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From: ronald@atcmp.nl (Ronald Pikkert)
Newsgroups: comp.unix.questions
Subject: Re: Lex and redefining the i/o macros
Message-ID: <636@atcmpe.atcmp.nl>
Date: 16 Jul 90 09:19:16 GMT
References: <859@airgun.wg.waii.com>
Organization: AT Computing, Nijmegen, The Netherlands
Lines: 29

From article <859@airgun.wg.waii.com>, by lampshir@airgun.wg.waii.com (gregory b. lampshir):


<> char input()
<> {
<> 	int pos;
<> 	char *ch;  
<> 	
<> 	pos=read(filePointerIn,ch,1);
<>  	if(pos==0) return(0); /* needed by lex to signal eof */
<> 	else return(*ch);
<> }
<> 
<> Can any of you lex wizards help me with this one?  What am I doing wrong?

How about initialising the pointer ch? Or just write something like:

 	char ch;  
 	if (read(filePointerIn,&ch,1)!=1) return(0);
  	return(ch);

By the way, how about not using a system call for every single character 
that is to be read?

-
Ronald Pikkert                 E-mail: ronald@atcmp.nl
@ AT Computing b.v.            Tel:    080 - 566880
Toernooiveld
6525 ED  Nijmegen