data_path.cpp

#include "data_path.hpp"

#include <iostream>
#include <vector>
#include <sstream>

#if defined(_WIN32)
#include <windows.h>
#include <Knownfolders.h>
#include <Shlobj.h>
#include <direct.h>
#include <io.h>
#elif defined(__APPLE__)
#include <mach-o/dyld.h>
#elif defined(__linux__)
#include <unistd.h>
#include <sys/stat.h>
#endif //WINDOWS

//get_data_path() gets the directory containing the executable
//  (...or the Resources directory on OSX if the code appears to be running in an app bundle)

static std::string get_data_path() {
	#if defined(_WIN32)
	//See: https://stackoverflow.com/questions/1023306/finding-current-executables-path-without-proc-self-exe
	TCHAR buffer[MAX_PATH];
	GetModuleFileName(NULL, buffer, MAX_PATH);
	std::string ret = buffer;
	ret = ret.substr(0, ret.rfind('\\'));
	return ret;

	#elif defined(__linux__)
	//From: https://stackoverflow.com/questions/933850/how-do-i-find-the-location-of-the-executable-in-c
	std::vector< char > buffer(1000);
	while (1) {
		ssize_t got = readlink("/proc/self/exe", &buffer[0], buffer.size());
		if (got <= 0) {
			return "";
		} else if (got < (ssize_t)buffer.size()) {
			std::string ret = std::string(buffer.begin(), buffer.begin() + got);
			return ret.substr(0, ret.rfind('/'));
		}
		buffer.resize(buffer.size() + 4000);
	}

	#elif defined(__APPLE__)
	//From: https://stackoverflow.com/questions/799679/programmatically-retrieving-the-absolute-path-of-an-os-x-command-line-app/1024933
	uint32_t bufsize = 0;
	std::vector< char > buffer;
	_NSGetExecutablePath(&buffer[0], &bufsize);
	buffer.resize(bufsize, '\0');
	bufsize = buffer.size();
	if (_NSGetExecutablePath(&buffer[0], &bufsize) != 0) {
		throw std::runtime_error("Call to _NSGetExecutablePath failed for mysterious reasons.");
	}
	std::string ret = std::string(&buffer[0]);
	ret = ret.substr(0, ret.rfind('/'));

	//If running inside an .app bundle, point to the Resources directory:
	if (ret.rfind(".app/Contents/MacOS") == ret.size() - std::string(".app/Contents/MacOS").size()) {
		ret = ret.substr(0, ret.size() - 5) + "Resources";
	}

	return ret;
	#else
	#error "No idea what the OS is."
	#endif
}

std::string data_path(std::string const &suffix) {
	static std::string path = get_data_path();
	return path + "/" + suffix;
}