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/*
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 * Outputs the value of time(2) with the 16 least significant bits zeroed out.
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 * For use in context keyed payload encoding.
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 *
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 * Author: Dimitris Glynos <dimitris at census-labs.com>
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 */
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#include <stdlib.h>
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#include <stdio.h>
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#define __USE_XOPEN
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#include <time.h>
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char *app = NULL;
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void croak_usage(void)
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{
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	fprintf(stderr, "usage: %s [date & time]\n"
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		"\tSupported date & time format: 'YYYY-MM-DD HH:MM:SS'\n"
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		"\te.g. %s '2003-11-04 14:23:10'\n",
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		app, app);
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	exit(1);
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}
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time_t parse_time(const char *input)
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{
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	struct tm t;
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	char *p;
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	p = strptime(input, "%Y-%m-%d %H:%M:%S", &t);
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	if ((!p) || (*p != '\0')) {
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		fprintf(stderr, "error while processing time spec!\n");
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		croak_usage();
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	}
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	return mktime(&t);
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}
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int main(int argc, char *argv[])
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{
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	time_t t;
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	app = argv[0];
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	if (argc > 2)
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		croak_usage();
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	if (argc == 2) 
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		t = parse_time(argv[1]);
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	else 
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		t = time(NULL);
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	printf("%#.8lx\n", t & 0xffff0000);
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	return 0;
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}
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