YACC(1)                    OpenBSD Reference Manual                    YACC(1)

NAME
     yacc - an LALR(1) parser generator

SYNOPSIS
     yacc [-dlrtv] [-b prefix] [-o output_file] [-p symbol_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 options are as follows:

     -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 direc-
             tives in the generated code.  The #line directives let the C com-
             piler 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.

     -o output_file
             The -o option specifies an explicit name for the parser's output
             file name instead of the default.  The names of the other output
             files are constructed from output_file as described under the -d
             and -v options.

     -p symbol_prefix
             The -p option changes the prefix prepended to yacc-generated sym-
             bols to the string denoted by symbol_prefix.  The default prefix
             is the string yy.

     -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.c.

     -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 generat-
             ed parser to be written to the file y.output.

ENVIRONMENT
     TMPDIR  Name of directory where temporary files are to be 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-ze-
     ro.

FILES
     y.code.c
     y.tab.c
     y.tab.h
     y.output
     /tmp/yacc.aXXXXXXXXXX
     /tmp/yacc.tXXXXXXXXXX
     /tmp/yacc.uXXXXXXXXXX

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.

SEE ALSO
     yyfix(1)

STANDARDS
     The yacc utility conforms to IEEE Std 1003.2 (``POSIX.2'').

OpenBSD 3.5                      July 30, 1991                               2
