Add C interface

include/cppIni/cppIni_c.h

@@ -0,0 +1,44 @@
+// cppIni - A C++20 library for reading and writing INI files
+// Copyright (C) 2023-2024 Nils Hofmann <nils.friedchen@googlemail.com>
+//
+// 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
+// (at your option) 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 <https://www.gnu.org/licenses/>.
+
+#pragma once
+
+#include <stdlib.h>
+#include <cppIni/cppini_export.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef void* pFile;
+/// \file cppIni_c.h
+/// \brief The C API for cppIni
+///
+/// \details
+/// This file contains the C API for cppIni. It is a very thin wrapper around
+/// the C++ API. It is intended for use with languages that do not support
+/// C++.
+
+CPPINI_EXPORT pFile cppIni_open(const char* filename); ///< Opens a file
+CPPINI_EXPORT void cppIni_close(pFile* file); ///< Closes a file
+CPPINI_EXPORT void cppIni_set(pFile file, const char* section, const char* key, const char* value); ///< Sets a value
+CPPINI_EXPORT const char* cppIni_gets(pFile file, const char* section, const char* key, char* out, size_t outSize); ///< Gets a string
+CPPINI_EXPORT int cppIni_geti(pFile file, const char* section, const char* key); ///< Gets an integer
+CPPINI_EXPORT float cppIni_getf(pFile file, const char* section, const char* key); ///< Gets a float
+
+#ifdef __cplusplus
+}
+#endif

src/CInterface.cpp

@@ -0,0 +1,84 @@
+// cppIni - A C++20 library for reading and writing INI files
+// Copyright (C) 2023-2024 Nils Hofmann <nils.friedchen@googlemail.com>
+//
+// 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
+// (at your option) 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 <https://www.gnu.org/licenses/>.
+
+#include <cstring>
+
+#include <cppIni/cppIni_c.h>
+#include <cppIni/cppIni.h>
+
+/// Opens a file for reading and writing. Throws an exception if the file cannot
+/// be opened.
+///
+/// \param[in] filename The name of the file to open
+/// \return A pointer to a File object
+pFile cppIni_open(const char* filename)
+{
+    return new File(filename);
+}
+
+/// Closes a file that was opened with cppIni_open().
+/// \param[in] file A pointer to a File object
+void cppIni_close(pFile* file)
+{
+    delete static_cast<File*>(*file);
+}
+
+/// \param[in] file A pointer to a File object
+/// \param[in] section The name of the section to add
+/// \param[in] key The name of the key to add
+/// \param[in] value The value to add
+void cppIni_set(pFile file, const char* section, const char* key, const char* value)
+{
+    static_cast<File*>(file)->set(section, key, value);
+}
+
+/// \param[in] file A pointer to a File object
+/// \param[in] section The name of the section to get
+/// \param[in] key The name of the key to get
+/// \param[out] out A buffer to store the value in
+/// \param[in] outSize The size of the buffer
+/// \return A pointer to the buffer
+const char* cppIni_gets(pFile file, const char* section, const char* key, char* out, size_t outSize)
+{
+    const auto value = static_cast<File*>(file)->get<std::string>(section, key);
+
+    if (value.empty()) {
+        return out;
+    }
+
+    std::strncpy(out, value.data(), outSize);
+    return out;
+}
+
+/// \see cppIni_gets
+/// \param[in] file A pointer to a File object
+/// \param[in] section The name of the section to get
+/// \param[in] key The name of the key to get
+/// \return The value of the key
+int cppIni_geti(pFile file, const char* section, const char* key)
+{
+    return static_cast<File*>(file)->get<int>(section, key);
+}
+
+/// \see cppIni_gets
+/// \param[in] file A pointer to a File object
+/// \param[in] section The name of the section to get
+/// \param[in] key The name of the key to get
+/// \return The value of the key
+float cppIni_getf(pFile file, const char* section, const char* key)
+{
+    return static_cast<File*>(file)->get<float>(section, key);
+}

