dd: fix issue #5905 (different error msg from GNU) (#6622)

* Changed dd parsing error message to be in line with GNU dd

* Correct logic to make dd incorrect number error message fully compatible with GNU. Add test

---------

Co-authored-by: just-an-engineer <Julian.Beltz@zetier.com>

src/uu/dd/src/parseargs.rs

@@ -430,7 +430,7 @@ impl std::fmt::Display for ParseError {
                 write!(f, "Unrecognized conv=CONV -> {arg}")
             }
             Self::MultiplierStringParseFailure(arg) => {
-                write!(f, "Unrecognized byte multiplier -> {arg}")
+                write!(f, "invalid number: ‘{arg}’")
             }
             Self::MultiplierStringOverflow(arg) => {
                 write!(
@@ -474,8 +474,9 @@ fn show_zero_multiplier_warning() {
 }
 
 /// Parse bytes using str::parse, then map error if needed.
-fn parse_bytes_only(s: &str) -> Result<u64, ParseError> {
-    s.parse()
+fn parse_bytes_only(s: &str, i: usize) -> Result<u64, ParseError> {
+    s[..i]
+        .parse()
         .map_err(|_| ParseError::MultiplierStringParseFailure(s.to_string()))
 }
 
@@ -520,9 +521,9 @@ fn parse_bytes_no_x(full: &str, s: &str) -> Result<u64, ParseError> {
                 return Err(ParseError::InvalidNumber(full.to_string()))
             }
         },
-        (Some(i), None, None) => (parse_bytes_only(&s[..i])?, 1),
-        (None, Some(i), None) => (parse_bytes_only(&s[..i])?, 2),
-        (None, None, Some(i)) => (parse_bytes_only(&s[..i])?, 512),
+        (Some(i), None, None) => (parse_bytes_only(s, i)?, 1),
+        (None, Some(i), None) => (parse_bytes_only(s, i)?, 2),
+        (None, None, Some(i)) => (parse_bytes_only(s, i)?, 512),
         _ => return Err(ParseError::MultiplierStringParseFailure(full.to_string())),
     };
     num.checked_mul(multiplier)

tests/by-util/test_dd.rs

@@ -1775,3 +1775,16 @@ fn test_stdin_stdout_not_rewound_even_when_connected_to_seekable_file() {
     println!("stdout:\n{}", out_file_content);
     assert_eq!(out_file_content, "bde");
 }
+
+#[test]
+fn test_wrong_number_err_msg() {
+    new_ucmd!()
+        .args(&["count=kBb"])
+        .fails()
+        .stderr_contains("dd: invalid number: ‘kBb’\n");
+
+    new_ucmd!()
+        .args(&["count=1kBb555"])
+        .fails()
+        .stderr_contains("dd: invalid number: ‘1kBb555’\n");
+}