I am using Ubuntu 20.
uname -a Linux peyman-Ubuntu 5.4.0-48-generic #52-Ubuntu SMP Thu Sep 10 10:58:49 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux when I use ipcs command , no semaphore arrays displayed. Is is possible that linux does nlot use semaphore arrays or problem is something else?
sudo ipcs -s ------ Semaphore Arrays -------- key semid owner perms nsems 1 Answer
There are no semaphore arrays because you haven't created any. A pair of shell commands to manage semaphore arrays and other System V inter-process communication (IPC) features is ipcmk and ipcrm.
For example
ipcmk --semaphore 3 # Create an array of three semaphores with id 0 And
ipcrm --semaphore-id 0 # Remove semaphore array with id 0 
