Common paths for each system

src/dds/util/paths.hpp

+#pragma once
+
+#include <dds/util/fs.hpp>
+
+namespace dds {
+
+fs::path user_home_dir();
+fs::path user_data_dir();
+fs::path user_cache_dir();
+fs::path user_config_dir();
+
+inline fs::path dds_data_dir() { return user_data_dir() / "ddslim"; }
+inline fs::path dds_cache_dir() { return user_cache_dir() / "ddslim-cache"; }
+inline fs::path dds_config_dir() { return user_config_dir() / "ddslim"; }
+
+}  // namespace dds

src/dds/util/paths.linux.cpp

+#ifdef __linux__
+
+#include "./paths.hpp"
+
+#include <spdlog/spdlog.h>
+
+#include <cstdlib>
+
+using namespace dds;
+
+fs::path dds::user_home_dir() {
+    static auto ret = []() -> fs::path {
+        auto home_env = std::getenv("HOME");
+        if (!home_env) {
+            spdlog::warn("No HOME environment variable set!");
+            return "/";
+        }
+        return fs::absolute(fs::path(home_env));
+    }();
+    return ret;
+}
+
+fs::path dds::user_data_dir() {
+    static auto ret = []() -> fs::path {
+        auto xdg_data_home = std::getenv("XDG_DATA_HOME");
+        if (xdg_data_home) {
+            return fs::absolute(fs::path(xdg_data_home));
+        }
+        return user_home_dir() / ".local/share";
+    }();
+    return ret;
+}
+
+fs::path dds::user_cache_dir() {
+    static auto ret = []() -> fs::path {
+        auto xdg_cache_home = std::getenv("XDG_CACHE_HOME");
+        if (xdg_cache_home) {
+            return fs::absolute(fs::path(xdg_cache_home));
+        }
+        return user_home_dir() / ".cache";
+    }();
+    return ret;
+}
+
+fs::path dds::user_config_dir() {
+    static auto ret = []() -> fs::path {
+        auto xdg_config_home = std::getenv("XDG_CONFIG_HOME");
+        if (xdg_config_home) {
+            return fs::absolute(fs::path(xdg_config_home));
+        }
+        return user_home_dir() / ".config";
+    }();
+    return ret;
+}
+
+#endif

src/dds/util/paths.macos.cpp

+#ifdef __APPLE__
+
+#include "./paths.hpp"
+
+#include <spdlog/spdlog.h>
+
+#include <cstdlib>
+
+using namespace dds;
+
+fs::path dds::user_home_dir() {
+    static auto ret = []() -> fs::path {
+        auto home_env = std::getenv("HOME");
+        if (!home_env) {
+            spdlog::warn("No HOME environment variable set!");
+            return "/";
+        }
+        return fs::absolute(fs::path(home_env));
+    }();
+    return ret;
+}
+
+fs::path dds::user_data_dir() { return user_home_dir() / "Library/Application Support"; }
+fs::path dds::user_cache_dir() { return user_home_dir() / "Library/Caches"; }
+fs::path dds::user_config_dir() { return user_home_dir() / "Preferences"; }
+
+#endif

src/dds/util/paths.win.cpp

+#ifdef _WIN32
+
+#include "./paths.hpp"
+
+#include <spdlog/spdlog.h>
+
+#include <cstdlib>
+
+using namespace dds;
+
+fs::path dds::user_home_dir() {
+    static auto ret = []() -> fs::path {
+        auto userprofile_env = std::getenv("USERPROFILE");
+        if (!userprofile_env) {
+            spdlog::warn("No USERPROFILE environment variable set!");
+            return "/";
+        }
+        return fs::absolute(fs::path(userprofile_env));
+    }();
+    return ret;
+}
+
+namespace {
+
+fs::path appdatalocal_dir() {
+    auto env = std::getenv("LocalAppData");
+    assert(env);
+
+    return fs::absolute(fs::path(env));
+}
+
+fs::path appdata_dir() {
+    auto env = std::getenv("LocalAppData");
+    assert(env);
+
+    return fs::absolute(fs::path(env));
+}
+
+}  // namespace
+
+fs::path dds::user_data_dir() { return appdata_local_dir(); }
+fs::path dds::user_cache_dir() { return appdata_local_dir(); }
+fs::path dds::user_config_dir() { return appdata_dir(); }
+
+#endif