The File Descriptor Management services are supplied by the logical file system for creating, using, and maintaining file descriptors. These services allow for the implementation of system calls that use a file descriptor as a parameter, create a file descriptor, or return file descriptors to calling applications. The following are the File Descriptor Management services:
| ufdcreate | Allocates and initializes a file descriptor. |
| ufdhold | Increments the reference count on a file descriptor. |
| ufdrele | Decrements the reference count on a file descriptor. |
| ufdgetf | Gets a file structure pointer from a held file descriptor. |
| getufdflags | Gets the flags from a file descriptor. |
| setufdflags | Sets flags in a file descriptor. |