filesystem.hh

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#ifndef DATAIO_FILESYSTEM_HH
#define DATAIO_FILESYSTEM_HH
 
#include <cstdlib>
#include <filesystem>
#include <string>
 
#include "../core/exceptions.hh"
#include "../core/types.hh"
#include "cfg_utils.hh"
 
namespace Utopia::DataIO {
 
 
std::string expanduser (const std::string& path) {
    using namespace std::string_literals;
 
    if (path.empty() or path.substr(0, 1) != "~"s) {
        return path;
    }
 
    const std::string HOME = std::getenv("HOME");
    if (HOME.empty()) {
        throw std::invalid_argument(
            "Cannot expand path because the environment variable 'HOME' was "
            "not set! Use an absolute path to specify the given path: "
            + path
        );
    }
    return HOME + path.substr(1, std::string::npos);
}
 
 
std::string get_abs_filepath (const Config& cfg) {
    using std::filesystem::path;
    using std::filesystem::current_path;
 
    const path filename = expanduser(get_as<std::string>("filename", cfg));
 
    path p = current_path();
    if (cfg["base_dir"]) {
        // By using append, we ensure that p remains an absolute path:
        //  - if base_dir is relative, will append, making it absolute
        //  - if base_dir is absolute, will overwrite current_path
        p.append(expanduser(get_as<std::string>("base_dir", cfg)));
    }
    p /= filename;
    return expanduser(p);
}
 
 
 
// end group Filesystem // end of group DataIO
 
} // namespace Utopia::DataIO
 
#endif // DATAIO_FILESYSTEM_HH