On Tue, Oct 13, 2009 at 3:26 PM, Eric Niebler <eric@boostpro.com> wrote:

Roland Bock wrote:

Eric Niebler wrote:

Forgive me for the n00b-ish (and slightly offtopic) question, but is there any way in standard C++ or in Boost.Filesystem to truncate a file to a particular size? With std::ofstream, I can either truncate a file on open to 0 size, or else open it in overwrite mode and scribble over it, but when I'm done, I don't seem to have a way of saying, "The end of the file is now *here*." Is that right? And if so, does Boost.Filesystem have an API for this?

There are two posix functions ("truncate" and "ftruncate") which might do what you need.

It doesn't look like these functions exist for MSVC users. So it seems there is no portable way to change the size of a file. Beman, would this make a good addition to the filesystem library?