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From: lgy@pupthy2.PRINCETON.EDU (Larry Yaffe)
Newsgroups: comp.unix.wizards
Subject: Re: #defines with variable # arguments
Summary: m4 suggestion: close, but not perfect
Message-ID: <2918@phoenix.Princeton.EDU>
Date: 16 May 88 00:53:10 GMT
References: <2855@phoenix.Princeton.EDU+ <2633@tekcrl.TEK.COM> <979@cresswell.quintus.UUCP> <980@cresswell.quintus.UUCP>
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From: lgy@pupthy2.PRINCETON.EDU (Larry Yaffe)
Newsgroups: comp.unix.wizards
Subject: Re: #defines with variable # arguments
Summary: m4 suggestion: close, but not perfect
Message-ID: <2918@phoenix.Princeton.EDU>
Date: 16 May 88 00:53:10 GMT
References: <2855@phoenix.Princeton.EDU+ <2633@tekcrl.TEK.COM> <979@cresswell.quintus.UUCP> <980@cresswell.quintus.UUCP>
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Reply-To: lgy@pupthy2.PRINCETON.EDU (Larry Yaffe)
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Organization: Physics Dept, Princeton Univ

In article <980@cresswell.quintus.UUCP> ok@quintus.UUCP (Richard A. O'Keefe) writes:
    [Using m4 to process macros with variable # arguments]

-I should substantiate that.
-
-If you just want to make the BSD sprintf() look as though it returned an
-integer, do
-
-cat >sprintflen.m4 <<'EOF'
-define(sprintf,`strlen(`sprintf'($*))')dnl
-EOF

    This was definitely a helpful suggestion - not being overly familiar
with m4, I hadn't considered using it.  However, the suggested m4 scripts
suffer from two small problems:

    Whitespace between the "sprintf" and the following argument list must
first be removed in order for m4 to process the arguments correctly.
This is easily accomplished using 'sed'.

    Argument lists containing unmatched quoted parentheses, such as,
sprintf (str,"= ("),  produce horrible garbage.  This is a real occurence
in some of the source I'm dealing with.  (However, having to edit a
handful of special sprintf's by hand is a big improvement over having
to edit hundreds.)

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Laurence G. Yaffe			Internet: lgy@pupthy.princeton.edu
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