Add string::formatTime/formatTimeISO().

adapters/standalone.cpp

@@ -140,7 +140,7 @@ int main(int argc, char* argv[]) {
 #if defined ARCH_MAC
 	INFO("Bundle path: %s", asset::bundlePath.c_str());
 #endif
-	INFO("System time: %lf", system::getUnixTime());
+	INFO("System time: %s", string::formatTimeISO(system::getUnixTime()).c_str());
 
 	// Load settings
 	settings::init();

include/string.hpp

@@ -79,6 +79,9 @@ Examples:
 */
 std::vector<std::string> split(const std::string& s, const std::string& seperator, size_t maxTokens = 0);
 
+std::string formatTime(const char* format, double timestamp);
+std::string formatTimeISO(double timestamp);
+
 
 #if defined ARCH_WIN
 /** Performs a Unicode string conversion from UTF-16 to UTF-8.

src/string.cpp

@@ -1,3 +1,4 @@
+#include <ctime>
 #include <cctype> // for tolower and toupper
 #include <algorithm> // for transform and equal
 #include <libgen.h> // for dirname and basename
@@ -234,6 +235,18 @@ std::vector<std::string> split(const std::string& s, const std::string& separato
 }
 
 
+std::string formatTime(const char* format, double timestamp) {
+	time_t t = timestamp;
+	char str[1024];
+	size_t s = std::strftime(str, sizeof(str), format, std::localtime(&t));
+	return std::string(str, s);
+}
+
+std::string formatTimeISO(double timestamp) {
+	return formatTime("%FT%T%z", timestamp);
+}
+
+
 #if defined ARCH_WIN
 std::string UTF16toUTF8(const std::wstring& w) {
 	if (w.empty())