tests/more: test argument --from-line

tests/by-util/test_more.rs

@@ -45,6 +45,40 @@ fn test_invalid_arg() {
  }
 }
 
+#[test]
+fn test_argument_from_file() {
+ if std::io::stdout().is_terminal() {
+ let scene = TestScenario::new(util_name!());
+ let at = &scene.fixtures;
+
+ let file = "test_file";
+
+ at.write(file, "1\n2");
+
+ // output all lines
+ scene
+ .ucmd()
+ .arg("-F")
+ .arg("0")
+ .arg(file)
+ .succeeds()
+ .no_stderr()
+ .stdout_contains("1")
+ .stdout_contains("2");
+
+ // output only the second line
+ scene
+ .ucmd()
+ .arg("-F")
+ .arg("2")
+ .arg(file)
+ .succeeds()
+ .no_stderr()
+ .stdout_contains("2")
+ .stdout_does_not_contain("1");
+ }
+}
+
 #[test]
 fn test_more_dir_arg() {
  // Run the test only if there's a valid terminal, else do nothing