Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!cs.utexas.edu!uunet!stanford.edu!shap@shasta.Stanford.EDU
From: shap@shasta.Stanford.EDU (shap)
Newsgroups: comp.lang.c
Subject: Re: using lex with strings, not files
Keywords: lex, yacc, strings
Message-ID: <187@shasta.Stanford.EDU>
Date: 6 May 91 18:43:37 GMT
References: <5384@lectroid.sw.stratus.com>
Organization: Stanford University Computer Systems Laboratory
Lines: 15

In article <5384@lectroid.sw.stratus.com> leavitt@mordor.hw.stratus.com (Will Leavitt) writes:
>
>   I'd like to use lex & yacc to parse strings within an application, but they
>seem to be hardwired to take their input from stdin.  What is the cannonical 
>way to get them to work on a string?  Thanks!

Yacc doesn't read the input directly, so there's no work there.  My
recollection is that lex uses two macros: GET() and UNGET() to
obtain/pushback characters.  If you take a look at the lex-generated C
code you will spot them. 

What you need to do is supply your own version of these macros at teh
top of your file.

Jonathan