w(1) on Solnix vs Linux and the BSDs

On Solnix, w is the illumos w at /usr/bin/w. It still takes the old -l, -s, -u and -w flags, which FreeBSD and OpenBSD say are no longer supported. -u and -i mean different things on Linux, and the BSDs have -i, -n and -M/-N, which Solnix lacks.

What Solnix runs

A default Solnix system runs the illumos w at /usr/bin/w. /usr/ucb/w is also shipped, but the bundle does not describe it.

Differences

Compared withTopicWhat differs
Linux-u meaningSolnix w -u prints the heading line (time, uptime, user count, load averages). Linux w -u (--no-current) ignores the username when working out the current process and CPU times. A Linux script using -u gets different behaviour on Solnix.
Source: Solnix w(1) -u; Linux w(1) -u, --no-current
FreeBSD, OpenBSD, NetBSD-u, -l, -s, -w acceptedSolnix accepts -l, -s, -u and -w. OpenBSD lists -f, -l, -s, -u and -w as no longer supported; FreeBSD lists -f, -l, -s and -w. NetBSD documents only -w, with a different meaning (see the -w entry).
Source: Solnix w(1) SYNOPSIS and OPTIONS; FreeBSD w(1) COMPATIBILITY; OpenBSD w(1) STANDARDS; NetBSD w(1) SYNOPSIS
FreeBSD, OpenBSD, NetBSD-i meaningSolnix w has no -i. On FreeBSD, OpenBSD and NetBSD, -i sorts the output by idle time. On Linux, -i (--ip-addr) shows the IP address instead of the hostname in the from field.
Source: Solnix w(1) SYNOPSIS; FreeBSD w(1) -i; OpenBSD w(1) -i; NetBSD w(1) -i; Linux w(1) -i, --ip-addr
Linux, NetBSD-w meaningSolnix w -w selects the long output form, which is also the default. On NetBSD, -w shows wide output without truncating any field. The Linux page has no -w.
Source: Solnix w(1) -w; NetBSD w(1) -w; Linux w(1) OPTIONS
Linux-s short formSolnix -s abbreviates the tty and leaves off the login time, both CPU times and command arguments. Linux -s (--short) leaves off only the login time, JCPU and PCPU. The Linux page does not say it drops arguments or abbreviates the tty.
Source: Solnix w(1) -s; Linux w(1) -s, --short
all fourremote host columnThe fields documented for Solnix w are login name, tty, login time, idle, JCPU, PCPU and command. No host column is listed. The Linux, FreeBSD, OpenBSD and NetBSD pages list a host (from) field. Linux prints it only with -f unless built otherwise.
Source: Solnix w(1) DESCRIPTION; FreeBSD/OpenBSD/NetBSD w(1) DESCRIPTION; Linux w(1) -f, --from
FreeBSD, OpenBSD, NetBSDaddress resolution flagsSolnix w has no -n or -a. FreeBSD and NetBSD -n show addresses numerically. OpenBSD -a does the opposite: it translates addresses into names.
Source: Solnix w(1) SYNOPSIS; FreeBSD w(1) -n; NetBSD w(1) -n; OpenBSD w(1) -a
FreeBSD, OpenBSD, NetBSDkernel image optionsFreeBSD, OpenBSD and NetBSD accept -M core and -N system to read kernel values from another core or system image. Solnix w documents no such options.
Source: FreeBSD w(1) -M, -N; OpenBSD w(1) -M, -N; NetBSD w(1) -M, -N; Solnix w(1) SYNOPSIS
Linux, FreeBSD, NetBSDoptions Solnix lacksLinux has long options and -c, -f, -o, -p, -t. FreeBSD has --libxo and -d. NetBSD has -A. Solnix w accepts only -h, -l, -s, -u, -w and an optional user.
Source: Linux w(1) OPTIONS; FreeBSD w(1) --libxo, -d; NetBSD w(1) -A; Solnix w(1) SYNOPSIS
Linuxenvironment variablesSolnix w documents LC_CTYPE, LC_MESSAGES and LC_TIME. Linux w documents PROCPS_CONTAINER, PROCPS_USERLEN and PROCPS_FROMLEN, which set container uptime and column widths. Solnix has no equivalents in its page.
Source: Solnix w(1) ENVIRONMENT VARIABLES; Linux w(1) ENVIRONMENT
FreeBSD, OpenBSD, NetBSDmultiple usersThe Solnix and OpenBSD SYNOPSIS lines take one optional user, as do Linux and NetBSD. FreeBSD's SYNOPSIS shows user ..., and its text says output is restricted to the named users.
Source: Solnix w(1) SYNOPSIS; FreeBSD w(1) SYNOPSIS; OpenBSD w(1) SYNOPSIS

Standards

  • POSIX: w is not a POSIX.1-2024 utility.
  • Solnix: The Solnix page has no STANDARDS section; the bundle states no standard for w.

Writing portable scripts

  • Use only -h and an optional user name in portable scripts; these are documented on Solnix, Linux, FreeBSD, OpenBSD and NetBSD. -i, -n, -s, -u and -w differ or are missing.
  • Do not parse w columns by position: the host column is documented on Linux and the BSDs but not on Solnix, and the Linux page says it is off by default. Use who(1) or the utmp data for structured needs.

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.