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
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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?