Man pages › Compared with Linux and the BSDs

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

On Solnix, uname is the illumos uname, found at /usr/bin/uname and /sbin/uname. It has two options the other systems lack: -S sets the nodename and -X prints SCO-style expanded output. Solnix also discourages -m in favour of -p, which differs from the usual meaning of -m elsewhere.

The manual pages

Solnix: uname(1) from pkgs.solnix.illumos-world-man · illumos.org
Linux: uname(1) coreutils-full-9.11
FreeBSD: uname(1) 15.1-RELEASE
OpenBSD: uname(1) 8.0
NetBSD: uname(1) 11.0
Standard: POSIX.1-2024 (IEEE Std 1003.1-2024), uname

What Solnix runs

A default Solnix system runs the illumos uname at /usr/bin/uname and /sbin/uname. No other variants are shipped. The page comes from pkgs.solnix.illumos-world-man.

Differences

Compared with	Topic	What differs
all four	`-S` sets the nodename	Solnix uname `-S` system_name changes the nodename. Only the super-user may do it, and it does not persist across reboots. The Linux, FreeBSD, OpenBSD and NetBSD pages document no option that sets anything. Source: Solnix uname(1) SYNOPSIS, -S; Linux, FreeBSD, OpenBSD, NetBSD uname(1) SYNOPSIS
all four	`-X` expanded output	Solnix uname `-X` prints one element per line in the format SCO UNIX expects: system name, node, release, version, machine, CPU count, and more. BusType, Serial and Users are set to "unknown". None of the other pages document `-X`. Source: Solnix uname(1) -X; Linux, FreeBSD, OpenBSD, NetBSD uname(1) SYNOPSIS
FreeBSD, OpenBSD	`-m` versus `-p`	Solnix calls `-m` "machine hardware name (class)", discourages it, and says to use `-p` for the ISA or processor type. FreeBSD `-m` is the hardware platform and `-p` the processor architecture. OpenBSD `-m` is the kernel architecture and `-p` the application architecture. Source: Solnix uname(1) -m, -p, NOTES; FreeBSD uname(1) -m, -p; OpenBSD uname(1) -m, -p
all four	`-i` meaning	Solnix `-i` prints the platform name. Linux `-i` prints the hardware platform and marks it non-portable. FreeBSD `-i` prints the kernel ident. The OpenBSD and NetBSD pages have no `-i`. Source: Solnix uname(1) -i; Linux uname(1) -i, --hardware-platform; FreeBSD uname(1) -i; OpenBSD and NetBSD uname(1) SYNOPSIS
OpenBSD, NetBSD	`-o`	Solnix `-o` prints the name of the kernel/OS. Linux `-o` prints the operating system, and FreeBSD `-o` is a synonym for `-s`. The OpenBSD and NetBSD pages have no `-o`, so scripts using it fail there. Source: Solnix uname(1) -o; Linux uname(1) -o; FreeBSD uname(1) -o; OpenBSD and NetBSD uname(1) SYNOPSIS
all four	what `-a` prints	The Solnix page says `-a` prints "basic information currently available" and lists no fields. FreeBSD, OpenBSD and NetBSD define `-a` as `-m` `-n` `-r` `-s` `-v`. Linux omits `-p` and `-i` if unknown. Do not parse `-a` output by position. Source: Solnix uname(1) -a; FreeBSD uname(1) -a; OpenBSD uname(1) -a; NetBSD uname(1) -a; Linux uname(1) -a
FreeBSD	FreeBSD-only flags and environment	FreeBSD has `-b` (kernel build-id), `-K` (kernel version) and `-U` (user-environment version). Setting UNAME_ followed by a flag letter overrides the value. The Solnix page documents none of these. Source: FreeBSD uname(1) -b, -K, -U, ENVIRONMENT; Solnix uname(1) ENVIRONMENT VARIABLES
Linux	long options	Linux (GNU coreutils) accepts long options such as `--kernel-name`, `--nodename`, `--kernel-release`, `--machine`, plus `--help` and `--version`. The Solnix synopsis lists only single-letter options. Source: Linux uname(1) DESCRIPTION; Solnix uname(1) SYNOPSIS
OpenBSD	release string format	Solnix warns that release levels may be x.y.z (such as 5.5.1), not only x.y, so scripts must not assume two fields. OpenBSD documents the `-r` format as digit.digit. Source: Solnix uname(1) NOTES; OpenBSD uname(1) -r
FreeBSD, OpenBSD	multi-option output layout	FreeBSD and OpenBSD print all selected fields on one line separated by spaces when `-a` or several options are given. The Solnix page does not describe the layout of multi-option output, except that `-X` uses one element per line. Source: FreeBSD uname(1) DESCRIPTION; OpenBSD uname(1) DESCRIPTION; Solnix uname(1) OPTIONS
FreeBSD	arch and platform detection	Solnix NOTES say uname `-sp` gives hardware platform information and uname `-sr` gives OS name and release. It says arch `-k` and uname `-m` return equivalent values, and third-party programs should avoid both. Source: Solnix uname(1) NOTES

Standards

POSIX: uname is a POSIX.1-2024 utility.
Solnix: Interface Stability: Standard.
FreeBSD: The uname command is expected to conform to the IEEE Std 1003.2 (“POSIX.2”) specification.
OpenBSD: The uname utility is compliant with the IEEE Std 1003.1-2008 (“POSIX.1”) specification. The flag -p is an extension to that specification.
NetBSD: The uname utility conforms to IEEE Std 1003.2-1992 (“POSIX.2”). The -p option is an extension to the standard.

Writing portable scripts

Stick to -s, -n, -r, -v and -a without parsing its fields. These are documented on all five systems. Avoid -i, -o, -m and -p for portable logic, since they mean different things or are missing.
Do not assume the release string is x.y. Solnix says it could be x.y.z.

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.