# [OS X TeX] help

Thu Feb 28 22:54:10 EST 2008

```On Feb 28, 2008, at 10:39 PM, ludwik kowalski wrote:

> On Feb 28, 2008, at 9:56 PM, Ari Stern wrote:
>
>>> 2) Using TexShop I am composing an input.tex file. The file is long
>>> because I pasted a long text into it. Here what I would like to be
>>> able to do (but do not know how). Suppose I select a large number of
>>> lines. Is there a command for placing the % sign in front of each of
>>> them at once? Then I would select a small set of commands and remove
>>> the % from them before pressing the "typeset" button. That would be
>>> useful in debugging.
>>
>> If you want TeX to ignore a whole block of text, there's an
>> alternative to commenting the individual lines out:
>>
>> \iffalse
>> [... block of text to ignore ...]
>> \fi
>>
>> I find this useful for debugging, as well as when I want to rewrite a
>> passage, but don't want to delete my original draft from the source.
>
>
> 1) I suppose that [ ...... ] stands for a sequence of lines to be
> commented and that square brackets are not needed.
> 2) But what has to be false ? In other words, under what conditions
> will the block of lines be ignored by the compiler?
> 3)  When I commented a block of lines they were ignored
> unconditionally. What Ari is proposing seems to be different in
> that respect. Right or wrong?
>

I actually prefer the regular commenting out, i.e. line by line, but
always true. I.e. the moment you add the words \iffalse and \fi
there, the stuff inbetween will not be taken into account.

Another approach, which I used to like to take, is to have something
like:

\commentout{
.....text to ignore...
}

And to have at the beginning of your document something like:
\newcommand{\commentout}[1]{}

But the commenting out is preferable in my opinion, especially if you
are using a text editor that shows commented out text very clearly
different from the rest. TextMate is my personal preference.
>
> Ludwik Kowalski, a retired physicist
> 5 Horizon Road, apt.2702, Fort Lee, NJ, 07024, USA
> Also an amateur journalist at http://csam.montclair.edu/~kowalski/cf/
>
>