src/CMakeLists.txt

@@ -3,13 +3,15 @@ cmake_minimum_required(VERSION 3.24)
 set(CMAKE_DEBUG_POSTFIX d)
 
 set(SOURCES
+    CInterface.cpp
     Entry.cpp
     File.cpp
     Section.cpp
 )
 
 set(API_HEADERS
     cppIni.h
+    cppIni_c.h
     Entry.h
     File.h
     Section.h

tests/CInterfaceTest.cpp

@@ -0,0 +1,99 @@
+// cppIni - A C++20 library for reading and writing INI files
+// Copyright (C) 2023-2024 Nils Hofmann <nils.friedchen@googlemail.com>
+//
+// 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
+// (at your option) 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 <https://www.gnu.org/licenses/>.
+
+#include <array>
+#include <filesystem>
+#include <format>
+
+#include <cppIni/cppIni_c.h>
+#include <doctest/doctest.h>
+
+static const std::string fileName = std::format("{}{}", WORKING_DIR, "/res/test.ini");;
+
+TEST_SUITE_BEGIN("CInterface");
+
+TEST_CASE("Construction of File object")
+{
+    void* file;
+    CHECK_NOTHROW(file = cppIni_open(fileName.c_str()));
+    CHECK_NE(file, nullptr);
+    CHECK_NOTHROW(cppIni_close(&file));
+}
+
+struct ScopeGuard
+{
+    ScopeGuard(pFile file) : file(file){};
+    ~ScopeGuard(){ cppIni_close(&file); };
+    pFile file;
+};
+
+TEST_CASE("Read a string entry")
+{
+    void* file = cppIni_open(fileName.c_str());
+    ScopeGuard guard{file};
+
+    std::array<char, 64> buffer{0};
+    cppIni_gets(file, "Section1", "Entry1", buffer.data(), buffer.size());
+
+    CHECK_EQ(std::string_view{buffer.data()}, "Value1");
+}
+
+TEST_CASE("Try to read a non-existing entry")
+{
+    void* file = cppIni_open(fileName.c_str());
+    ScopeGuard guard{file};
+
+    std::array<char, 64> buffer{0};
+    CHECK_EQ(cppIni_gets(file, "Section1", "NonExistingEntry", buffer.data(), buffer.size()), buffer.data());
+    CHECK_EQ(buffer[0], '\0');
+}
+
+TEST_CASE("Change a value")
+{
+    constexpr auto tempFileName = "tmp.ini";
+    std::filesystem::copy_file(fileName, tempFileName);
+
+    {
+        constexpr auto newValue = 1337;
+        void* file = cppIni_open(tempFileName);
+        ScopeGuard guard{file};
+
+        const auto previousValue = cppIni_geti(file, "Section1", "IntEntry");
+        CHECK_NE(previousValue, newValue);
+        cppIni_set(file, "Section1", "IntEntry", std::to_string(newValue).c_str());
+        CHECK_EQ(cppIni_geti(file, "Section1", "IntEntry"), newValue);
+    }
+
+    std::filesystem::remove(tempFileName);
+}
+
+TEST_CASE("Read an integer entry")
+{
+    void* file = cppIni_open(fileName.c_str());
+    ScopeGuard guard{file};
+
+    CHECK_EQ(cppIni_geti(file, "Section1", "IntEntry"), 42);
+}
+
+TEST_CASE("Read a floating point value entry")
+{
+    void* file = cppIni_open(fileName.c_str());
+    ScopeGuard guard{file};
+
+    CHECK_LT(std::abs(cppIni_getf(file, "Section1.Subsection1", "DoubleEntry") - 3.1415), 0.001);
+}
+
+TEST_SUITE_END();

tests/CMakeLists.txt

@@ -6,6 +6,7 @@ set(TEST_SOURCES
     EntryTest.cpp
     FileTest.cpp
     SectionTest.cpp
+    CInterfaceTest.cpp
 )
 
 add_executable(${PROJECT_NAME}_tests ${TEST_SOURCES})