Re: Process only sections of a file? (newbie)

Gary wrote:
> Eric Blake wrote:
>> what you CAN do is redefine m4 builtins to have a different name, so
>> that they no longer clash with the rest of your text.  The manual
>> gives several examples of this, but a short summary would be:
>>
>> define(`m4include', defn(`include'))undefine(`include')
>
> Ah, okay. Thanks. When I read that section of the manual I didn't twig
> that you could also redefine the built in macros.

I guess I can't redefine brackets, can I :))

What I am basically trying to do is replace gpp -
http://en.nothingisreal.com/wiki/GPP (which works fine, btw, but seems
to lack any kind of support or ongoing development) - with m4, for the
purpose of building php scripts from smaller, self-contained,
"chunks". To make sure I don't include the same code twice, each chunk's
file uses a typical C/C++ -like guard:
,----
| #ifndef FOO
| #define FOO
| /*
| php code
| */
| #endif
`----

That's pretty easy syntax to read, for anyone who has ever used C. But
the equivalent m4 would be something like:
,----
| ifdef(`FOO', `',
| define(`FOO')
| /*
| php code
| */
| )
`----

(I think! although actually it doesn't seem to work if the define line
is included, so presumably I am going something wrong there) and I'm
worried that the end of the ifndef at the end of the file will just get
"lost" because it is very similar to php syntax and so far away from the
start of the macro.