.\" Copyright (c) 1989 The Regents of the University of California.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to Berkeley by
.\" Robert Paul Corbett.
.\"
.\" Redistribution and use in source and binary forms are permitted
.\" provided that the above copyright notice and this paragraph are
.\" duplicated in all such forms and that any documentation,
.\" advertising materials, and other materials related to such
.\" distribution and use acknowledge that the software was developed
.\" by the University of California, Berkeley.  The name of the
.\" University may not be used to endorse or promote products derived
.\" from this software without specific prior written permission.
.\" THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
.\" IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
.\"
.\"	@(#)yacc.1	5.3 (Berkeley) 05/12/90
.\"
.TH YACC 1 ""
.UC 7
.SH NAME
yacc \- an LALR(1) parser generator
.SH SYNOPSIS
.B yacc [ -dltv ] [ -b
.I prefix
.B ]
.I filename
.SH DESCRIPTION
.I Yacc
reads the grammar specification in the file
.I 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.
.I Yacc
normally writes the parse tables and the driver routine to the file
.IR y.tab.c.
.PP
The following options are available:
.RS
.TP
\fB-b \fIprefix\fR
The
.B -b
option changes the prefix prepended to the output file names to
the string denoted by
.IR prefix.
The default prefix is the character
.IR y.
.TP
.B -d
The \fB-d\fR option causes the header file
.IR y.tab.h
to be written.
.TP
.B -l
If the
.B -l
option is not specified,
.I 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 \fB-l\fR option is specified,
.I yacc
will not insert the \#line directives.
Any \#line directives specified by the user will be retained.
.TP
.B -t
The
.B -t
option will change the preprocessor directives generated by
.I yacc
so that debugging statements will be incorporated in the compiled code.
.TP
.B -v
The
.B -v
option causes a human-readable description of the generated parser to
be written to the file
.IR y.output.
.RE
.PP
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.
.SH TABLES
The names of the tables generated by this version of
.I 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.
.SH FILES
.IR y.tab.c
.br
.IR y.tab.h
.br
.IR y.output
.br
.IR /tmp/yacc.aXXXXXX
.br
.IR /tmp/yacc.tXXXXXX
.br
.IR /tmp/yacc.uXXXXXX
.SH "SEE ALSO"
yyfix(1)
.SH DIAGNOSTICS
If there are rules that are never reduced, the number of such rules is
reported on standard error.
If there are any LALR(1) conflicts, the number of conflicts is reported
on standard error.