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From: eijkhout@s41.csrd.uiuc.edu (Victor Eijkhout)
Newsgroups: comp.text.tex
Subject: Re: TeX program that prints itself when typeset
Message-ID: <1991May16.001940.24144@csrd.uiuc.edu>
Date: 16 May 91 00:19:40 GMT
References: <3560@wn1.sci.kun.nl>
Sender: news@csrd.uiuc.edu (news)
Organization: UIUC Center for Supercomputing Research and Development
Lines: 18

sommel@sci.kun.nl (Ron Sommeling) writes:

>Below is a small plain TeX program that will print itself (in typewriter
>font without pagenumber) when typeset. Are there shorter solutions?

>\output{}\def\do#1{\catcode`#112}\def\t{\dospecials\obeylines\tt~}
>\def~#1^^:{#1#1^^:\end}\t
>\output{}\def\do#1{\catcode`#112}\def\t{\dospecials\obeylines\tt~}
>\def~#1^^:{#1#1^^:\end}\tz

>Ron Sommeling <sommel@sci.kun.nl>

Very cute, Ron. Here's a one-liner (albeit a rather long line :-)
that doesn't print itself, but it \message's itself.

\def \a #1{\let \#\relax \let \a \relax \message {#1\catcode `\#=12 \a {#1}}}\catcode `\#=12 \a {\def \a #1{\let \#\relax \let \a \relax \message {#1\catcode `\#=12 \a {#1}}}}

Victor.