From:	Tron Thomas <tron DOT thomas AT sierra DOT com>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Can't get YACC parser to run
Date:	Thu, 05 Jun 1997 11:06:56 -0700
Organization:	Sierra On-Line
Lines:	23
Message-ID:	<33970040.7AF0@sierra.com>
NNTP-Posting-Host:	198.107.212.165
Mime-Version:	1.0
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

I reading the book "Lex and Yacc" by John R. Levine, Tonay Mason, and
Doug Brown.  I am using Flex version 2.5.3 and Bison version 1.25 for
MS-DOS to run their examples, and I'm compiling the programs using
Visual C++ 4.2 on Windows '95.

I created the program in example 1-7 (a Yacc Parser) of chapter one, but
I'm not sure how I'm supposed to run it.  When I just try to launch it,
the program crashes.  This is because the main function in the file
ch1-05.y is defined as follows:

extern FILE *yyin;

main( )
{
	while(!feof(yyin)){
		yyparse( );
	}
}

When I trace through this code yyin = 0 causing the program to crash on
the call to feof.

Can somebody tell me what I need to do to get this program to run?

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