Mfcttrf

I need to include file, but I want to manipulate it directly from PDFLaTeX.
I must remove any text which is betweem and , including backslashes and parenthesis. I have tried many escaping options, but the best I could get it this and it is not working:

input

Is this possible at all?

This works for me (with pdflatex -shell-escape, of course) and prints just “abc”.

beginfilecontents*jobname-test.tex
abcdef
endfilecontents*

documentclassarticle

begindocument

input

enddocument

The issue is that TeX performs macro expansion on the argument to input; with string\ we nullify the macro nature of \.

I use jobname just for avoiding the risk of clobbering my files.

If you want a non-greedy replacement, it's a bit more complicated (you could use Perl, instead). The search string should be something like

\[^\]*\}

This can be more easily accomplished by defining the string beforehand:

beginfilecontents*jobname-test.tex
abcdefghijkl
endfilecontents*

documentclassarticle

begindocument

edefsearchstringstring\string[^string\string]*string\string}
input

enddocument

In this case the output would by “abcghi”.

Assuming you're free to use LuaLaTeX, and assuming further that the material between and (including the delimiters) is all on one line, the following solution should work just fine for you.

The solution consists of a Lua function (stored in an external file) and two LaTeX macros; the first assigns the Lua function to the process_input_buffer callback, making it act like a preprocessor, and the second removes the preprocessor-like operation of the Lua function.

The pattern-matching operation, "\.-\", uses .- rather than -* to match "zero or more instances of any character". Observe that using -* would be a mistake here, as it would make Lua perform a "greedy" match and thus inappropriately obliterate the middle substring, uvw.

RequirePackagefilecontents
%% External file with " ... " material
beginfilecontents*cxf.tex
$abc ... uvw int_0^1 xyz$

abc ... uvw int_0^1 xyz
endfilecontents*

% Place the Lua code in a separate external file
beginfilecontents*external.lua
function remove_braced_stuff ( s )
 return ( s:gsub ( "\.-\" , "" ) )
end
endfilecontents*

documentclassarticle
%% Load the Lua function from the external file
directluadofile("external.lua")

%% Two utility LaTeX macros
newcommandRemoveBracedStuffdirectlua
 luatexbase.add_to_callback ( "process_input_buffer" , 
 remove_braced_stuff , "removestuff" )
newcommandDontRemoveBracedStuffdirectlua
 luatexbase.remove_from_callback ( "process_input_buffer" , 
 "removestuff" )

begindocument
RemoveBracedStuff % Enable the Lua function
input cxf % Load the external file

DontRemoveBracedStuff % Disable the Lua function
%% remainder of document
enddocument