Environment.cpp

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/*
 *  CepGen: a central exclusive processes event generator
 *  Copyright (C) 2013-2024  Laurent Forthomme
 *
 *  This program 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 3 of the License, or
 *  any later version.
 *
 *  This program 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, see <http://www.gnu.org/licenses/>.
 */
 
#include <cstdlib>
 
#include "CepGen/Utils/Collections.h"
#include "CepGen/Utils/Filesystem.h"
#include "CepGen/Utils/String.h"
 
namespace cepgen {
  namespace utils {
    namespace env {
      std::string get(const std::string& var, const std::string& def) {
        if (const auto out = std::getenv(var.c_str()); out != nullptr)
          return std::string(out);
        return def;
      }
 
      std::vector<std::string> searchPaths() {
        const auto cepgen_path = fs::path(env::get("CEPGEN_PATH", "."));
        return std::vector<std::string>{cepgen_path,
                                        cepgen_path / "CepGen",
                                        cepgen_path / "lib",
                                        cepgen_path / "lib64",
                                        cepgen_path / "share" / "CepGen",
                                        fs::current_path(),
                                        fs::current_path().parent_path(),
                                        fs::current_path().parent_path().parent_path(),
                                        // additional paths for local builds
                                        cepgen_path / "External",
                                        cepgen_path / "build"};
      }
 
      void set(const std::string& var, const std::string& value) { setenv(var.c_str(), value.c_str(), 1); }
 
#ifdef _WIN32
      static constexpr char PATH_DELIM = ';';
#else
      static constexpr char PATH_DELIM = ':';
#endif
 
      void append(const std::string& var, const std::string& value) {
        auto env = split(env::get(var, ""), PATH_DELIM);
        env.emplace_back(value);
        normalise(env);
        setenv(var.c_str(), merge(env, std::string(1, PATH_DELIM)).c_str(), 1);
      }
 
      void unset(const std::string& var) { unsetenv(var.c_str()); }
    }  // namespace env
  }  // namespace utils
}  // namespace cepgen