Man pages › Compared with Linux and the BSDs

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

A default Solnix system runs the illumos yacc at /usr/bin/yacc, which has a small option set (-b -d -l -p -P -Q -t -v -V). The published Solnix page describes a different program, a GNU bison wrapper from pkgs.solnix.bison. Against FreeBSD's Berkeley Yacc, the biggest trap is -P: it selects a parser file on illumos but means reentrant parser on FreeBSD.

The manual pages

Solnix: yacc(1) from pkgs.solnix.bison
FreeBSD: yacc(1) 15.1-RELEASE
Standard: POSIX.1-2024 (IEEE Std 1003.1-2024), yacc

What Solnix runs

The published Solnix page (pkgs.solnix.bison) describes yacc as a simple wrapper around bison(1) that passes -y, --yacc for upward compatibility mode. The command on PATH by default is the illumos /usr/bin/yacc, which has its own options and behaviour. No other illumos variants are shipped. The bundle contains no Linux page, so no Linux comparison is made.

Differences

Compared with	Topic	What differs
FreeBSD	which program it is	Solnix's default yacc is the illumos yacc. FreeBSD's is Berkeley Yacc (page dated 2024-01-09). The published Solnix page describes a bison wrapper, which matches neither. Check which yacc is first on PATH before relying on any option. Source: Solnix yacc(1) DESCRIPTION (published, bison wrapper); Solnix default illumos yacc(1) NAME; FreeBSD yacc(1) NAME
FreeBSD	`-P` meaning	On Solnix's default yacc, `-P` parser names an alternative parser skeleton instead of `/usr/share/lib/ccs/yaccpar.` On FreeBSD, `-P` creates a reentrant parser (like %pure-parser) and takes no argument. Source: Solnix illumos yacc(1) -P; FreeBSD yacc(1) -P
FreeBSD	`-o` output file	FreeBSD yacc has `-o` output_file to name the parser file, and it overrides `-b`. The illumos yacc has no `-o`. Its only way to rename outputs is `-b` file_prefix, which gives file_prefix.tab.c, file_prefix.tab.h and file_prefix.output. Source: FreeBSD yacc(1) -o, -b; Solnix illumos yacc(1) -b, SYNOPSIS
FreeBSD	`-V` output stream	illumos yacc `-V` prints the version to standard error. FreeBSD yacc `-V` prints the version number to standard output. Capturing the version with $(yacc `-V`) works only on FreeBSD. Source: Solnix illumos yacc(1) -V; FreeBSD yacc(1) -V
FreeBSD	FreeBSD-only options	FreeBSD yacc accepts `-B`, `-g`, `-h`, `-H`, `-i`, `-L`, `-r`, `-s` and `-y`. The illumos yacc synopsis lists none of them. `-h` is a usage message and `-y` is ignored on FreeBSD. `-d` is the only header option on illumos. Source: FreeBSD yacc(1) SYNOPSIS and options -B -g -h -H -i -L -r -s -y; Solnix illumos yacc(1) SYNOPSIS
FreeBSD	`-Q` version stamping	The illumos yacc has `-Q`[y\|n]. `-Qy` puts version information in y.tab.c, and `-Qn` is the default and writes none. FreeBSD yacc documents no `-Q` option. Source: Solnix illumos yacc(1) -Q; FreeBSD yacc(1) SYNOPSIS
FreeBSD	`-t` debug code	On illumos, `-t` compiles runtime debugging code by default, and the YYDEBUG preprocessor symbol still controls it. On FreeBSD, `-t` changes the generated preprocessor directives, and debug output goes to standard output. The illumos page does not name the output stream. Source: Solnix illumos yacc(1) -t; FreeBSD yacc(1) -t
FreeBSD	grammar from stdin	FreeBSD yacc reads the grammar from standard input when the filename is a single '-', and honours '--' as end of options. The illumos page describes the operand only as a path name and does not mention either. Source: FreeBSD yacc(1) DESCRIPTION (last paragraph); Solnix illumos yacc(1) OPERANDS
FreeBSD	one yacc per directory	The illumos page warns that output file names are fixed, so at most one yacc process can be active in a directory at a time. The FreeBSD page gives no such warning but offers `-b` and `-o` to change the output names. Source: Solnix illumos yacc(1) NOTES; FreeBSD yacc(1) -b, -o
FreeBSD	locale and EUC handling	The illumos page documents LANG, LC_ALL, LC_CTYPE, LC_MESSAGES and NLSPATH. It also says EUC characters are handled as one-token symbols, and yylex() must return a wchar_t value for them. The FreeBSD page documents neither. Source: Solnix illumos yacc(1) ENVIRONMENT VARIABLES; FreeBSD yacc(1) (no ENVIRONMENT section)
FreeBSD	bison wrapper and `-y`	The published Solnix yacc is a bison wrapper and passes `-y`, `--yacc`, with options as in bison(1). FreeBSD yacc accepts `-y` but ignores it. It is described as present for ostensible POSIX compatibility with bison. Source: Solnix yacc(1) DESCRIPTION (published); FreeBSD yacc(1) -y

Standards

POSIX: yacc is a POSIX.1-2024 utility.
Solnix: illumos yacc ATTRIBUTES: Interface Stability is Committed; Standard is 'See standards(7)'.
FreeBSD: The FreeBSD page says POSIX (IEEE 1003.1 2004) documents only names and numbers for %token, though original yacc and bison also accept string literals. -s suppresses the extra #define to match original yacc behaviour.

Writing portable scripts

Stick to -b, -d, -l, -p, -t and -v, which appear in both the illumos and FreeBSD synopses. Do not use -o, -P, -V or -Q in portable scripts.
Run yacc in a separate directory per grammar, because the illumos output names are fixed (y.tab.c, y.tab.h, y.output). Use -b to give each grammar its own prefix.

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.