2008.08.23 16:07 "Re: [Tiff] creating sparse files......", by Bob Friesenhahn

Ehh. You do have to take into account that this was written in the module "tif_unix.c" or something like that. Wether this is active on Microsof operating systems as well, I don't know. Sounds like it should not be....

Probably "tif_unix.c" should really be called "tif_posix.c". It does actually work under Windows using Window's underscore-prefixed POSIX API equivalents. If you use the 'configure' based build under Cygwin or MinGW, then "tif_unix.c" will be used and "tif_unix.c" may be selected under Windows in other situations as well.

The Windows API documentation does not specify that intermediate bytes are automatically initialized to zero if you seek past the end of the file and write some data. The only WIN32 interface which is documented to extend the file while initializing with zero is chsize(), which is unfortunately limited to only 2GB due to the range of off_t under WIN32.

Bob
======================================
Bob Friesenhahn
bfriesen@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer, http://www.GraphicsMagick.org/