.\" SCCSID: @(#)yacc.1	8.1	9/11/90.\" SCCSID: @(#)yacc.1	8.1	9/11/90.TH yacc 1 .SH Nameyacc \- yet another compiler-compiler.SH Syntax.B yacc[\fB\-vd\fR] \fIgrammar\fR.SH Description.NXR "yacc compiler".NXA "yacc compiler" "lex program generator".NXR "compiler" "creating"The.PN yacccommand converts a context-free grammar into a set oftables for a simple automaton which executes anleft recursive parsing algorithm.The grammar may be ambiguous;specified precedence rules are used to break ambiguities..PPThe output file, .PN y.tab.c ,must be compiled by the C compilerto produce a program.IR yyparse .This program must be loaded with the lexical analyzer program,.IR yylex ,as well as.I mainand.IR yyerror ,an error handling routine.These routines must be supplied by the user; .PN lex(1)is useful for creating lexical analyzers usable by.PN yacc ..SH Options.IP \fB\-d\fR 0.3iWrites all define statements to .PN y.tab.hfile.  This allows source files other than .PN y.tab.cto access the token codes..IP \fB\-v\fR 0.3iWrites description of parsing tables and reportof grammatical conflicts to.PN y.outputfile.  .SH DiagnosticsThe number of reduce-reduce and shift-reduce conflictsis reported on the standard output;a more detailed report isfound in the .PN y.output file .Similarly, if some rules are not reachable from thestart symbol, this is also reported..SH RestrictionsBecause file names are fixed, at most one.PN yaccprocess can be active in a given directory ata time..SH Files.ta \w'yacc.tmp, yacc.acts 'uy.output.bry.tab.c.bry.tab.h	defines for token names.bryacc.tmp, yacc.acts	temporary files.SH See Alsolex(1).br"YACC \- Yet Another Compiler Compiler".I ULTRIX Supplementary DocumentsVol. II:Programmer