Hi Christopher and Early, ...I thought there is some standard Boost.Python stream somewhere anyway and didn't expect this kind of solution :) The code became longer than before (at least when calculating the definition of the sink class also) - but much more elegant :) Before: std::ostringstream oss; oss << "Hello, Python world!" << std::endl; std::string cs = oss.str(); PySys_WriteStdout(cs.c_str()); Now: boost::iostreams::stream<pysys_stdout_sink> pysys_stdout; pysys_stdout.open(pysys_stdout_sink()); pysys_stdout << "Hello, Python world!" << std::endl; (I had to add the line: pysys_stdout.open(pysys_stdout_sink()); to make it work.) Thank you very much for your help, Dietrich --- Here the code to play around with on unix/linux - maybe it is helpful for some other person with the same problem: mkdir -p /tmp/pysys_stdout cd /tmp/pysys_stdout cat > pysys_stdout.cpp <<FIN /* pysys_stdout.cpp */ #include <python2.5/Python.h> #include <algorithm> // min #include <iosfwd> // streamsize #include <boost/iostreams/categories.hpp> // sink_tag #include <boost/iostreams/stream.hpp> // stream #include <boost/format.hpp> // format class pysys_stdout_sink { public: typedef char char_type; typedef boost::iostreams::sink_tag category; std::streamsize write( const char* s, std::streamsize n ) { // PySys_WriteStdout truncates to 1000 chars static const std::streamsize MAXSIZE = 1000; std::streamsize written = std::min( n, MAXSIZE ); PySys_WriteStdout( (boost::format("%%.%1%s") % written).str().c_str(), s ); return written; } }; boost::iostreams::stream<pysys_stdout_sink> pysys_stdout; int main() { Py_Initialize(); pysys_stdout.open(pysys_stdout_sink()); pysys_stdout << "Hello, Python world!\n"; } /* fin */ FIN touch project-root.jam cat > Jamfile <<FIN # Jamfile # Python library lib python2.5 ; # Build pysys_stdout example exe pysys_stdout : pysys_stdout.cpp python2.5 ; # fin. FIN ls -l
total 8 -rw-r--r-- 1 dietrich dietrich 131 2009-05-14 22:56 Jamfile -rw-r--r-- 1 dietrich dietrich 0 2009-05-14 22:56 project-root.jam -rw-r--r-- 1 dietrich dietrich 982 2009-05-14 22:56 pysys_stdout.cpp
bjam
[...]
bin/gcc-4.3.3/debug/pysys_stdout
Hello, Python world!
On Wed, 2009-05-13 at 01:11 -0700, Christopher Currie wrote:
On Mon, May 11, 2009 at 2:17 PM, Early Ehlinger <earlye@gmail.com> wrote:
Basically, you need to create a streambuf class that calls PySys_WriteStdout() inside your_streambuf_class::sync().
It's probably fairly straightforward to do this using Boost.Iostreams, by creating a model of Sink:
include <Python.h>
#include <algorithm> // min #include <iosfwd> // streamsize #include <boost/iostreams/categories.hpp> // sink_tag #include <boost/iostreams/stream.hpp> // stream #include <boost/format.hpp> // format
class pysys_stdout_sink { public: typedef char char_type; typedef boost::iostreams::sink_tag category;
std::streamsize write( const char* s, std::streamsize n ) { // PySys_WriteStdout truncates to 1000 chars static const std::streamsize MAXSIZE = 1000;
std::streamsize written = std::min( n, MAXSIZE ); PySys_WriteStdout( (boost::format("%%.%1%s") % written).str().c_str(), s );
return written; } };
boost::iostreams::stream<pysys_stdout_sink> pysys_stdout;
int main() { Py_Initialize(); pysys_stdout << "Hello, Python world!\n"; }
HTH, Christopher _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users