strftime_test.c

#include <errno.h>
#include <stdio.h>
#include <time.h>

#include <glib.h>

/*
gcc -o strftime_test strftime_test.c `pkg-config --cflags --libs glib-2.0` && strftime_test
*/

void format_time(time_t time_to_use, const gchar *format)
{
	const struct tm *now_tm = localtime(&time_to_use);
	GDateTime *dt = g_date_time_new_from_unix_local(time_to_use);

	gchar *g_formatted;
	gchar formatted[8192];  // ridiculous huge buffer to ensure that is not the problem
	gsize len;

	len = strftime(formatted, 8192, format, now_tm);
	g_formatted = g_date_time_format(dt, format);
	printf("Format: %s:\n", format);
	if (len == 0)
		printf("CRT : Error: %s\n", g_strerror(errno));
	else
		printf("CRT : %s\n", formatted);
	printf("GLib: %s\n\n", g_formatted);
	g_free(g_formatted);
}


int main(int argc, char **argv)
{
	time_t now = time(NULL);

	format_time(now, "%a, %d %b %Y %T %z");
	format_time(now, "%a, %d %b %Y %T %Z");
	format_time(now, "%a, %d %b %Y %H:%M:%S %z");
	format_time(now, "%a, %d %b %Y %H:%M:%S %Z");

	return 0;
}