Re: [NTG-context] getting line numbers

3 Sep 2021

      On 9/3/2021 12:58 PM, Thierry Horsin via ntg-context wrote:
...
Hi everybody
Is there a way to have an automatic access to the current line number of a specific place inside a tex file ? To be more precise, here is what I would like to do.
I am currently trying to have some automatic external compilation by g++ of some portion of my tex file as in the following example below. \startC \stopC defines a framed part of text written between lines 538 and 549. Of course, if I add something before or inbetween my framed code, 538 and/or 549 will change. Thus I would like to get these two numbers automatically.
Thank you.
Thierry
\startC
#include <iostream>
using namespace std;
int mysum(int,int); int a; int b;
int main () { a=2; b=9;
   cout << mysum(a,b) << endl;
   return 0;
         }
int mysum(int a, int b)
{ return a+b; }
\stopC
\startluacode
myout = io.open("test.cpp", "w")
myin = io.open(tex.jobname..".tex", "r")
local n=0
for line in myin:lines() do
n=n+1
if n>539 and n<550 then
     myout:write(line.."\n")
  end
end
myout:close()
myin:close()
os.execute("g++ -o test test.cpp")
os.execute("./test > tmp")
local file=assert(io.open("tmp","r"))
local t = file:read("*all")
tex.print(t)
\stopluacode
in this case, thinking a bit different is easier ...
\starttext

\startbuffer[MyBuffer]
#include <iostream>

using namespace std;
int mysum(int,int);
int a; int b;
int main () {
     a=2; b=9;
     cout << mysum(a,b) << endl;
     return 0;
}
int mysum(int a, int b) {
     return a+b;
}
\stopbuffer

We compile and run:

\typebuffer[MyBuffer][option=C]

\startluacode
io.savedata("test.cpp",buffers.getcontent("MyBuffer"))
--os.execute("g++ -o test test.cpp")
--os.execute("./test > test.tmp")
os.execute("echo done > test.tmp")
buffers.assign("MyBuffer",io.loaddata("test.tmp"))
\stopluacode

And get:

\typebuffer[MyBuffer]

Or just:

\typefile{test.tmp}

\stoptext

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