EnvironmentVariables.cc

/**************************************************************************
 * basf2 (Belle II Analysis Software Framework)                           *
 * Author: The Belle II Collaboration                                     *
 *                                                                        *
 * See git log for contributors and copyright holders.                    *
 * This file is licensed under LGPL-3.0, see LICENSE.md.                  *
 **************************************************************************/
 
#include <framework/utilities/EnvironmentVariables.h>
#include <boost/algorithm/string.hpp>
#include <boost/python/import.hpp>
#include <boost/python/extract.hpp>
#include <algorithm>
#include <cstdlib>
 
namespace Belle2 {
 
  bool EnvironmentVariables::isSet(const std::string& name)
  {
    char* envValue = std::getenv(name.c_str());
    return envValue != nullptr;
  }
 
  std::string EnvironmentVariables::get(const std::string& name, const std::string& fallback)
  {
    char* envValue = std::getenv(name.c_str());
    if (envValue != nullptr) {
      std::string val(envValue);
      boost::trim(val);
      return envValue;
    }
    return fallback;
  }
 
  std::vector<std::string> EnvironmentVariables::getList(const std::string& name, const std::vector<std::string>& fallback,
                                                         const std::string& separators)
  {
    if (!isSet(name))
      return fallback;
    std::string value = get(name);
    std::vector<std::string> items;
    // Treat an empty string as empty list
    if (value.empty())
      return items;
    // We have something to return: split the string, trim each element and remove empty ones before returning
    boost::split(items, value, boost::is_any_of(separators));
    std::for_each(items.begin(), items.end(), [](std::string & s) {boost::algorithm::trim(s);});
    items.erase(std::remove_if(items.begin(), items.end(), [](const std::string & s) { return s.empty(); }), items.end());
    return items;
  }
 
  std::vector<std::string> EnvironmentVariables::getOrCreateList(const std::string& name, const std::string& fallback,
      const std::string& separators)
  {
    // Almost the same as above but we don't need to check if its set, we just parse the value or fallback into a list
    std::string value = get(name, fallback);
    std::vector<std::string> items;
    // Treat an empty string as empty list
    if (value.empty())
      return items;
    // We have something to return: split the string, trim each element and remove empty ones before returning
    boost::split(items, value, boost::is_any_of(separators));
    std::for_each(items.begin(), items.end(), [](std::string & s) {boost::algorithm::trim(s);});
    items.erase(std::remove_if(items.begin(), items.end(), [](const std::string & s) { return s.empty(); }), items.end());
    return items;
  }
 
  std::string EnvironmentVariables::expand(const std::string& text)
  {
    // we could implement this ourselves ... but that seems like a waste of
    // time since there's a perfectly good implementation available.
    namespace py = boost::python;
    py::object path = py::import("os.path");
    return py::extract<std::string>(path.attr("expandvars")(text));
  }

}