cli: add an input subcommand

src/utils/string_ext.rs

@@ -0,0 +1,11 @@
+use isnt::std_1::primitive::IsntStrExt;
+
+pub trait StringExt {
+    fn to_string_if_not_empty(&self) -> Option<String>;
+}
+
+impl StringExt for str {
+    fn to_string_if_not_empty(&self) -> Option<String> {
+        self.is_not_empty().then(|| self.to_string())
+    }
+}