Add --linking-to filter option

adapter/sqlite/note_dao.go

@@ -384,6 +384,20 @@ func (d *NoteDAO) findRows(opts note.FinderOpts) (*sql.Rows, error) {
 				"("+strutil.JoinInt64(ids, ",")+")"),
 			)
 
+		case note.LinkingToFilter:
+			ids, err := d.findIdsByPathPrefixes(filter)
+			if err != nil {
+				return nil, err
+			}
+			if len(filter) == 0 {
+				break
+			}
+
+			whereExprs = append(whereExprs, fmt.Sprintf(
+				"n.id IN (SELECT source_id FROM links WHERE target_id IN %v)",
+				"("+strutil.JoinInt64(ids, ",")+")"),
+			)
+
 		case note.DateFilter:
 			value := "?"
 			field := "n." + dateField(filter)

adapter/sqlite/note_dao_test.go

@@ -500,6 +500,15 @@ func TestNoteDAOFindLinkedBy(t *testing.T) {
 	)
 }
 
+func TestNoteDAOFindLinkingTo(t *testing.T) {
+	testNoteDAOFindPaths(t,
+		note.FinderOpts{
+			Filters: []note.Filter{note.LinkingToFilter([]string{"log/2021-01-04", "ref/test/a.md"})},
+		},
+		[]string{"f39c8.md", "log/2021-01-03.md"},
+	)
+}
+
 func TestNoteDAOFindCreatedOn(t *testing.T) {
 	testNoteDAOFindPaths(t,
 		note.FinderOpts{

cmd/finder_opts.go

@@ -19,7 +19,8 @@ type Filtering struct {
 	Modified       string   `help:"Only the notes modified on the given date" placeholder:"<date>"`
 	ModifiedBefore string   `help:"Only the notes modified before the given date" placeholder:"<date>"`
 	ModifiedAfter  string   `help:"Only the notes modified after the given date" placeholder:"<date>"`
-	LinkedBy       []string `help:"Only the notes linked by the given notes" placeholder:"<path>"`
+	LinkedBy       []string `help:"Only the notes linked by the given notes" placeholder:"<path>" short:"l"`
+	LinkingTo      []string `help:"Only the notes linking to the given notes" placeholder:"<path>" short:"L"`
 	Exclude        []string `help:"Excludes notes matching the given file path pattern from the list" short:"x" placeholder:"<glob>"`
 	Interactive    bool     `help:"Further filter the list of notes interactively" short:"i"`
 }
@@ -124,6 +125,11 @@ func NewFinderOpts(zk *zk.Zk, filtering Filtering, sorting Sorting) (*note.Finde
 		filters = append(filters, note.LinkedByFilter(linkedByPaths))
 	}
 
+	linkingToPaths, ok := relPaths(zk, filtering.LinkingTo)
+	if ok {
+		filters = append(filters, note.LinkingToFilter(linkingToPaths))
+	}
+
 	if filtering.Interactive {
 		filters = append(filters, note.InteractiveFilter(true))
 	}

core/note/find.go

@@ -43,6 +43,9 @@ type ExcludePathFilter []string
 // LinkedByFilter is a note filter used to select notes being linked by another one.
 type LinkedByFilter []string
 
+// LinkingToFilter is a note filter used to select notes being linked by another one.
+type LinkingToFilter []string
+
 // DateFilter can be used to filter notes created or modified before, after or on a given date.
 type DateFilter struct {
 	Date      time.Time
@@ -57,6 +60,7 @@ func (f MatchFilter) sealed()       {}
 func (f PathFilter) sealed()        {}
 func (f ExcludePathFilter) sealed() {}
 func (f LinkedByFilter) sealed()    {}
+func (f LinkingToFilter) sealed()   {}
 func (f DateFilter) sealed()        {}
 func (f InteractiveFilter) sealed() {}