= Explicit client file management = The standard mode of file access on a BOINC client is: * '''Physical''' files exist in the projects/URL directory. BOINC keeps track of all physical files, and deletes them when no longer needed. * '''Logical''' files are links in the slots/N directory, and refer to physical files. Applications are free to create other files in their slot directory; BOINC doesn't know about these, other than to delete them when the app finishes. It's also possible for applications to create and access files in the project/URL directory. BOINC doesn't know about these files, and in particular it won't delete them until the user detaches your project. Some cases where you might want to do this: * Your application uses a large number of files, and you supply these as a single archive that is unpacked by your application (for example, using the [FileCompression#boinc-zip boinc_zip library]). If you store them in your project directory, you'll only need to do this unpacking once. * Your application generates a lot of files that are shared between workunits. In order to put files in the project directory, you need to know where it is. This can be found by calling [BasicApi#Communicatingwiththecoreclient boinc_get_init_data()]; the directory is in `APP_INIT_DATA.project_dir`.