[Rcpp-devel] rout and rerr instead of cout and cerr in Rcpp - Rcpp-devel

Sean Robert McGuffee · 2011-04-28T01:26:41Z

>On 11/10/2009 12:23 PM, Dirk Eddelbuettel wrote: >> > >> > On 10 November 2009 at 09:47, Romain Fran?ois wrote: >> > | Hi, >> > | >> > | Would it make sense to have an rout and rerr so that we could do : >> > | >> > | rout > > | >> > | and >> > | >> > | rerr > > | >> > | and this would go into Rprintf and REprintf ? or maybe we can directly >> > | redefine cout and cerr >> > >> > Hm. That never really arose in my use. cout was mostly for debugging

[Rcpp-devel] rout and rerr instead of cout and cerr in Rcpp

Sean Robert McGuffee

Wed, Apr 27, 2011 6:26 PM #

Has anyone followed up on this? I?m wondering if there might be a simple way
to redirect cerr and cout to something like an rerr and rout? I for one have
thousands of lines of code that use cerr and cout in libraries that I would
like to use in R. It seems that they currently are causing a crash at
run-time when I leave those lines in my packages. I won?t know for sure
until I take the time to remove all of them, but who knows how long that
might take. I think it would probably be faster and easier for me to
redirect these streams to R somehow. Has that been worked out yet? If so,
how? If not, I think maybe I can redirect them to some log files or
something. Has anyone done that?
Thanks,
Sean
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Sean Robert McGuffee

Wed, Apr 27, 2011 7:27 PM #

Just to follow up myself, it turns out that it?s easy to redirect cerr and
cout to files, and that solves all my issues.
In case anyone is interested, here is how I did it:


#include<ostream>
#include<fstream>

RcppExport SEXP myfunction(SEXP params)
{
    try
    { // or use BEGIN_RCPP macro

        //start off by redirecting
        streambuf* save_sbuf_fout;
        streambuf* save_sbuf_ferr;
        streambuf* save_sbuf_cout;
        streambuf* save_sbuf_cerr;
        ofstream fout;
        ofstream ferr;
        fout.open("cout.txt");
        ferr.open("cerr.txt");
        save_sbuf_cout = cout.rdbuf();
        save_sbuf_cerr = cerr.rdbuf();
        save_sbuf_fout = fout.rdbuf();
        save_sbuf_ferr = ferr.rdbuf();
        cout.rdbuf(save_sbuf_fout);
        cerr.rdbuf(save_sbuf_ferr);

        /*do whatever I normally do and write to cerr and/or cout all I
want*/

        //revert to original state
        cout.rdbuf(save_sbuf_cout);
        cerr.rdbuf(save_sbuf_cerr);
        fout.close();
        ferr.close();

    }
}

On 4/27/11 9:26 PM, "Sean Robert McGuffee" <sean.mcguffee at gmail.com> wrote:

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