openLink.cpp

#if defined(_WIN32)
#include <combaseapi.h> // CoInitializeEx
#include <objbase.h> // COINIT_APARTMENTTHREADED, COINIT_DISABLE_OLE1DDE
#include <shellapi.h> // ShellExecute
#include <winuser.h> // SW_SHOWNORMAL
#elif defined(__APPLE__)
#include <CoreFoundation/CFBase.h> // CFRelease
#include <CoreFoundation/CFString.h> // kCFStringEncodingASCII
#include <CoreFoundation/CFURL.h> // CFURLCreateWithBytes
#include <CoreServices/CoreServices.h> // LSOpenCFURLRef
#elif defined(EMSCRIPTEN)
#include <emscripten/emscripten.h> // EM_ASM_INT
#else
#include <stdlib.h> // system
#include <string.h> // memcpy, strlen
#endif

bool openLink(std::string url) {
#if defined(_WIN32)
	// https://docs.microsoft.com/en-us/windows/win32/api/combaseapi/nf-combaseapi-coinitializeex
	// https://docs.microsoft.com/en-us/windows/win32/api/objbase/ne-objbase-coinit
	// https://docs.microsoft.com/en-us/windows/win32/api/shellapi/nf-shellapi-shellexecutea
	// https://docs.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-showwindow
	static bool comInitialized = false;
	if (!comInitialized) {
		HRESULT status = CoInitializeEx(NULL, COINIT_APARTMENTTHREADED | COINIT_DISABLE_OLE1DDE);
		if (status != S_OK && status != S_FALSE) return false;
		comInitialized = true;
	}
	return ShellExecute(NULL, NULL, (LPCSTR)url.c_str(), NULL, NULL, SW_SHOWNORMAL) > 32;
#elif defined(__APPLE__)
	// https://developer.apple.com/documentation/corefoundation/1542075-cfurlcreatewithbytes?language=objc
	// https://developer.apple.com/documentation/corefoundation/cfstringbuiltinencodings?language=objc
	// https://developer.apple.com/documentation/coreservices/1442850-lsopencfurlref?language=objc
	// https://developer.apple.com/documentation/corefoundation/1521153-cfrelease?language=objc
	CFURLRef inURL = CFURLCreateWithBytes(NULL, (const UInt8*)url.c_str(), url.length(), kCFStringEncodingASCII, NULL);
	if (!inURL) return false;
	OSStatus status = LSOpenCFURLRef(inURL, NULL);
	CFRelease(inURL);
	return !status;
#elif defined(EMSCRIPTEN)
	// https://developer.mozilla.org/en-US/docs/Web/API/Window/open
	return EM_ASM_INT({
		return window.open(UTF8ToString($0)) !== null;
	}, url.c_str());
#else
	// Try your best!
	// https://man7.org/linux/man-pages/man3/system.3.html
	const char* prefix = "open ";
	char* command = new char[url.length() + strlen(prefix) + 1]();
	memcpy(command, prefix, strlen(prefix));
	memcpy(command + strlen(prefix), url.c_str(), url.length());
	int status = system(command);
	return status != -1 && status != 127;
#endif
}