A cross-platform library that provides a simple API to read and write INI-style configuration files. It supports data files in ASCII, MBCS and Unicode. It is designed explicitly to be portable to any platform and has been tested on Windows, WinCE and Linux. Released as open-source and free using the MIT licence.
- MIT Licence allows free use in all software (including GPL and commercial)
- multi-platform: Windows (from 95 to 11, CE), Linux, MacOS
- loading and saving of INI-style configuration files
- configuration files can have any newline format on all platforms
- liberal acceptance of file format
- key/values with no section, keys with no value
- removal of whitespace around sections, keys and values
- support for multi-line values (values with embedded newline characters)
- optional support for multiple keys with the same name
- optional case-insensitive sections and keys (for ASCII characters only)
- saves files with sections and keys in the same order as they were loaded
- preserves comments on the file, section and keys where possible
- supports both char or wchar_t programming interfaces
- supports both MBCS (system locale) and UTF-8 file encodings
- supports ICU as conversion library on all platforms
- system locale does not need to be UTF-8 on Linux/Unix to load UTF-8 file
- support for non-ASCII characters in section, keys, values and comments
- support for non-standard character types or file encodings via user-written converter classes
- support for adding/modifying values programmatically
- should compile with no warnings in most compilers
Full documentation of the interface is available in doxygen format. See latest documentation here.
SimpleIni is a header-only library. No building is required to use it in your project.
Simply include SimpleIni.h in your source files:
#include "SimpleIni.h"That's it! The library is ready to use.
While the library itself doesn't require building, you can build and run the test suite using CMake. A top-level Makefile wraps the usual CMake workflow for local development:
make help # list targets
make check # format-check, build, and test
make format # apply clang-format
make format-check # verify formatting
make test # run ctest
make clean # remove build/Requires cmake, a C++17 compiler, and clang-format for format targets. Test builds use -Werror. CMake remains the build system.
CI (.github/workflows/build-and-test.yml) runs make format-check on Linux only; tests run on Linux (x64 and arm64), Windows, and macOS.
Direct CMake usage:
# Configure the project
cmake -S . -B build
# Build the tests (optional)
cmake --build build
# To build without tests
cmake -S . -B build -DBUILD_TESTING=OFF
cmake --build build
# Run all tests
cd build
ctest --verboseTo use SimpleIni in your CMake project:
# Add SimpleIni as a subdirectory
add_subdirectory(simpleini)
# Link against your target
target_link_libraries(your_target PRIVATE SimpleIni::SimpleIni)Or install it system-wide:
cmake -S . -B build
cmake --build build
sudo cmake --install buildThen in your CMake project:
find_package(SimpleIni REQUIRED)
target_link_libraries(your_target PRIVATE SimpleIni::SimpleIni)Note that SI_CONVERT_GENERIC is not the default conversion mode. When enabled,
UTF-8 conversion is built into the header; no additional source files are required.
Earlier releases shipped ConvertUTF.c and ConvertUTF.h for SI_CONVERT_GENERIC
and expected you to compile them into your project. UTF-8 conversion is now inline
in SimpleIni.h. Remove any ConvertUTF.c / ConvertUTF.h from your build and
drop links to ConvertUTF.c; no replacement source files are required.
These snippets are included with the distribution in the automatic tests as ts-snippets.cpp.
// simple demonstration
CSimpleIniA ini;
ini.SetUnicode();
SI_Error rc = ini.LoadFile("example.ini");
if (rc < 0) { /* handle error */ };
ASSERT_EQ(rc, SI_OK);
const char* pv;
pv = ini.GetValue("section", "key", "default");
ASSERT_STREQ(pv, "value");
ini.SetValue("section", "key", "newvalue");
pv = ini.GetValue("section", "key", "default");
ASSERT_STREQ(pv, "newvalue"); // load from a data file
CSimpleIniA ini;
SI_Error rc = ini.LoadFile("example.ini");
if (rc < 0) { /* handle error */ };
ASSERT_EQ(rc, SI_OK);
// load from a string
const std::string example = "[section]\nkey = value\n";
CSimpleIniA ini;
SI_Error rc = ini.LoadData(example);
if (rc < 0) { /* handle error */ };
ASSERT_EQ(rc, SI_OK); // get all sections
CSimpleIniA::TNamesDepend sections;
ini.GetAllSections(sections);
// get all keys in a section
CSimpleIniA::TNamesDepend keys;
ini.GetAllKeys("section1", keys); // get the value of a key that doesn't exist
const char* pv;
pv = ini.GetValue("section1", "key99");
ASSERT_EQ(pv, nullptr);
// get the value of a key that does exist
pv = ini.GetValue("section1", "key1");
ASSERT_STREQ(pv, "value1");
// get the value of a key which may have multiple
// values. If hasMultiple is true, then there are
// multiple values and just one value has been returned
bool hasMulti;
pv = ini.GetValue("section1", "key1", nullptr, &hasMulti);
ASSERT_STREQ(pv, "value1");
ASSERT_EQ(hasMulti, false);
pv = ini.GetValue("section1", "key2", nullptr, &hasMulti);
ASSERT_STREQ(pv, "value2.1");
ASSERT_EQ(hasMulti, true);
// get all values of a key with multiple values
CSimpleIniA::TNamesDepend values;
ini.GetAllValues("section1", "key2", values);
// sort the values into a known order, in this case we want
// the original load order
values.sort(CSimpleIniA::Entry::LoadOrder());
// output all of the items
CSimpleIniA::TNamesDepend::const_iterator it;
for (it = values.begin(); it != values.end(); ++it) {
printf("value = '%s'\n", it->pItem);
} // add a new section
rc = ini.SetValue("section1", nullptr, nullptr);
if (rc < 0) { /* handle error */ };
ASSERT_EQ(rc, SI_INSERTED);
// not an error to add one that already exists
rc = ini.SetValue("section1", nullptr, nullptr);
if (rc < 0) { /* handle error */ };
ASSERT_EQ(rc, SI_UPDATED);
// get the value of a key that doesn't exist
const char* pv;
pv = ini.GetValue("section2", "key1", "default-value");
ASSERT_STREQ(pv, "default-value");
// adding a key (the section will be added if needed)
rc = ini.SetValue("section2", "key1", "value1");
if (rc < 0) { /* handle error */ };
ASSERT_EQ(rc, SI_INSERTED);
// ensure it is set to expected value
pv = ini.GetValue("section2", "key1", nullptr);
ASSERT_STREQ(pv, "value1");
// change the value of a key
rc = ini.SetValue("section2", "key1", "value2");
if (rc < 0) { /* handle error */ };
ASSERT_EQ(rc, SI_UPDATED);
// ensure it is set to expected value
pv = ini.GetValue("section2", "key1", nullptr);
ASSERT_STREQ(pv, "value2"); // deleting a key from a section. Optionally the entire
// section may be deleted if it is now empty.
bool done, deleteSectionIfEmpty = true;
done = ini.Delete("section1", "key1", deleteSectionIfEmpty);
ASSERT_EQ(done, true);
done = ini.Delete("section1", "key1");
ASSERT_EQ(done, false);
// deleting an entire section and all keys in it
done = ini.Delete("section2", nullptr);
ASSERT_EQ(done, true);
done = ini.Delete("section2", nullptr);
ASSERT_EQ(done, false); // save the data to a string
std::string data;
rc = ini.Save(data);
if (rc < 0) { /* handle error */ };
ASSERT_EQ(rc, SI_OK);
// save the data back to the file
rc = ini.SaveFile("example2.ini");
if (rc < 0) { /* handle error */ };
ASSERT_EQ(rc, SI_OK);