parse_size
parse_size(res, optarg, "disk");
parse_size(res, optarg, "memory");
void parse_size(struct parse_result *, char *, const char *);
if ((res = parse_size(NULL, $2)) == -1) {
if ((res = parse_size($2, 0)) == -1) {
ssize_t parse_size(char *, int64_t);