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YACC(1) NetBSD General Commands Manual YACC(1)
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yacc -- an LALR(1) parser generator
yacc [-dlrtv] [-b prefix] [-o outputfile] [-p symbol_prefix] filename
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
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.
The -o option specifies an explicit output file name should
be used instead of the default.
The -p option changes the prefix prepended to yacc-gener-
ated 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.
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 tempo-
rary files are created.
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-
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.
The yacc utility conforms to IEEE Std 1003.2 (``POSIX.2'').
NetBSD 5.0 July 30, 1991 NetBSD 5.0