c++ - 在 C/C++ 中创建用零填充的 1GB 文件的最快方法是什么？

Question

我需要在 Windows 操作系统中创建一个充满零的巨大二进制文件。它的大小是给定的。在 C/C++ 中最有效的方法是什么？

Answer 1

尝试调用truncate(2):

truncate("/my/file", my_size);

更多信息，

man 2 truncate

The truncate() and ftruncate() functions cause the regular file named by path or referenced by fd to be truncated to a size of precisely length bytes.

If the file previously was larger than this size, the extra data is lost. If the file previously was shorter, it is extended, and the extended part reads as null bytes ('\0').

如果您正在寻找 Windows 原生功能，请查看 SetEndOfFile ，它的作用大致相同。