Simple header-only C++ ini parser and generator.

• Header-only.
• Both parsing and generating.
• Wide character support for native unicode on Windows.
• Default section support (similar to Python's ConfigParser).
• Interpolation support (i.e. variable substitution, similar to Python's ConfigParser).
• Simple design and implementation.
• Permissive MIT license.

#include <fstream>
#include "inipp.h"

int main() {
	inipp::Ini<char> ini;
	std::ifstream is("example.ini");
	ini.parse(is);
	std::cout << "raw ini file:" << std::endl;
	ini.generate(std::cout);
	ini.default_section(ini.sections["DEFAULT"]);
	ini.interpolate();
	std::cout << "ini file after default section and interpolation:" << std::endl;
	ini.generate(std::cout);
	int compression_level = -1;
	inipp::extract(ini.sections["bitbucket.org"]["CompressionLevel"], compression_level);
	std::cout << "bitbucket.org compression level: " << compression_level << std::endl;
	return 0;
}

• The section is set to the empty string.

• Every line is read from the file and trimmed from whitespace.

  • If line is empty or starts with ; then nothing happens.

  • Otherwise, if line starts with [ then section is changed to the string between [ and ]. If line does not end with ] then an error is reported.

  • Otherwise, if line contains an = sign, then all characters before = are treated as variable and all characters following = are treated as value. Both are trimmed. If the variable was already assigned earlier, an error is reported. Otherwise, the corresponding assigment is added to the section.

  • Otherwise, the line is reported as an error.

Insert every variable from the default section into every other section, without overwriting existing variables.

1. Locally within each section, every occurrence "${variable}" is replaced by "${section:variable}".
2. Every occurrence of "${section:variable}" is replaced by its value.
3. The previous step is repeated until no more replacements are possible, or until the recursion depth (by default, 10) is reached.