Question

In linux I can get the list of opened posix shared memory segments by getting /dev/shm directory listing.

How do I programmatically get list of all opened posix shared memory segments in FreeBSD?
Assuming segments opened with shm_open() and I don’t know even a part of a name that was used as a first argument of shm_open().

Answer 1

You can’t. See the comment in /sys/kern/uipc_shm.c:

 * TODO:
 *
 * (2) Need to export data to a userland tool via a sysctl.  Should ipcs(1)
 *     and ipcrm(1) be expanded or should new tools to manage both POSIX
 *     kernel semaphores and POSIX shared memory be written?
 *
 * (3) Add support for this file type to fstat(1).