ipcs
display information about System V IPC resources
TLDR
Show all active IPC facilities
$ ipcs
Show active shared memory segments$ ipcs -m
Show active message queues$ ipcs -q
Show active semaphores$ ipcs -s
Show details for specific shared memory segment by ID$ ipcs -m -i [shmid]
Show system limits$ ipcs -l
Show summary of current usage$ ipcs -u
Show creator/owner information$ ipcs -c
Show last access times$ ipcs -t
SYNOPSIS
ipcs [options]
DESCRIPTION
ipcs displays information about System V IPC resources: shared memory segments, message queues, and semaphore arrays. It shows resource IDs, keys, owners, permissions, and sizes.This is essential for monitoring IPC resource usage and identifying orphaned resources that should be cleaned up with ipcrm.
PARAMETERS
-m, --shmems
Show shared memory segments-q, --queues
Show message queues-s, --semaphores
Show semaphore sets-i, --id ID
Show details for specific resource-l, --limits
Show system limits-u, --summary
Show usage summary-c, --creator
Show creator and owner UIDs/PIDs-p, --pid
Show PIDs of last operators-t, --time
Show last access times--human
Show sizes in human-readable format
INSTALL
sudo apt install util-linux
sudo dnf install util-linux
sudo pacman -S util-linux
sudo apk add util-linux-misc
sudo zypper install util-linux
brew install util-linux
nix profile install nixpkgs#util-linux
CAVEATS
Only shows System V IPC, not POSIX IPC resources. User can only see resources they have permission to access (root sees all). Large numbers of resources may indicate a leak.
HISTORY
ipcs has been a standard Unix utility since System V IPC was introduced in the early 1980s. It remains the primary tool for inspecting System V IPC resources.
