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

int
main(int argc, const char *argv[])
{
	if (argc != 3) {
		fprintf(stderr, "usage: mv from to\n");
		return 1;
	}

	if (rename(argv[1], argv[2]) < 0) {
		fprintf(stderr, "mv: %s\n", strerror(errno));
		return 1;
	}
}