[OS X TeX] Regular expressions

[Maarten Sneep]

On May 12, 2007, at 10:58, André Bellaïche wrote:

> With the OgreKit search panel from TeXShop, we can search in the  
> text for regular expressions.
>
> But I could not find what is the good syntax to search for  
> expressions involving a macro, such as \index{*} (where * stands  
> for any character string).
>
> Can somebody|anybody give me a hand ?

Install TextWrangler, and read the Grep reference in its help. It is  
the best introduction to regular expression searching I've come  
across, using the PCRE syntax (recommended, most people will assume  
you use this variant).

> P.S. The regular expression search does not seem to work very  
> well : when you search for 'cla*', you get not only  
> 'documentclass...', but also 'cleardoublepage' or 'clos', 'cloche'.  
> The 'a' is not seen.

That is because the regular expression actually means something  
different:

Most characters just mean themselves. * means repeat the previous  
character zero or more times effectively cancelling the a in your  
case). + means repeat one or more times, ? means zero of once. The  
period (.) stands for any character. So "cla.*" should be closer to  
what you need, altough that will select until the end of the line.

The subject of regular expressions is rich and vast, so more direct  
questions will give more direct answers. As for your first question:

search for: \\index{(.+?)}
and then you can use \1 to insert the index-term in the replacement  
pattern. See the TextWrangler help for an explanation why this  
actually works. The question mark ensures that the shortest match is  
used. Nested {{}} pairs are still an issue. Be carefull, regular  
expressions are a form of programming, and can get complicated very  
quickly.

Maarten
------------------------- Helpful Info -------------------------
Mac-TeX Website: http://www.esm.psu.edu/mac-tex/
TeX FAQ: http://www.tex.ac.uk/faq
List Archive: http://tug.org/pipermail/macostex-archives/
List Reminders & Etiquette: http://www.esm.psu.edu/mac-tex/list/