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From: guy@sun.uucp (Guy Harris)
Newsgroups: comp.unix.questions
Subject: Re: An awk question or two...
Message-ID: <28084@sun.uucp>
Date: Tue, 15-Sep-87 15:30:46 EDT
Article-I.D.: sun.28084
Posted: Tue Sep 15 15:30:46 1987
Date-Received: Thu, 17-Sep-87 06:43:53 EDT
References: <3931@well.UUCP> <27817@sun.uucp> <90@aimt.UUCP>
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Organization: Sun Microsystems, Inc. - Mtn View, CA
Lines: 24
Keywords: awk ranges

> Actually, according to: "Awk - A Pattern Scanning and Processing Language"
> by Aho Kernighan and Weinberger (Second Edition), "A variety of expressions
> may be used as patterns: regular expressions, arithmetic relational
> expressions, *string-valued expressions*, and arbitrary boolean
> combinations of these."  Now I haven't been able to make use of variables
> as "string-valued expressions" in the pattern part of an awk statement,
> but I haven't been able to find anything that says they can't be.

In the "awk" document in the S5R3 Programmer's Guide (I've found the S5 "awk"
documentation to be much nicer than the old documentation, and the S5R3 "awk"
isn't much changed from the "awk" that went out on the V7 addendum tape, which
is basically the same one that's in 4BSD), the list above is missing the
phrase "string-valued expressions".  Sounds like the documentation you cite
either 1) described a version of "awk" other than the one most people have or
2) has an error in it.

> I think the question boils down to, "How can I force awk to use the value of
> the variable: comvar instead of the string that is the variable's name?"

The answer is "you can't; sorry, the documentation lied".
-- 
	Guy Harris
	{ihnp4, decvax, seismo, decwrl, ...}!sun!guy
	guy@sun.com (or guy@sun.arpa)