Implement -used.

This doesn't agree with find's output, but I think find is buggy here.
For example, find -used +0 is returning fewer results than find -used 1,
which makes no sense given that 1 is greater than 0.

3 files changed, 18 insertions, 0 deletions

diff --git a/bfs.h b/bfs.h
index 3a85650..1e38869 100644
--- a/bfs.h
+++ b/bfs.h
@@ -187,6 +187,7 @@ bool eval_access(const struct expr *expr, struct eval_state *state);
 
 bool eval_acmtime(const struct expr *expr, struct eval_state *state);
 bool eval_acnewer(const struct expr *expr, struct eval_state *state);
+bool eval_used(const struct expr *expr, struct eval_state *state);
 
 bool eval_gid(const struct expr *expr, struct eval_state *state);
 bool eval_uid(const struct expr *expr, struct eval_state *state);
diff --git a/eval.c b/eval.c
index 81d2de7..aae82cd 100644
--- a/eval.c
+++ b/eval.c
@@ -174,6 +174,21 @@ bool eval_acnewer(const struct expr *expr, struct eval_state *state) {
 }
 
 /**
+ * -used test.
+ */
+bool eval_used(const struct expr *expr, struct eval_state *state) {
+	const struct stat *statbuf = fill_statbuf(state);
+	if (!statbuf) {
+		return false;
+	}
+
+	time_t diff = timespec_diff(&statbuf->st_atim, &statbuf->st_ctim);
+	diff /= 60*60*24;
+	printf("%d\n", (int)diff);
+	return do_cmp(expr, diff);
+}
+
+/**
  * -gid test.
  */
 bool eval_gid(const struct expr *expr, struct eval_state *state) {
diff --git a/parse.c b/parse.c
index 2fc4fd8..154d566 100644
--- a/parse.c
+++ b/parse.c
@@ -1065,6 +1065,8 @@ static struct expr *parse_literal(struct parser_state *state) {
 	case  'u':
 		if (strcmp(arg, "-uid") == 0) {
 			return parse_test_icmp(state, eval_uid);
+		} else if (strcmp(arg, "-used") == 0) {
+			return parse_test_icmp(state, eval_used);
 		} else if (strcmp(arg, "-user") == 0) {
 			return parse_user(state);
 		}