void store_host_key(char *hostname, int port, char *keytype, char *key)
void store_host_key(const char *hostname, int port, const char *keytype, const char *key)
void store_host_key(char *hostname, int port, char *keytype, char *key){    FILE *fp;    int fd;    char filename[FILENAME_MAX];    make_filename(filename, INDEX_HOSTKEYS);    fd = open(filename, O_CREAT | O_APPEND | O_RDWR, 0600);    if (fd < 0) {	char dir[FILENAME_MAX];	make_filename(dir, INDEX_DIR);	mkdir(dir, 0700);	fd = open(filename, O_CREAT | O_APPEND | O_RDWR, 0600);    }    if (fd < 0) {	perror(filename);	exit(1);    }    fp = fdopen(fd, "a");    fprintf(fp, "%s@%d:%s %s\n", keytype, port, hostname, key);    fclose(fp);}