useradd: exit 19 for an invalid user name

src/uu/useradd/src/useradd.rs

@@ -78,6 +78,7 @@ mod exit_codes {
     pub const USERNAME_IN_USE: i32 = 9;
     pub const CANNOT_UPDATE_GROUP: i32 = 10;
     pub const CANNOT_CREATE_HOME: i32 = 12;
+    pub const BAD_NAME: i32 = 19;
 }
 
 // ---------------------------------------------------------------------------
@@ -105,6 +106,8 @@ enum UseraddError {
     CannotUpdateGroup(String),
     /// Exit 12 -- cannot create home directory.
     CannotCreateHome(String),
+    /// Exit 19 -- invalid user or group name.
+    BadName(String),
 }
 
 impl fmt::Display for UseraddError {
@@ -117,7 +120,8 @@ impl fmt::Display for UseraddError {
             | Self::GroupNotExist(msg)
             | Self::UsernameInUse(msg)
             | Self::CannotUpdateGroup(msg)
-            | Self::CannotCreateHome(msg) => f.write_str(msg),
+            | Self::CannotCreateHome(msg)
+            | Self::BadName(msg) => f.write_str(msg),
         }
     }
 }
@@ -135,6 +139,7 @@ impl UError for UseraddError {
             Self::UsernameInUse(_) => 9,
             Self::CannotUpdateGroup(_) => 10,
             Self::CannotCreateHome(_) => 12,
+            Self::BadName(_) => 19,
         }
     }
 }
@@ -545,8 +550,7 @@ fn parse_options(matches: &clap::ArgMatches) -> Result<UseraddOptions, UseraddEr
 #[allow(clippy::too_many_lines)]
 fn do_useradd(opts: &UseraddOptions) -> UResult<()> {
     // Step 1: Validate username.
-    validate::validate_username(&opts.login)
-        .map_err(|e| UseraddError::BadArgument(format!("{e}")))?;
+    validate::validate_username(&opts.login).map_err(|e| UseraddError::BadName(format!("{e}")))?;
 
     // Step 2: Block signals for the lock→write critical section only.
     // Dropped after file writes complete so home creation remains interruptible.
@@ -1684,6 +1688,10 @@ mod tests {
             UseraddError::CannotCreateHome(String::new()).code(),
             exit_codes::CANNOT_CREATE_HOME
         );
+        assert_eq!(
+            UseraddError::BadName(String::new()).code(),
+            exit_codes::BAD_NAME
+        );
     }
 
     // -----------------------------------------------------------------------

tests/by-util/test_useradd.rs

@@ -813,3 +813,21 @@ fn test_unusable_shadow_file_leaves_passwd_untouched() {
         "passwd was written although shadow could not be: {passwd:?}"
     );
 }
+
+#[test]
+fn test_invalid_name_exits_19() {
+    if crate::common::skip_unless_root() {
+        return;
+    }
+
+    let dir = setup_root_dir();
+    for name in ["bad:name", "1234"] {
+        let code = run_with_root(&dir, &["-M", "-N", name]);
+        assert_eq!(
+            code, 19,
+            "useradd(8): invalid user name should exit 19 ({name})"
+        );
+    }
+    let passwd = std::fs::read_to_string(dir.path().join("etc/passwd")).unwrap();
+    assert_eq!(passwd, "root:x:0:0:root:/root:/bin/bash\n");
+}