Man pages › Compared with Linux and the BSDs

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

On a default Solnix system expand is the illumos expand at /usr/bin/expand, documented on one page together with unexpand. It takes only -t tablist, plus the old -tabstop and -tab1,tab2,... forms. It has no GNU long options and no -i (Linux's --initial).

The manual pages

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

What Solnix runs

A default Solnix system runs the illumos expand at /usr/bin/expand. No other variants are shipped. The Solnix page also documents unexpand, which has -a and -t. The Linux, FreeBSD, OpenBSD and NetBSD pages in the bundle cover both commands except Linux, whose page covers expand only.

Differences

Compared with	Topic	What differs
Linux	`-i` / `--initial`	Linux expand has `-i` (`--initial`), which stops conversion of tabs after non-blank characters. The Solnix expand page documents no such option, only `-t` and the dash forms. Source: Linux expand(1) -i, --initial; Solnix expand(1) SYNOPSIS and OPTIONS
Linux	long options	Linux expand accepts `--tabs=N`, `--initial`, `--help` and `--version`. Solnix expand documents no long options, so scripts using `--tabs=` fail there. Source: Linux expand(1) -t, --tabs, --help, --version; Solnix expand(1) SYNOPSIS
Linux	tab list syntax	Linux `-t` LIST accepts a '/' prefix on the last position (tab size after the last stop) and a '+' prefix (relative to the last stop). The Solnix page documents neither. Source: Linux expand(1) -t, --tabs=LIST; Solnix expand(1) -t tablist
Linux	tab past the last stop	On Solnix, a tab past the last stop in a multi-stop list is replaced by one space. The Linux page says nothing about this case; it only offers the '/' and '+' prefixes for extending the list. Source: Solnix expand(1) -t tablist; Linux expand(1) -t, --tabs=LIST
Linux, FreeBSD, NetBSD	`-tabstop` and `-tab1`,tab2,... forms	Solnix expand accepts the tab stops as a dash-prefixed argument without `-t`, such as `-4` or `-4`,8,12. The Linux, FreeBSD and NetBSD pages document only `-t`. Source: Solnix expand(1) SYNOPSIS, -tabstop, -tab1,tab2,...,tabn; Linux/FreeBSD/NetBSD expand(1) SYNOPSIS
OpenBSD	dash form and repeated `-t`	OpenBSD also accepts a dash-prefixed tablist without `-t`, as Solnix does. OpenBSD alone documents repeating `-t` to set stops at those columns. Solnix passes the list as one `-t` argument separated by blanks or commas. Source: OpenBSD expand(1) -t tablist; Solnix expand(1) -t tablist
NetBSD	`-t` synopsis	The NetBSD synopsis shows expand with `-t` tabstop or `-t` tab1,...,tabn. The DESCRIPTION text describes the tab-stop semantics but has no OPTIONS entry for `-t`. Solnix gives a full `-t` entry with the ascending-order rule. Source: NetBSD expand(1) SYNOPSIS, DESCRIPTION; Solnix expand(1) -t tablist
OpenBSD	unexpand `-t`	Solnix unexpand supports `-t` tablist. OpenBSD unexpand does not: its synopsis is unexpand [`-a`], and its STANDARDS section says `-t` is not supported for unexpand. Source: Solnix unexpand -t tablist; OpenBSD unexpand(1) SYNOPSIS, STANDARDS
FreeBSD	unexpand `-a` with `-t`	On Solnix, giving `-t` makes unexpand ignore `-a`, and conversion is no longer limited to leading blanks. The FreeBSD synopsis shows `-a` and `-t` as alternatives, [`-a` \| `-t` ...], and its page does not describe this interaction. Source: Solnix unexpand(1) -t tablist; FreeBSD unexpand(1) SYNOPSIS, -a, -t
FreeBSD, OpenBSD, NetBSD	unexpand `-t` availability	The NetBSD synopsis lists unexpand `-t` and the FreeBSD synopsis lists it as an alternative to `-a`. Behaviour of `-t` with `-a` is described only in the Solnix page. Source: NetBSD unexpand(1) SYNOPSIS; FreeBSD unexpand(1) SYNOPSIS; Solnix unexpand(1) -t tablist
Linux	standard input operand	Linux documents that FILE of - reads standard input. The Solnix page says only that no file means standard input, and does not mention -. Source: Linux expand(1) DESCRIPTION; Solnix expand(1) DESCRIPTION, OPERANDS
Linux, OpenBSD, NetBSD	environment variables	Solnix lists LANG, LC_ALL, LC_CTYPE, LC_MESSAGES and NLSPATH. FreeBSD lists LANG, LC_ALL and LC_CTYPE. The Linux, OpenBSD and NetBSD pages in the bundle have no environment section. Source: Solnix expand(1) ENVIRONMENT VARIABLES; FreeBSD expand(1) ENVIRONMENT

Standards

POSIX: expand is a POSIX.1-2024 utility.
Solnix: Interface Stability: Standard. CSI: enabled.
FreeBSD: expand and unexpand conform to IEEE Std 1003.1-2001 (“POSIX.1”).
OpenBSD: Compliant with IEEE Std 1003.1-2008 (“POSIX.1”), except that unexpand has no -t flag. Giving tab stops without -t is not specified by that standard, though it states it “may be present in some implementations”.

Writing portable scripts

Use expand -t N or expand -t a,b,c with a comma-separated list. Avoid -i, --tabs and the dash forms such as -4, which only some systems accept.
Do not use unexpand -t in scripts that must run on OpenBSD, and do not combine it with -a: Solnix ignores -a when -t is given.

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.