Man pages › Compared with Linux and the BSDs

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

The grep(1) page Solnix publishes is GNU grep, from pkgs.solnix.grep. The grep on PATH is the illumos grep at /usr/bin/grep, which has a much smaller option set. GNU-isms such as -P, -z, -m, --include and -a are not documented for it.

The manual pages

Solnix: grep(1) from pkgs.solnix.grep
Linux: grep(1) gnugrep-3.12
FreeBSD: grep(1) 15.1-RELEASE
OpenBSD: grep(1) 8.0
NetBSD: grep(1) 11.0
Standard: POSIX.1-2024 (IEEE Std 1003.1-2024), grep

What Solnix runs

/usr/bin/grep on a default Solnix system is illumos grep, not the GNU grep this page describes. GNU grep comes from pkgs.solnix.grep. /usr/xpg4/bin/grep is also shipped; the bundle does not describe how it differs. illumos grep documents -E, -F, -A/-B/-C, -b, -c, -e, -f, -h, -H, -i, -l, -L, -n, -o, -q, -r, -R, -s, -v, -w, -x and --label. In illumos grep, -b means block number, not byte offset, and -o cannot be combined with -v.

Differences

Compared with	Topic	What differs
all four	`-b` meaning (illumos default)	illumos `/usr/bin/grep` `-b` prints the block number of each matching line, starting at 0. GNU grep (Solnix package and Linux), FreeBSD, OpenBSD and NetBSD print a byte offset. Source: SOLNIX DEFAULT ON PATH illumos grep(1) -b; Solnix GNU grep(1) -b; Linux grep(1) -b; FreeBSD grep(1) -b; OpenBSD grep(1) -b; NetBSD grep(1) -b
all four	`-m` missing (illumos default)	illumos `/usr/bin/grep` has no `-m` (stop after NUM matches). GNU grep, FreeBSD, OpenBSD and NetBSD all have it. Source: SOLNIX DEFAULT ON PATH illumos grep(1) SYNOPSIS; Linux grep(1) -m; FreeBSD/OpenBSD/NetBSD grep(1) option lists
Linux, FreeBSD, NetBSD	common extensions missing (illumos default)	illumos `/usr/bin/grep` does not document `-a`/-`-text`, `-I`, `-z`/-`-null-data`, `-Z`/-`-null`, `--include`, `--exclude` or `--color`. GNU grep documents all of them, and FreeBSD and NetBSD document most of them. Source: SOLNIX DEFAULT ON PATH illumos grep(1) SYNOPSIS, OPTIONS; Solnix GNU grep(1) OPTIONS; FreeBSD grep(1) -a, -I, --include; NetBSD grep(1) -a, -I, --include
Linux	`-P` (Perl regex)	GNU grep (Solnix package and Linux) has `-P` for Perl-compatible regular expressions. illumos `/usr/bin/grep` does not, and neither do the FreeBSD, OpenBSD or NetBSD option lists. Source: Solnix GNU grep(1) -P; Linux grep(1) -P; SOLNIX DEFAULT ON PATH illumos grep(1) SYNOPSIS
OpenBSD	`-Z` meaning	OpenBSD grep `-Z` makes grep behave as zgrep and read compressed input. In GNU grep (Solnix package and Linux), `-Z` means `--null`: write a NUL byte after file names. illumos `/usr/bin/grep` has no `-Z`. Source: OpenBSD grep(1) -Z; Solnix GNU grep(1) -Z, --null; Linux grep(1) -Z
all four	`-o` with `-v` (illumos default)	illumos `/usr/bin/grep` does not support `-o` together with `-v`. The GNU, FreeBSD, OpenBSD and NetBSD pages state no such limit. Source: SOLNIX DEFAULT ON PATH illumos grep(1) -o; Linux grep(1) -o; FreeBSD/OpenBSD/NetBSD grep(1) -o
FreeBSD	`-r` vs `-R`	In illumos `/usr/bin/grep`, `-r` skips symlinks found while recursing and skips devices, FIFOs and sockets; `-R` follows all symlinks. The FreeBSD page describes `-r` and `-R` as having the same effect. Source: SOLNIX DEFAULT ON PATH illumos grep(1) -r, -R; FreeBSD grep(1) -d
OpenBSD	`-C` default	OpenBSD grep takes `-C`[num] with an optional argument, defaulting to 2, and no space is allowed before the number. illumos and GNU grep take `-C` num (or `-num`) with a required number. Source: OpenBSD grep(1) -C; SOLNIX DEFAULT ON PATH illumos grep(1) -C; Solnix GNU grep(1) -C
FreeBSD, NetBSD	colour variable	GNU grep (Solnix package and Linux) reads colours from GREP_COLORS. FreeBSD and NetBSD read GREP_COLOR. Source: Solnix GNU grep(1) --color; FreeBSD grep(1) --colour; NetBSD grep(1) --colour
Linux	same program as Linux	The published Solnix page and Linux both describe GNU grep (Linux: gnugrep-3.12), so the options match once pkgs.solnix.grep is installed and first on PATH. Source: Header COUNTERPART linux; Solnix grep(1) and Linux grep(1) OPTIONS

Standards

POSIX: grep is a POSIX.1-2024 utility.
OpenBSD: The grep utility is compliant with the IEEE Std 1003.1-2008 (“POSIX.1”) specification. The flags [-AaBbCGHhILmoRUVwZ] are extensions to that specification.

Writing portable scripts

Stick to -E, -F, -c, -e, -f, -i, -l, -n, -q, -s, -v and -x. These are the options that illumos, GNU and BSD grep all document with the same meaning.
Do not use -b for byte offsets: illumos /usr/bin/grep prints block numbers.
If a script needs GNU options (-P, -z, --include, -m), install pkgs.solnix.grep and call that grep explicitly instead of relying on /usr/bin/grep.

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.