+char *format_timespan(char *buf, size_t l, usec_t t) {
+ static const struct {
+ const char *suffix;
+ usec_t usec;
+ } table[] = {
+ { "w", USEC_PER_WEEK },
+ { "d", USEC_PER_DAY },
+ { "h", USEC_PER_HOUR },
+ { "min", USEC_PER_MINUTE },
+ { "s", USEC_PER_SEC },
+ { "ms", USEC_PER_MSEC },
+ { "us", 1 },
+ };
+
+ unsigned i;
+ char *p = buf;
+
+ assert(buf);
+ assert(l > 0);
+
+ if (t == (usec_t) -1)
+ return NULL;
+
+ /* The result of this function can be parsed with parse_usec */
+
+ for (i = 0; i < ELEMENTSOF(table); i++) {
+ int k;
+ size_t n;
+
+ if (t < table[i].usec)
+ continue;
+
+ if (l <= 1)
+ break;
+
+ k = snprintf(p, l, "%s%llu%s", p > buf ? " " : "", (unsigned long long) (t / table[i].usec), table[i].suffix);
+ n = MIN((size_t) k, l);
+
+ l -= n;
+ p += n;
+
+ t %= table[i].usec;
+ }
+
+ *p = 0;
+
+ return buf;
+}
+