{

if( argc<=2 ){

printf("usage:%s ip_address port_number \n", basename(argv[0]));

return 1;

}

const char* ip = argv[1];

int port = atoi( argv[2] );

//创建一个IPv4 socket地址

struct sockaddr_in address;

bzero( &address, sizeof( address ) );

address.sin_family = AF_INET;

inet_pton( AF_INET, ip, &address.sin_addr );

address.sin_port = htons( port );

int sock = socket( PF_INET, SOCK_STREAM, 0);

assert( sock >= 0 );

int ret = bind(sock,(struct sockaddr*)&address, sizeof(address));

assert( ret != 1 );

ret = listen(sock,5);

assert( ret != 1 );

struct sockaddr_in client;

socklen_t client_addrlength = sizeof( client );

int connfd = accept( sock, (struct sockaddr*)&client, &client_addrlength);

if( connfd < 0 )

{

printf("errno is:%d\n",errno);

}

else

{

close(STDOUT_FILENO);

dup(connfd);

printf("abcd\n");

close(connfd);

}

close(sock);

return 0;

}