# [texhax] verbatim environment problem

Barbara Beeton bnb at ams.org
Mon Feb 19 19:18:28 CET 2007

from don gingrich:

> I'm writing an explanatory text about Bourne shell scripting.
>
> I need to be able to use a lot of control characters in
> text I'm writing. I can usually get it to work but this has me
> stumped. Any suggestions gratefully apreciated.
[snip]
> \begin{alltt}
> 	ls .[^.]*
> \end{alltt}
> }}

from justin walker:

Martin may have the more correct answer (I haven't tried it).

Note that the 'uparrow' is a math symbol, so (La)TeX expects it to be
in a "math environment". Thus, as a simpler change, to avoid the
error, there are two approaches (the second being the one you want, I
think; but try them both):

ls .[$^$.]*

or

ls .[$\uparrow$.]*

since the ^ indicates a superscript, the first
suggestion will yield a complaint that it's
incomplete.  and the \uparrow isn't the same
shape.

here's a (plain tex) trick to get a character
"to print as itself" in a tt mode:

ls .[\char\^.]*

just precede the character in question with the
string "\char\"; it even works with backslashes.
-- bb