+int strv_push_pair(char ***l, char *a, char *b) {
+ char **c;
+ unsigned n, m;
+
+ if (!a && !b)
+ return 0;
+
+ n = strv_length(*l);
+
+ /* increase and check for overflow */
+ m = n + !!a + !!b + 1;
+ if (m < n)
+ return -ENOMEM;
+
+ c = realloc_multiply(*l, sizeof(char*), m);
+ if (!c)
+ return -ENOMEM;
+
+ if (a)
+ c[n++] = a;
+ if (b)
+ c[n++] = b;
+ c[n] = NULL;
+
+ *l = c;
+ return 0;
+}
+
+int strv_push_prepend(char ***l, char *value) {
+ char **c;
+ unsigned n, m, i;
+
+ if (!value)
+ return 0;
+
+ n = strv_length(*l);
+
+ /* increase and check for overflow */
+ m = n + 2;
+ if (m < n)
+ return -ENOMEM;
+
+ c = new(char*, m);
+ if (!c)
+ return -ENOMEM;
+
+ for (i = 0; i < n; i++)
+ c[i+1] = (*l)[i];
+
+ c[0] = value;
+ c[n+1] = NULL;
+
+ free(*l);
+ *l = c;
+
+ return 0;
+}
+
+int strv_consume(char ***l, char *value) {
+ int r;
+
+ r = strv_push(l, value);
+ if (r < 0)
+ free(value);
+
+ return r;
+}
+
+int strv_consume_pair(char ***l, char *a, char *b) {
+ int r;
+
+ r = strv_push_pair(l, a, b);
+ if (r < 0) {
+ free(a);
+ free(b);
+ }
+
+ return r;
+}
+
+int strv_consume_prepend(char ***l, char *value) {
+ int r;
+
+ r = strv_push_prepend(l, value);
+ if (r < 0)
+ free(value);
+
+ return r;
+}
+