Man pages › Compared with Linux and the BSDs

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

On Solnix, lex is the illumos lex at /usr/bin/lex, a separate implementation. On FreeBSD, lex is flex. The option sets differ. -w and -e mean EUC support on Solnix, but -w means 'suppress warnings' on FreeBSD, and Solnix has none of flex's long options or -s, -i, -l, -P, -o and -S.

The manual pages

Solnix: lex(1) from pkgs.solnix.illumos-world-man · illumos.org
FreeBSD: lex(1) 15.1-RELEASE
Standard: POSIX.1-2024 (IEEE Std 1003.1-2024), lex

What Solnix runs

A default Solnix system runs the illumos lex at /usr/bin/lex, published in pkgs.solnix.illumos-world-man. No other variants are shipped. The page does not say whether flex is available as a separate package.

Differences

Compared with	Topic	What differs
FreeBSD	implementation	Solnix lex is the illumos lex. FreeBSD lex is a name for flex, 'fast lexical analyzer generator', and the page documents flex options. Both write lex.yy.c by default. Source: Solnix lex(1) NAME, DESCRIPTION; FreeBSD lex(1) NAME, DESCRIPTION
FreeBSD	`-w` meaning	Solnix lex `-w` generates a program that handles EUC characters, with yytext[] as wchar_t[]. FreeBSD flex `-w` (`--nowarn`) suppresses warning messages. The same flag has unrelated effects. Source: Solnix lex(1) -w; FreeBSD lex(1) -w, --nowarn
FreeBSD	`-e` and EUC support	Solnix lex has `-e` for EUC characters, with yytext[] as unsigned char[]; it cannot be combined with `-w`. The FreeBSD synopsis and option list have no `-e`. Source: Solnix lex(1) SYNOPSIS, -e; FreeBSD lex(1) SYNOPSIS
FreeBSD	`-c` and `-n`	On Solnix, `-c` selects C-language actions (the default) and `-n` suppresses the `-v` statistics summary. On FreeBSD both are do-nothing, deprecated options kept for POSIX compliance. `-n` does not change FreeBSD output. Source: Solnix lex(1) -c, -n; FreeBSD lex(1) -c, -n
FreeBSD	`-v` statistics	Both write a statistics summary to standard error with `-v`. Solnix ties it to table sizes in the lex source: `-n` is implied if no sizes are given and `-v` is absent. FreeBSD's summary starts with the flex version and the flags used. Source: Solnix lex(1) -v, -n; FreeBSD lex(1) -v, --verbose
FreeBSD	Solnix-only options	Solnix has `-Q`[y\|n] to put version information into lex.yy.c (`-Qn` is the default), `-V` to print version information on standard error, and `-Y` directory for an alternate driver-file directory. The FreeBSD synopsis has no `-Q` or `-Y`. Source: Solnix lex(1) -Q, -V, -Y; FreeBSD lex(1) SYNOPSIS
FreeBSD	flex-only options	FreeBSD flex has `-s` (no default rule), `-i` (case-insensitive scanner), `-l` (AT&T lex compatibility mode), `-b`, `-d`, `-f`, `-F`, `-p`, `-B`, `-I`, `-C`, `-o` output, `-P` prefix and `-S` skeleton. The Solnix page documents none of these. Source: FreeBSD lex(1) SYNOPSIS, OPTIONS; Solnix lex(1) SYNOPSIS
FreeBSD	long options	FreeBSD flex accepts long options such as `--stdout`, `--verbose`, `--help` and `--version`. The Solnix page documents only single-letter options, so a script using `--stdout` for `-t` fails on Solnix. Source: FreeBSD lex(1) SYNOPSIS, -t --stdout; Solnix lex(1) SYNOPSIS, OPTIONS
FreeBSD	input files	On Solnix, several file operands are concatenated into one lex program, and a file operand of - means standard input, as does no operand. FreeBSD reads standard input when no file names are given; the visible text does not mention -. Source: Solnix lex(1) OPERANDS; FreeBSD lex(1) DESCRIPTION
FreeBSD	locale handling	Solnix says lex is not fully internationalized for regular expressions in the source or the generated analyzer. It lists LANG, LC_ALL, LC_COLLATE, LC_CTYPE, LC_MESSAGES and NLSPATH as affecting lex. The FreeBSD text in the bundle lists no environment variables. Source: Solnix lex(1) USAGE, ENVIRONMENT VARIABLES; FreeBSD lex(1) (no ENVIRONMENT section in bundle)
FreeBSD	exit status	Solnix lex returns 0 on success and >0 on error, and the state of lex.yy.c is unspecified after a non-zero exit. The FreeBSD text in the bundle does not document exit status. Source: Solnix lex(1) DESCRIPTION, EXIT STATUS; FreeBSD lex(1) (no EXIT STATUS in bundle)

Standards

POSIX: lex is a POSIX.1-2024 utility.
Solnix: Interface Stability: Standard. The page says generated C programs conform to the ISO C standard.
FreeBSD: -c and -n are described as do-nothing options included for POSIX compliance; -l gives maximum but not full compatibility with the original AT&T lex.

Writing portable scripts

Use only -t, -v and file operands in portable scripts. Redirect output yourself if you need a fixed name. Avoid -w, -e, -n and -c, which differ between illumos lex and flex.
Do not rely on long options, -s, -i, -l, -o or -P. They exist only in the FreeBSD flex text, not in the Solnix page.

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.