source: branches/0.6-stable/lib/Gnuplot.cc @ 430

// $Id: Gnuplot.cc 430 2007-07-06 23:33:11Z peter $

/*
  Copyright (C) 2006 Jari Häkkinen, Peter Johansson

  This file is part of svndigest, http://trac.thep.lu.se/trac/svndigest

  svndigest is free software; you can redistribute it and/or modify it
  under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

  svndigest is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  02111-1307, USA.
*/

#include "Gnuplot.h"

#include <cstdio>
#include <string>
#include <unistd.h>

#include <iostream>


namespace theplu {
namespace svndigest {


  Gnuplot::Gnuplot(void)
    : linestyle_("steps"), pipe_(NULL)
  {
    acquire_program_path("gnuplot");
    if (gnuplot_binary_.empty())
      throw GnuplotException("Can't find gnuplot in your PATH");

    pipe_=popen(gnuplot_binary_.c_str(),"w");
    if (!pipe_)
      throw GnuplotException("Could not open connection to gnuplot");
  }


  Gnuplot::~Gnuplot(void)
  {
    if (pclose(pipe_) == -1)
      throw GnuplotException("Problem closing communication to gnuplot");
  }


  void Gnuplot::acquire_program_path(const std::string& progname)
  {
    char* env_path=getenv("PATH");
    if (!env_path)
      throw GnuplotException("Environment variable PATH is not set");

    std::list<std::string> paths;
    tokenizer(env_path,paths);
    for (std::list<std::string>::const_iterator i=paths.begin();
         i!=paths.end(); ++i) {
      std::string tmp((*i) + '/' + progname);
      if (!access(tmp.c_str(),X_OK)) {
        gnuplot_binary_=tmp;
        break;
      }
    }

    if (gnuplot_binary_.empty())
      throw GnuplotException("Cannot find '" + progname + "' in PATH");
  }

  
  int Gnuplot::command(const std::string& cmdstr)
  {
    if (fputs(cmdstr.c_str(),pipe_)==EOF)
      return EOF;
    if ((*(cmdstr.rbegin())!='\n') && (fputc('\n',pipe_)==EOF))
      return EOF;
    return fflush(pipe_);
  }


  void Gnuplot::tokenizer(const std::string& in,
                          std::list<std::string>& tokens,
                          const std::string& delimiters)
  {
    std::string::size_type previous_pos=in.find_first_not_of(delimiters,0);
    std::string::size_type position=in.find_first_of(delimiters,previous_pos);
    while ((std::string::npos!=position) || (std::string::npos!=previous_pos)) {
      tokens.push_back(in.substr(previous_pos, position-previous_pos));
      previous_pos=in.find_first_not_of(delimiters,position);
      position=in.find_first_of(delimiters,previous_pos);
    }
  }


}} // end of namespace svndigest and namespace theplu