My understanding is that a file descriptor is an integer which is a key in the kernel's per-process mapping to objects such as
open()ed files, pipes, sockets, etc.
Is there a proper, short, and specific name for “open files/sockets/pipes/...”, the referents of file descriptors?
Calling them “files” leads to confusion with unopened files stored in the file system. Simply referring to file descriptors does not adequately describe the semantics (e.g. copying the integer between processes is useless).
Consulting The Open Group Base Specifications and my own system's manpages leads me to the conclusion that the referent of a file descriptor is an object and when it is specifically an open file it is, well, an open file. Is there a more specific term than object?