#define _FILE_OFFSET_BITS 64

------解决方案--------------------
AIX平台可以这样：
1、编译时增加宏定义_LARGE_FILES，如：xlC -D_LARGE_FILES t.cpp
2、使用fopen64代替fopen
3、程序编译为64位，如：xlC -q64 t.cpp

对于其他unix平台，lz可以尝试一下，编译为64位程序应该是通用的方式

------解决方案--------------------
你用 open, write, read这些函数，你会发现里头的参数是read, write是size_t 或off_t (lseek);
所以你在编译的时候加入  -DLARGE_FILE  - D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64
即可！
应用层使用参数尽量用size_t, off_t。

------解决方案--------------------
在 windows 下可以用 CreateFile来打开文件 用 SetFilePointer来定位，用ReadFile来读取。这样多大的文件都可以读。

------解决方案--------------------
windows下用文件内存映射，参考《windows核心编程》17章----内存映射文件
linux下用mmap，参考《UNIX环境高级编程》14章----14.9 存储映射I/O

------解决方案--------------------
#define _LARGEFILE_SOURCE
#define _LARGEFILE64_SOURCE
#define _FILE_OFFSET_BITS 64

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>

int main(int argc, char *argv[])
{
       int fd;

       fd = open("a.txt", O_RDWR|O_CREAT|O_LARGEFILE, 0644);
       if (fd==-1){
               error("open");
               exit(-1);
       }

       close(fd);

       return 0;
}

如上代码定义上面那3个宏，然后再open的参数里加一个O_LARGEFILE，即可！

------解决方案--------------------
 一个简单的问题竟然这么多人围观？
  #man lseek64
  不就啥都清楚了？

－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－
NAME
      lseek64 - reposition 64-bit read/write file offset

SYNOPSIS
      #define _LARGEFILE64_SOURCE
      #include <sys/types.h>
      #include <unistd.h>

      off64_t lseek64(int fd, off64_t offset, int whence);

DESCRIPTION
      The  lseek(2) family of functions reposition the offset of the open file associated with the file descrip-
      tor fd to offset bytes relative to the start, current position, or end of the file, when  whence  has  the
      value SEEK_SET, SEEK_CUR, or SEEK_END, respectively.

      For more details, return value, and errors, see lseek(2).

      Four interfaces are available: lseek(), lseek64(), llseek(), and the raw system call _llseek().

  lseek
      Prototype:

           off_t lseek(int fd, off_t offset, int whence);

      The  library  routine  lseek() uses the type off_t.  This is a 32-bit signed type on 32-bit architectures,
      unless one compiles with

           #define _FILE_OFFSET_BITS 64

      in which case it is a 64-bit signed type.

  lseek64
      Prototype:

           off64_t lseek64(int fd, off64_t offset, int whence);

      The library routine lseek64() uses a 64-bit type even when off_t is a 32-bit type. Its prototype (and  the
      type off64_t) is available only when one compiles with

           #define _LARGEFILE64_SOURCE

      The function lseek64() is available since glibc 2.1, and is defined to be an alias for llseek().