Make a subdirectory of an archive its root directory.
Defined in <physfs.h>
int PHYSFS_setRoot(const char *archive, const char *subdir);| const char * | archive | dir/archive on which to change root. |
| const char * | subdir | new subdirectory to make the root of this archive. |
(int) Returns nonzero on success, zero on failure. Use PHYSFS_getLastErrorCode() to obtain the specific error.
This lets you narrow down the accessible files in a specific archive. For example, if you have x.zip with a file in y/z.txt, mounted to /a, if you call PHYSFS_setRoot("x.zip", "/y"), then the call PHYSFS_openRead("/a/z.txt") will succeed.
You can change an archive's root at any time, altering the interpolated file tree (depending on where paths shift, a different archive may be providing various files). If you set the root to NULL or "/", the archive will be treated as if no special root was set (as if the archive was just mounted normally).
Changing the root only affects future operations on pathnames; a file that was opened from a path that changed due to a setRoot will not be affected.
Setting a new root is not limited to archives in the search path; you may set one on the write dir, too, which might be useful if you have files open for write and thus can't change the write dir at the moment.
It is not an error to set a subdirectory that does not exist to be the root of an archive; however, no files will be visible in this case. If the missing directories end up getting created (a mkdir to the physical filesystem, etc) then this will be reflected in the interpolated tree.
It is safe to call this function from any thread.
This function is available since PhysicsFS 3.1.0.