1 files changed, 107 insertions, 0 deletions
diff --git a/src/libudev/util.c b/src/libudev/util.c
index e447f89647..f625cfe99b 100644
--- a/src/libudev/util.c
+++ b/src/libudev/util.c
@@ -127,6 +127,113 @@ usec_t timespec_load(const struct timespec *ts) {
                 (usec_t) ts->tv_nsec / NSEC_PER_USEC;
 }
 
+char *format_timespan(char *buf, size_t l, usec_t t, usec_t accuracy) {
+        static const struct {
+                const char *suffix;
+                usec_t usec;
+        } table[] = {
+                { "y", USEC_PER_YEAR },
+                { "month", USEC_PER_MONTH },
+                { "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;
+        bool something = false;
+
+        assert(buf);
+        assert(l > 0);
+
+        if (t == (usec_t) -1)
+                return NULL;
+
+        if (t <= 0) {
+                snprintf(p, l, "0");
+                p[l-1] = 0;
+                return p;
+        }
+
+        /* The result of this function can be parsed with parse_sec */
+
+        for (i = 0; i < ELEMENTSOF(table); i++) {
+                int k;
+                size_t n;
+                bool done = false;
+                usec_t a, b;
+
+                if (t <= 0)
+                        break;
+
+                if (t < accuracy && something)
+                        break;
+
+                if (t < table[i].usec)
+                        continue;
+
+                if (l <= 1)
+                        break;
+
+                a = t / table[i].usec;
+                b = t % table[i].usec;
+
+                /* Let's see if we should shows this in dot notation */
+                if (t < USEC_PER_MINUTE && b > 0) {
+                        usec_t cc;
+                        int j;
+
+                        j = 0;
+                        for (cc = table[i].usec; cc > 1; cc /= 10)
+                                j++;
+
+                        for (cc = accuracy; cc > 1; cc /= 10) {
+                                b /= 10;
+                                j--;
+                        }
+
+                        if (j > 0) {
+                                k = snprintf(p, l,
+                                             "%s%llu.%0*llu%s",
+                                             p > buf ? " " : "",
+                                             (unsigned long long) a,
+                                             j,
+                                             (unsigned long long) b,
+                                             table[i].suffix);
+
+                                t = 0;
+                                done = true;
+                        }
+                }
+
+                /* No? Then let's show it normally */
+                if (!done) {
+                        k = snprintf(p, l,
+                                     "%s%llu%s",
+                                     p > buf ? " " : "",
+                                     (unsigned long long) a,
+                                     table[i].suffix);
+
+                        t = b;
+                }
+
+                n = MIN((size_t) k, l);
+
+                l -= n;
+                p += n;
+
+                something = true;
+        }
+
+        *p = 0;
+
+        return buf;
+}
+
 char* endswith(const char *s, const char *postfix) {
         size_t sl, pl;