Man pages › Compared with Linux and the BSDs

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

flex is not in the Solnix base system; install pkgs.solnix.flex. The Solnix page is a short option summary (table compression and debugging only), while the FreeBSD page is the full manual. The most visible difference is that Solnix documents -v output as going to stdout, where FreeBSD documents stderr.

The manual pages

Solnix: flex(1) from pkgs.solnix.flex
FreeBSD: flex(1) 15.1-RELEASE

What Solnix runs

Not installed by default: add pkgs.solnix.flex. No other illumos variants are shipped. The Solnix page is dated May 2017 (The Flex Project) and refers readers to the Texinfo manual (`info flex`) for full documentation.

Differences

Compared with	Topic	What differs
FreeBSD	`-v` output stream	Solnix documents `-v` as writing the scanner statistics summary to stdout. FreeBSD documents it as writing to stderr. A script that captures or discards one stream may behave differently on the other system. Source: Solnix flex(1) -v, --verbose; FreeBSD flex(1) -v, --verbose
FreeBSD	`-s` long option name	The Solnix page spells the long form of `-s` as `--nodefault`. The FreeBSD page spells it `--no-default`. The short `-s` behaves the same on both: it suppresses the default ECHO rule. Source: Solnix flex(1) -s, --nodefault; FreeBSD flex(1) -s, --no-default
FreeBSD	`-t` / `--stdout` not documented on Solnix	FreeBSD documents `-t` (`--stdout`) to write the scanner to standard output instead of lex.yy.c. The Solnix page does not list `-t`, so the manual does not say how output is redirected there. Check `flex `--help`` after installing. Source: FreeBSD flex(1) -t, --stdout; Solnix flex(1) OPTIONS (no -t)
FreeBSD	options missing from the Solnix page	FreeBSD documents `-i` (case-insensitive), `-l` (lex compatibility), `-B` and `-I` (batch/interactive), `-h` and `-c`/-n (no-ops kept for POSIX). The Solnix page lists none of them. The manual does not say whether the Solnix flex accepts them. Source: FreeBSD flex(1) -i, -l, -B, -h, -c, -n; Solnix flex(1) DESCRIPTION
FreeBSD	synopsis and input handling	Solnix lists `flex [OPTIONS] [FILE]...` and does not say what happens with no file. FreeBSD documents reading standard input when no file is given, and generating lex.yy.c. FreeBSD's synopsis also shows `-o` output, `-P` prefix and `-S` skeleton. Source: Solnix flex(1) SYNOPSIS; FreeBSD flex(1) SYNOPSIS, DESCRIPTION
FreeBSD	lex name	The FreeBSD page is titled `flex, lex`, so lex is documented as a name for this program. The Solnix page names only flex. The manual does not say whether installing pkgs.solnix.flex provides a lex command. Source: FreeBSD flex(1) NAME; Solnix flex(1) NAME
FreeBSD	table compression options	Solnix documents the `-C` family (`-Ca`, `-Ce`, `-Cf`, `-CF`, `-Cm`, `-Cr`) and says `-Cem` is the default compression. FreeBSD's synopsis shows `-C`[aefFmr]. Both give `-f` as `-Cfr` and `-F` as `-CFr`. The visible FreeBSD text does not show its default. Source: Solnix flex(1) Table Compression; FreeBSD flex(1) SYNOPSIS, -f, -F
FreeBSD	debug and trace	Solnix lists `-T`/-`-trace` and `--hex` (hexadecimal instead of octal in debug output). Solnix describes `-d` only as 'enable debug mode in scanner'. FreeBSD describes the `-d` output as ``--accepting` rule at line N` lines on stderr, controlled by yy_flex_debug. Source: Solnix flex(1) Debugging (-d, -T, --hex); FreeBSD flex(1) -d

Standards

POSIX: flex is not a POSIX.1-2024 utility.
FreeBSD: -c and -n are described as do-nothing, deprecated options included for POSIX compliance.
Solnix: The Solnix page has no STANDARDS section.

Writing portable scripts

Use short options (-s, -v, -w, -d, -p) rather than long names; --nodefault and --no-default differ between the two pages.
Do not depend on which stream -v writes to: redirect both stdout and stderr if you parse the statistics.
On Solnix, check that flex is installed (pkgs.solnix.flex) before a build step calls it.

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.