Thanks for your suggestion. I am trying to comment the following line new (&buf_cout) stdio_filebuf<char>(stdout, ios_base::out); new (&buf_cin) stdio_filebuf<char>(stdin, ios_base::in); new (&buf_cerr) stdio_filebuf<char>(stderr, ios_base::out); // cout.rdbuf(&buf_cout); cin.rdbuf(&buf_cin); cerr.rdbuf(&buf_cerr); clog.rdbuf(&buf_cerr); #ifdef _GLIBCXX_USE_WCHAR_T new (&buf_wcout) stdio_filebuf<wchar_t>(stdout, ios_base::out); new (&buf_wcin) stdio_filebuf<wchar_t>(stdin, ios_base::in); new (&buf_wcerr) stdio_filebuf<wchar_t>(stderr, ios_base::out); // wcout.rdbuf(&buf_wcout); wcin.rdbuf(&buf_wcin); I am trying to comment at two places above. and building my gcc. Thanks On Fri, Jan 6, 2012 at 3:16 PM, Jonathan Wakely <jwakely.gcc@xxxxxxxxx> wrote: > On 6 January 2012 09:45, Jonathan Wakely wrote: >> On 6 January 2012 09:28, naveen yadav wrote: >>> Dear All, >>> >>> I want to modify cout source code in GCC such that it will not print >>> any thing on the screen. >>> >>> The reason is I have very large already compile code(distrubited in >>> lib form) and it is not possible to recompile. so i left with no >>> option but to modify in GCC code. Will you pls let me know where I can do it . >> >> >> Can't you just redirect the program's output to /dev/null when you run >> the program? >> >> Or close the file descriptor in your program's main() function? >> >> Or duplicate the file descriptor in main() to redirect the output to a file? > > Or replace std::cout's streambuf with a different streambuf that > doesn't write to stdout. > > I could probably think of more ways to do it without altering the > standard library.