NAME    [Toc]    [Back]

     yacc - an LALR(1) parser generator

SYNOPSIS    [Toc]    [Back]

     yacc   [-dlrtv]   [-b   prefix]   [-o    output_file]    [-p
symbol_prefix] filename

DESCRIPTION    [Toc]    [Back]

     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 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.

     -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  yaccgenerated symbols
  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 generated
 parser to be written to the file y.output.

ENVIRONMENT    [Toc]    [Back]

     TMPDIR   Name  of  directory where temporary files are to be
created.

TABLES    [Toc]    [Back]

     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    [Toc]    [Back]

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

DIAGNOSTICS    [Toc]    [Back]

     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    [Toc]    [Back]

     yyfix(1)

STANDARDS    [Toc]    [Back]

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

OpenBSD      3.6                           July      30,     1991