NAME
yacc - an LALR(1) parser generator

SYNOPSIS
yacc [ -dlrtv ][ -b prefix ] filename

DESCRIPTION
Yacc reads the grammar specification in the file filename and
generates an LR(1) parser for it. The parsers consist of a set of
LALR(1) parsing tables and a driver routine written in the C
programming language. Yacc normally writes the parse tables and
the driver routine to the file y.tab.c.

The following options are available:

-b prefix The -b option changes the prefix prepended to the output
file names to the string denoted by prefix. The default
prefix is the character y.

-d The -d option causes the header file y.tab.h to be
written.

-l If the -l option is not specified, yacc will insert #line
directives in the generated code. The #line directives
let the C compiler relate errors in the generated code to
the user’s original code. If the -l option is specified,
yacc will not insert the #line directives. #line
directives specified by the user will be retained.

-r The -r option causes yacc to produce separate files for
code and tables. The code file is named y.code.c, and
the tables file is named y.tab.h.

-t The -t option changes the preprocessor directives
generated by yacc so that debugging statements will be
incorporated in the compiled code.

-v The -v option causes a human-readable description of the
generated parser to be written to the file y.output.

ENVIRONMENT
The following environment variable is referenced by yacc:

TMPDIR If the environment variable TMPDIR is set, the string
denoted by TMPDIR will be used as the name of the directory
where the temporary files are created.

TABLES
The names of the tables generated by this version of yacc are
"yylhs", "yylen", "yydefred", "yydgoto", "yysindex",
"yyrindex", "yygindex", "yytable", and "yycheck". Two
additional tables, "yyname" and "yyrule", are created if
YYDEBUG is defined and non-zero.

FILES
y.code.c
y.tab.c
y.tab.h
y.output
/tmp/yacc.aXXXXXX
/tmp/yacc.tXXXXXX
/tmp/yacc.uXXXXXX

DIAGNOSTICS
If there are rules that are never reduced, the number of such rules
is written to the standard error. If there are any LALR(1)
conflicts, the number of conflicts is also written to the standard
error.