Man pages › Compared with Linux and the BSDs

`ipcs(1)` on Solnix vs Linux and the BSDs

On Solnix, ipcs is the illumos ipcs at /usr/bin/ipcs, with an /usr/xpg4/bin/ipcs variant. It reports System V IPC like the Linux and BSD tools, but adds zone and project options (-z, -Z, -J) and has no Linux -l/-u/-i id or BSD -M/-Q/-S/-T system-information flags.

The manual pages

Solnix: ipcs(1) from pkgs.solnix.illumos-world-man · illumos.org
Linux: ipcs(1) util-linux-2.42.3
FreeBSD: ipcs(1) 15.1-RELEASE
OpenBSD: ipcs(1) 8.0
NetBSD: ipcs(1) 11.0
Standard: POSIX.1-2024 (IEEE Std 1003.1-2024), ipcs

What Solnix runs

A default Solnix system runs the illumos ipcs at /usr/bin/ipcs. /usr/xpg4/bin/ipcs is also shipped. The bundle shows the same page for both and does not describe any difference between them.

Differences

Compared with	Topic	What differs
Linux	`-a` meaning	On Solnix, `-a` is shorthand for `-b` `-c` `-o` `-p` `-t`, and with no `-m`/-q/-s it applies to all three facility types. On Linux, `-a` means all three resources and is the default; the Linux page says it does not support the POSIX `-a`, `-b` and `-o` options. Source: Solnix ipcs(1) -a; Linux ipcs(1) -a, --all, CONFORMING TO
Linux	`-b` and `-o`	Solnix supports the POSIX `-b` (maximum sizes) and `-o` (outstanding usage) as print options. The Linux page says it does not support them. On Linux, `-b` only changes `-l` output to bytes. Source: Solnix ipcs(1) -b, -o; Linux ipcs(1) -b, --bytes, CONFORMING TO
Linux	`-i` meaning	Solnix `-i` prints the number of ISM attaches to shared memory segments. Linux `-i` id shows full details for one resource element and must be combined with `-m`, `-q` or `-s`. A Linux script using `-i` id fails or misbehaves on Solnix. Source: Solnix ipcs(1) -i, ISMATTCH; Linux ipcs(1) -i, --id
Linux	`-l`, `-u` and long options	Solnix has no `-l` (limits) or `-u` (summary), and the Solnix page lists no GNU-style long options. Linux provides `-l`/-`-limits`, `-u`/-`-summary`, `--human` and others, and says portable applications shall not use `-l` and `-u`. Source: Solnix ipcs(1) SYNOPSIS; Linux ipcs(1) -l, -u, --human, CONFORMING TO
Linux	output formats: last one wins	On Linux, of `-c`, `-l`, `-p`, `-t` and `-u` only the last one specified takes effect. Solnix print options (`-b`, `-c`, `-o`, `-p`, `-t` and so on) are combinable, and `-a` and `-A` are shorthands for several of them. Source: Linux ipcs(1) Output formats; Solnix ipcs(1) -a, -A
FreeBSD, OpenBSD, NetBSD	system information flags `-M` `-Q` `-S` `-T`	FreeBSD, OpenBSD and NetBSD have `-M`, `-Q`, `-S` and `-T` to show system-wide information about shared memory, message queues and semaphores. Solnix has none of these. Its SYNOPSIS lists only `-aAbciJmopqstZ`, `-D` and `-z`. Source: FreeBSD/OpenBSD/NetBSD ipcs(1) -M, -Q, -S, -T; Solnix ipcs(1) SYNOPSIS
FreeBSD, OpenBSD	`-C` and `-N` kernel sources	FreeBSD and OpenBSD take `-C` core and `-N` system to read from a core file and name list. FreeBSD also has `-y` for kvm(3) instead of sysctl(3). The Solnix page documents none of these. Source: FreeBSD ipcs(1) -C, -N, -y; OpenBSD ipcs(1) -C, -N; Solnix ipcs(1) SYNOPSIS
FreeBSD	`-u` user filter	FreeBSD `-u` user shows only IPC objects owned by that user. Solnix has no user filter. Its `-z` limits output by zone, not by user. Source: FreeBSD ipcs(1) -u; Solnix ipcs(1) -z
all four	zones and projects	Solnix `-z` zone selects a zone by name or numeric id, `-Z` lists all zones from the global zone, and `-J` prints the creator's project. None of the counterpart pages documents zone or project options. Source: Solnix ipcs(1) -z, -Z, -J; Linux/FreeBSD/OpenBSD/NetBSD ipcs(1) OPTIONS
all four	`-D` message dump	Solnix `-D` mtype shows the contents of messages of the given type, in hexadecimal and ASCII, from queues the user can read. No counterpart page documents an equivalent option. Source: Solnix ipcs(1) -D; Linux/FreeBSD/OpenBSD/NetBSD ipcs(1) OPTIONS
FreeBSD, OpenBSD, NetBSD	column documentation	The FreeBSD, OpenBSD and NetBSD pages say they do not explain the printed columns. The Solnix page documents the column headings and the 11-character MODE field, so use it for reference. Source: FreeBSD/OpenBSD/NetBSD ipcs(1) BUGS; Solnix ipcs(1) column headings, MODE
Linux	data source	Linux ipcs parses `/proc/sysvipc`, and falls back to IPC_STAT calls when `/proc` is unavailable. The Solnix page does not say how it gathers its data. Source: Linux ipcs(1) NOTES; Solnix ipcs(1) DESCRIPTION

Standards

POSIX: ipcs is a POSIX.1-2024 utility.
Linux: The Linux ipcs utility is not fully compatible to the POSIX ipcs utility. It does not support the POSIX -a, -b and -o options, but supports the -l and -u options not defined by POSIX.
OpenBSD: The ipcs utility is compliant with the X/Open System Interfaces option of the IEEE Std 1003.1-2008 (“POSIX.1”) specification. The flags [-CMNQST] are extensions to that specification.

Writing portable scripts

Stick to -m, -q, -s and -a/-b/-c/-o/-p/-t for portability, and avoid -a, -b and -o on Linux, where they are not POSIX-compatible.
Do not use -i, -l, -u, -M, -Q, -S, -T, -C, -N, -y, -z, -Z or -J in portable scripts. Each exists on only some of the systems.

Every difference here is taken from the manual pages linked above: Solnix's published page, Linux (man-pages and the GNU and util-linux manuals), FreeBSD, OpenBSD and NetBSD. Each row names its source. Where a manual is silent, this page is too. Compiled 2026-10-26. Found a mistake? Mail hackers@lists.solnix.io.