ubuntu 上 新建大文件 超过2G

/**
 author lx
 date 3.24 2011
 contact lxlenovostar@gmail.com
 biref cp a big file to anthor file.
*/

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>

#define BUFFSIZE 8192

int main( void )
{
int id_write, id_read;

        id_write = open( "temp.pcap", O_WRONLY | O_APPEND | O_CREAT );
        id_read = open( "lx03.pcap", O_RDONLY );

int n;
char buf[BUFFSIZE];
while ( ( n = read( id_read, buf, BUFFSIZE ) ) > 0 )
        {
if ( write( id_write, buf, n ) != n )
                        fprintf( stderr, "error is %s\n", strerror(errno) );
        }       

if ( n < 0 )
                printf( "read error\n" );

        close( id_write );
        close( id_read );       

        exit( 0 );
}　　　　　　　　　　　　　

编译的时候：g++ -o opencp  -D_FILE_OFFSET_BITS=64 -g opencp.cpp